Просмотр кода страницы Английская Википедия:Ethanol fuel in the United States

{{Английская Википедия/Панель перехода}}
{{Main article|Biofuel in the United States|Ethanol fuel}}
{{Use mdy dates|date=December 2021}}
{{Update|date=May 2019}}
[[File:Corn vs Ethanol production.webp|thumb|300px|Corn vs Ethanol production in the United States
{{legend|#FFD932|Total corn production ([[Bushel|bushels]]) (left)}}
{{legend|B51700|Corn used for [[Ethanol fuel]] (bushels) (left)}}
{{legend-line|#313131 solid 3px|Percent of corn used for Ethanol (right)}}
]]
[[File:Blender fuels pump - East Lansing, MI.JPG|thumb|Blender fuels pump in 2012 selling the standard [[gasohol#E10 or less|E10]] ethanol blend together with [[common ethanol fuel mixtures#E15|E15]], E30 and [[E85]] in [[East Lansing, Michigan]]]]
[[File:Fuel ethanol production by state in 2016 (43142667775).png|thumb|upright=1.2|Ethanol fuel production by state]]
The [[United States]] became the world's largest producer of [[ethanol fuel]] in 2005. The U.S. produced 15.8 billion [[gallon|U.S. liquid gallons]] of [[ethanol]] fuel in 2019, and 13.9 billion [[gallon|U.S. liquid gallons]] (52.6 billion liters) in 2011,<ref name=RFAOutlook2012/><ref name="Annual Ethanol Production">{{Cite web|title=Annual Ethanol Production|url=https://ethanolrfa.org/statistics/annual-ethanol-production/|access-date=November 11, 2020|website=Renewable Fuels Association|language=en-US|archive-date=August 9, 2020|archive-url=https://web.archive.org/web/20200809114211/https://ethanolrfa.org/statistics/annual-ethanol-production/|url-status=dead}}</ref> an increase from 13.2 billion [[gallon|U.S. liquid gallons]] (49.2 billion liters) in 2010, and up from 1.63 billion gallons in 2000.<ref name=RFAProd2010/> [[Brazil]] and U.S. production accounted for 87.1% of global production in 2011.<ref name=RFAOutlook2012/> In the U.S, ethanol fuel is mainly used as an [[oxygenate]] in [[gasoline]] in the form of [[Common ethanol fuel mixtures#E10 or less|low-level blends]] up to 10 percent, and, increasingly, as [[E85]] fuel for [[flexible-fuel vehicle|flex-fuel vehicles]].<ref name=EthanolUse>{{cite web |url=http://www.afdc.energy.gov/afdc/ethanol/market.html |title=Ethanol Market Penetration|publisher=Alternative Fuels and Advanced Vehicles Data Center, [[US DOE]]|access-date=June 25, 2006}}</ref> The U.S. government subsidizes ethanol production.<ref>{{Cite journal |last1=Khanna |first1=Madhu |last2=Ando |first2=Amy W. |last3=Taheripour |first3=Farzad |date=2008 |title=Welfare Effects and Unintended Consequences of Ethanol Subsidies |url=https://www.jstor.org/stable/30225883 |journal=Review of Agricultural Economics |volume=30 |issue=3 |pages=411–421 |doi=10.1111/j.1467-9353.2008.00414.x |jstor=30225883 |issn=1058-7195}}</ref><ref>{{Cite journal |last1=Bielen |first1=David A. |last2=Newell |first2=Richard G. |last3=Pizer |first3=William A. |date=2018-05-01 |title=Who did the ethanol tax credit benefit? An event analysis of subsidy incidence |url=https://www.sciencedirect.com/science/article/pii/S0047272718300458 |journal=Journal of Public Economics |language=en |volume=161 |pages=1–14 |doi=10.1016/j.jpubeco.2018.03.005 |s2cid=155343802 |issn=0047-2727}}</ref>  

The ethanol market share in the U.S. gasoline supply grew by volume from just over 1 percent in 2000 to more than 3 percent in 2006 to 10 percent in 2011.<ref name=RFAOutlook2012>{{cite web|url=http://ethanolrfa.3cdn.net/d4ad995ffb7ae8fbfe_1vm62ypzd.pdf|title=Acelerating Industry Innovation - 2012 Ethanol Industry Outlook|author=Renewable Fuels Association|publisher=[[Renewable Fuels Association]]|date=March 6, 2012|access-date=May 6, 2012|archive-url=https://web.archive.org/web/20120514044111/http://ethanolrfa.3cdn.net/d4ad995ffb7ae8fbfe_1vm62ypzd.pdf|archive-date=May 14, 2012|url-status=dead}} ''See pp. 10''.</ref><ref name=RFA2011>{{cite web|url=http://www.ethanolrfa.org/page/-/2011%20RFA%20Ethanol%20Industry%20Outlook.pdf?nocdn=1 |title=2011 Ethanol Industry Outlook: Building Bridges to a More Sustainable Future |publisher=Renewable Fuels Association |year=2011 |access-date=April 30, 2011 |url-status=dead |archive-url=https://web.archive.org/web/20110928131808/http://www.ethanolrfa.org/page/-/2011%20RFA%20Ethanol%20Industry%20Outlook.pdf?nocdn=1 |archive-date=September 28, 2011 }}''See pages 2–3, 10–11, 19–20, and 26–27''.</ref><ref name=USDA0410>{{cite web|url=http://www.ers.usda.gov/topics/farm-economy/bioenergy/background.aspx|title=Bioenergy: Background – Ethanol|publisher=[[U.S. Department of Agriculture]]|date=April 10, 2010|access-date=September 16, 2010|archive-url=https://web.archive.org/web/20120818104458/http://www.ers.usda.gov/topics/farm-economy/bioenergy/background.aspx|archive-date=August 18, 2012|url-status=dead}}</ref> Domestic production capacity increased fifteen times after 1990, from 900 million US gallons to 1.63 billion US gal in 2000, to 13.5 billion US gallons in 2010.<ref name=RFA2011/><ref name=RFA2E>{{cite web |url=http://www.ethanolrfa.org/industry/statistics/#A|title=Historic U.S. fuel Ethanol Production| publisher=Renewable Fuels Association|access-date=June 25, 2006 |archive-url = https://web.archive.org/web/20060615233458/http://ethanolrfa.org/industry/statistics/#A |archive-date =June 15, 2006}}</ref> The [[Renewable Fuels Association]] reported 209 ethanol distilleries in operation located in 29 states in 2011.<ref name=RFAOutlook2012/>

By 2012 most cars on U.S. roads could run on blends of up to 10% ethanol([[Common ethanol fuel mixtures#E10 or less|E10]]), and manufacturers had begun producing vehicles designed for much higher percentages. However, the fuel systems of cars, trucks, and motorcycles sold before the ethanol mandate may suffer substantial damage from the use of 10% ethanol blends. Flexible-fuel cars, trucks, and minivans use gasoline/ethanol blends ranging from pure gasoline up to 85% ethanol ([[Common ethanol fuel mixtures#E85|E85]]). By early 2013 there were around 11 million E85-capable vehicles on U.S. roads.<ref name=FFV11m/><ref name=E15/> Regular use of E85 is low due to lack of fueling infrastructure, but is common in the [[Midwestern United States|Midwest]].<ref name=EERE08/><ref name=SusEthanol/> In January 2011 the [[U.S. Environmental Protection Agency]] (EPA) granted a waiver to allow up to 15% of ethanol blended with gasoline ([[Common ethanol fuel mixtures#E15|E15]]) to be sold only for cars and light pickup trucks with a [[model year]] of 2001 or later. The EPA waiver authorizes, but does not require stations to offer E15. Like the limitations suffered by sales of E85, commercialization of E15 is constrained by the lack of infrastructure as most fuel stations do not have enough pumps to offer the new E15 blend, few existing pumps are certified to dispense E15, and no dedicated tanks are readily available to store E15.<ref name=NYT1013/><ref name=USAToday1013/><ref name=NYT012111/>

Historically most U.S. ethanol has come from [[Maize|corn]], and the required electricity for many [[distillery|distilleries]] came mainly from [[coal]]. There is a debate  about ethanol's [[sustainability]] and environmental impact.<ref>{{Cite journal |last=Hill |first=Jason |date=2022-03-09 |title=The sobering truth about corn ethanol |journal=Proceedings of the National Academy of Sciences |volume=119 |issue=11 |pages=e2200997119 |doi=10.1073/pnas.2200997119|pmid=35263229 |pmc=8931354 |bibcode=2022PNAS..11900997H |issn=0027-8424}}</ref> The primary issues related to the large amount of [[arable land]] required for crops and ethanol production's impact on [[food vs. fuel|grain supply]], [[Indirect land use change impacts of biofuels|indirect land use change]] (ILUC) effects, as well as issues regarding its [[energy returned on energy invested|energy balance]] and [[carbon intensity]] considering its [[life cycle assessment|full life cycle]].<ref name="WorldBank">{{cite web|url=http://siteresources.worldbank.org/INTWDR2008/Resources/2795087-1192112387976/WDR08_05_Focus_B.pdf |title=Biofuels: The Promise and the Risks, in World Development Report 2008 |publisher=The World Bank|year=2008|pages= 70–71|access-date=May 4, 2008}}</ref><ref name="ARBproposal" /><ref name="Oxfam" /><ref name="Fargione08" /><ref name="Science08" /><ref>Youngquist, W. [[Geodestinies]], National Book company, Portland, OR, 499p.</ref>{{TOC limit|3}}

==History==
[[File:Gasoline with less than 10% 83 MIA 12 2008.jpg|right|200px|thumb|Typical label at the gas pumps warning drivers of ethanol content up to 10%, used as oxygenate additive instead of [[MTBE]]. [[Miami]], [[Florida]].]]
In 1826 [[Samuel Morey]] experimented with an [[internal combustion]] chemical mixture that used ethanol (combined with [[turpentine]] and ambient air then [[vaporized]]) as [[fuel]]. At the time, his discovery was overlooked, mostly due to the success of [[steam power]]. Ethanol fuel received little attention until 1860 when [[Nicholas Otto]] began experimenting with [[internal combustion engine]]s. In 1859, [[oil]] was found in [[Pennsylvania]], which decades later provided a new kind of fuel. A popular fuel in the U.S. before [[petroleum]] was a blend of alcohol and turpentine called "[[camphene]]", also known as "burning fluid".{{citation needed|date=November 2011}} The discovery of a ready supply of oil and unfavorable taxation on burning fluid made [[kerosene]] a more popular fuel.{{Citation needed|date=January 2021}}

In 1896, [[Henry Ford]] designed his first car, the "[[Ford Quadricycle|Quadricycle]]" to run on pure ethanol.<ref name="Ethanol"/> In 1908, the revolutionary [[Ford Model T]] was capable of running on [[gasoline]], [[ethanol (fuel)|ethanol]] or a combination.<ref name="Ethanol"/><ref>{{cite news|url=https://www.telegraph.co.uk/motoring/main.jhtml?xml=/motoring/2008/07/25/mnmodel125.xml|archive-url=https://archive.today/20120529160308/http://www.telegraph.co.uk/motoring/main.jhtml?xml=/motoring/2008/07/25/mnmodel125.xml|url-status=dead|archive-date=May 29, 2012|title= Ford Model T reaches 100|newspaper=[[The Daily Telegraph]]|date=July 25, 2008|access-date=August 11, 2008 | location=London | first=Andrew | last=English}}</ref><ref>{{cite web|url=http://journeytoforever.org/ethanol.html#ethintro|title= Ethanol: Introduction|publisher=Journey to Forever|access-date=August 11, 2008}}</ref> Ford continued to advocate for ethanol fuel even during the [[Prohibition in the United States|prohibition]], but lower prices caused gasoline to prevail.<ref name="Ethanol"/>
[[File:E10 warning 475 DC.JPG|thumb|left|Typical manufacture's warning placed in the fuel filler of U.S. vehicles regarding the capability of using up to E10, and warning against the use of blends between E20 and E85.]]
Gasoline containing up to 10% ethanol began a decades-long growth in the United States in the late 1970s. The demand for ethanol produced from [[field corn]] was spurred by the discovery that [[Methyl tert-butyl ether|methyl tertiary butyl ether (MTBE)]] was contaminating [[groundwater]].<ref name="Ethanol">{{Cite book|author1=Goettemoeller, Jeffrey |author2=Adrian Goettemoeller |title = Sustainable Ethanol: Biofuels, Biorefineries, Cellulosic Biomass, Flex-Fuel Vehicles, and Sustainable Farming for Energy Independence|year = 2007| publisher = Prairie Oak Publishing, Maryville, Missouri |page=42 | isbn = 978-0-9786293-0-4 }}</ref><ref>{{cite web|url=http://www.eia.doe.gov/pub/oil_gas/petroleum/feature_articles/2006/mtbe2006/mtbe2006.pdf|title=Eliminating MTBE in Gasoline in 2006|date=February 22, 2006|publisher=Environmental Information Administration|access-date=August 10, 2008|url-status=dead|archive-url=https://web.archive.org/web/20080822000011/http://www.eia.doe.gov/pub/oil_gas/petroleum/feature_articles/2006/mtbe2006/mtbe2006.pdf|archive-date=August 22, 2008}}</ref> MTBE's use as an oxygenate [[gasoline additive|additive]] was widespread due to mandates in the [[Clean Air Act (1990)|Clean Air Act]] amendments of 1992 to reduce [[carbon monoxide]] emissions. MTBE in gasoline had been banned in almost 20 states by 2006. Suppliers were concerned about potential litigation and a 2005 court decision denying legal protection for MTBE.{{citation needed|date=November 2011}} MTBE's fall from grace opened a new market for ethanol, its primary substitute.<ref name="Ethanol"/> Corn prices at the time were around [[US$]]2 a [[bushel]].{{citation needed|date=November 2011}} Farmers saw a new market and increased production. This demand shift took place at a time when [[Oil price increases since 2003|oil prices]] were rising.{{Citation needed|date=January 2021}}

The steep growth in twenty-first century ethanol consumption was driven by federal legislation aimed to reduce oil consumption and [[United States energy independence|enhance energy security]]. The [[Energy Policy Act of 2005]] required use of {{convert|7500000000|USgal|L|abbr=on}} of renewable fuel by 2012, and the [[Energy Independence and Security Act of 2007]] raised the standard, to {{convert|36000000000|USgal|L|abbr=on}} of annual renewable fuel use by 2022. Of this requirement, {{convert|21000000000|USgal|L|abbr=on}} had to be advanced [[biofuel]]s, defined as renewable fuels that reduce [[greenhouse gas emissions]] by at least 50%.<ref name=EIA2008>{{cite web|url=http://www.eia.doe.gov/ask/renewables_faqs.asp#ethanol_affect_fuel_economy|title=Question: How much ethanol is in gasoline and how does it affect fuel economy?|author=Energy Information Administration|date=June 4, 2010|publisher=EIA|access-date=July 26, 2010}}</ref><ref name=CBO2010/><ref name=DoEBiomass>{{cite web|url=http://www1.eere.energy.gov/biomass/federal_biomass.html|title=Federal Biomass Policy: Federal Legislation|publisher=[[U.S. Department of Energy]]|access-date=July 27, 2010}}</ref>

==Recent trends==
{| class="wikitable" style="text-align:right; float:right; margin-left:10px "
! colspan="4" style="text-align:center; background:#cfc;"|U.S. fuel ethanol<br />production and imports<br />(2000–2011)<ref name=RFAOutlook2012/><ref name=RFA1B>{{cite web|url=http://www.ethanolrfa.org/pages/statistics#B|title=Industry Statistics: Monthly U.S. Fuel Ethanol Production/Demand|publisher=Renewable Fuels Association|access-date=April 30, 2011|archive-date=September 24, 2015|archive-url=https://web.archive.org/web/20150924002634/http://www.ethanolrfa.org/pages/statistics/#B|url-status=dead}}</ref><ref name="Annual Ethanol Production"/><br /><small>(Millions of U.S. liquid gallons)</small>
|- style="background:#cfc;"
!Year
!Production
!Imports
!Demand
|-
|2000 ||1,630||n/a ||n/a
|-
|2001 ||1,770||n/a ||n/a
|-
|2002 ||2,130||46 ||2,085
|-
|2003 ||2,800||61 ||2,900
|-
|2004 ||3,400||161 ||3,530
|-
|2005 ||3,904||135 ||4,049
|-
|2006 ||4,855||653 || 5,377
|-
|2007 ||6,500 ||450 ||6,847
|-
|2008 ||9,000 ||556 ||9,637
|-
|2009||10,600 ||193 ||10,940
|-
|2010||13,298 ||10 ||13,184
|-
|2011||13,929||160||n/a<sup>(1)</sup>
|-
|2012
|13,218
|
|
|-
|2013
|13,293
|
|
|-
|2014
|14,313
|
|
|-
|2015
|14,807
|
|
|-
|2016
|15,413
|
|
|-
|2017
|15,936
|
|
|-
|2018
|16,091
|
|
|-
|2019
|15,776
|
|
|-
| colspan="4" style="text-align:left;"|<small>Note: Demand figures includes stocks change and<br />small exports in 2005.<br />(1) Exports in 2011 reached a record 1,100 billion gal.<ref name=RFAOutlook2012/></small>
|-
|colspan="4" style="text-align:center;"|[[File:Ethanol production and imports in the US.svg|thumb|250px|Graph of monthly production and net imports of fuel ethanol in the U.S. 1993–2012. Data from [http://www.eia.gov/totalenergy/data/monthly/#renewable EIA]]]
|}

The world's top ethanol fuel producer in 2010 was the United States with 13.2 billion U.S. gallons (49.95 billion liters) representing 57.5% of global production, followed by Brazil with 6.92 billion U.S. gallons (26.19 billion liters), and together both countries accounted for 88% of the world production of 22.95 billion U.S. gallons (86.85 billion liters).<ref name=RFAProd2010>{{cite web|url=http://www.ethanolrfa.org/pages/statistics#E|title=Industry Statistics: 2010 World Fuel Ethanol Production|publisher=Renewable Fuels Association|author=F.O. Lichts|access-date=April 30, 2011|archive-date=September 24, 2015|archive-url=https://web.archive.org/web/20150924002634/http://www.ethanolrfa.org/pages/statistics/#E|url-status=dead}}</ref> By December 2010 the U.S. ethanol production industry consisted of 204 plants operating in 29 states,<ref name=RFA2011/><ref name=RFA2E/> and 9 plants under construction or expansion, adding 560 million gallons of new capacity and bringing total U.S. installed capacity to 14.6 billion U.S. gallons (55.25 billion liters).<ref name=RFA2E/> At the end of 2010 over 90 percent of all gasoline sold in the U.S. was blended with ethanol.<ref name=RFA2011/>

===Production===

[[File:Maryland 4958 DC 03 2009.jpg|thumb|left|Most of the ethanol consumed in the US is in the form of low blends with gasoline up to 10%. Shown a fuel pump in [[Maryland]] selling mandatory [[Common ethanol fuel mixtures#E10|E10]].]]
Beginning in late 2008 and early 2009, the industry came under financial stress due to that year's economic crisis. Motorists drove less and gasoline prices dropped sharply, while bank financing shrank.<ref name="NYT0209">{{cite news |author=Clifford Krauss |date=February 11, 2009 |title=Ethanol, Just Recently a Savior, Is Struggling |newspaper=[[The New York Times]] |url=https://www.nytimes.com/2009/02/12/business/12ethanol.html |access-date=June 26, 2006}}</ref><ref name="OilShop">{{cite web |date=June 18, 2009 |title=Oil companies shop for discounted ethanol plants |url=http://news.moneycentral.msn.com/ticker/article.aspx?Feed=AP&Date=20090618&ID=10035949&Symbol=US:CVX |access-date=June 26, 2009 |publisher=MSN News}}{{dead link|date=April 2019|bot=medic}}{{cbignore|bot=medic}}</ref><ref name="E2T">{{cite web |author=Katie Fehrenbacher |date=November 17, 2008 |title=Financial Crisis Puts Aventine Ethanol Plant On Hold |url=http://earth2tech.com/2008/11/17/financial-crisis-puts-aventine-ethanol-plant-on-hold/ |access-date=June 26, 2009 |publisher=earth2tech}}</ref> As a result, some plants operated below capacity, several firms closed plants, others laid off staff, some firms went [[bankruptcy|bankrupt]], plant projects were suspended and market prices declined.<ref name=NYT0209/><ref name=OilShop/><ref name=E2T/> The [[Energy Information Administration]] raised concerns that the industry would not meet the legislated targets.<ref name=NYT0209/><ref>{{cite news |url=https://www.reuters.com/article/environmentNews/idUSTRE4BG4EQ20081217?feedType=RSS&feedName=environmentNews |title=U.S. will fail to meet biofuels mandate: EIA |work=Reuters |author=Timothy Gardner |date=December 17, 2008 |access-date=June 26, 2009}}</ref>

As of 2011, most of the U.S. car fleet was able to run on blends of up to 10% ethanol, and motor vehicle manufacturers produced vehicles designed to run on more concentrated blends. As of 2015, seven states – [[Missouri]], [[Minnesota]], [[Louisiana]], [[Montana]], [[Oregon]], [[Pennsylvania]], and [[Washington (U.S. state)|Washington]] – required ethanol to be blended with gasoline in motor fuels.<ref>{{cite web|url=http://www.greencarreports.com/news/1099149_state-laws-on-ethanol-in-gasoline-only-seven-states-require-e10-blend |title=State Laws on Ethanol in Gasoline: Only Seven States Require E10 Blend |date=July 17, 2015 |access-date=December 21, 2016 |url-status=live |archive-url=https://web.archive.org/web/20161222152708/http://www.greencarreports.com/news/1099149_state-laws-on-ethanol-in-gasoline-only-seven-states-require-e10-blend |archive-date=December 22, 2016 }}</ref> These states, particularly Minnesota, had more ethanol usage, and according to a source at Washington University, these states accumulated substantial environmental and economic benefits as a result.<!--what benefits?--><ref>{{cite web|url=http://law.wustl.edu/Journal/26/Bixby.pdf|title=The 2005 Energy Policy Act: Lessons on Getting Alternative Fuels to the Pump from Minnesota's Ethanol Regulations|publisher=[[Washington University Journal of Law & Policy]]|author=James W. Bixby|access-date=October 29, 2009|url-status=dead|archive-url=https://web.archive.org/web/20100603110355/http://www.law.wustl.edu/Journal/26/Bixby.pdf|archive-date=June 3, 2010}}</ref> Florida required ethanol blends as of the end of 2010,<ref>{{cite web|url=http://www.eere.energy.gov/afdc/progs/ind_state_laws.php/FL/ETH |title=Florida E85 Laws and Incentives |publisher=U.S. Department of Energy |date=March 11, 2008 |access-date=August 14, 2008 |url-status=dead |archive-url=https://web.archive.org/web/20080807124036/http://www.eere.energy.gov/afdc/progs/ind_state_laws.php/FL/ETH |archive-date=August 7, 2008 }}</ref> but has since repealed it. Many cities had separate ethanol requirements due to non-attainment of federal air quality standards.<ref>[https://www.npr.org/templates/story/story.php?storyId=17720583 3 states, many cities]</ref> In 2007, [[Portland, Oregon]], became the first U.S. city to require all gasoline sold within city limits to contain at least 10% ethanol.<ref name=cleanedge.com>[http://www.cleanedge.com/book/Introduction_The_Clean_Tech_Revolution.pdf Introduction: The Clean Tech Opportunity] {{webarchive |url=https://web.archive.org/web/20070716043717/http://www.cleanedge.com/book/Introduction_The_Clean_Tech_Revolution.pdf |date=July 16, 2007 }} p. 3.</ref><ref>[http://postcarboncities.net/node/192 Portland requires stations to sell biofuels, giving farmers a boost|Post Carbon Cities] {{webarchive |url=https://web.archive.org/web/20160306030835/http://postcarboncities.net/node/192 |date=March 6, 2016 }}</ref> Chicago has proposed the idea of mandating E15 in the city limits, while some area gas stations have already begun offering it.<ref>{{cite web|url=https://www.chicagotribune.com/suburbs/daily-southtown/news/ct-sta-new-ethanol-fuel-st-0629-20160628-story.html |title=Thorntons gas stations introducing new ethanol fuel |website=[[Chicago Tribune]] |date=June 29, 2016 |access-date=December 21, 2016 |url-status=live |archive-url=https://web.archive.org/web/20161222082319/http://www.chicagotribune.com/suburbs/daily-southtown/news/ct-sta-new-ethanol-fuel-st-0629-20160628-story.html |archive-date=December 22, 2016 }}</ref><ref>{{cite web|url=https://www.chicagotribune.com/news/82227312-132.html |title=Ald. Ed Burke on E15 gasoline proposal |website=[[Chicago Tribune]] |date=December 8, 2014 |access-date=December 21, 2016 |url-status=live |archive-url=https://web.archive.org/web/20161222083304/http://www.chicagotribune.com/news/82227312-132.html |archive-date=December 22, 2016 }}</ref>

Expanding ethanol (and [[biodiesel]]) industries provided jobs in plant construction, operations, and maintenance, mostly in rural communities. According to RFA the ethanol industry created almost 154,000 U.S. jobs in 2005, boosting household income by $5.7 billion. It also contributed about $3.5 billion in federal, state and local tax revenues.<ref name="images1.americanprogress">Worldwatch Institute and Center for American Progress (2006).[http://images1.americanprogress.org/il80web20037/americanenergynow/AmericanEnergy.pdf ''American Energy: The Renewable Path to Energy Security''] {{webarchive|url=https://web.archive.org/web/20160603103041/http://images1.americanprogress.org/il80web20037/americanenergynow/AmericanEnergy.pdf|date=June 3, 2016}}</ref>

The return on investment (ROI) to upgrade a service station to sell E15 is quick given today's markets. Given ethanol's discount to gasoline and the current value of RINs, retailers offering mid-level ethanol blends like E15 can quickly recoup their investments in infrastructure. Federal, state and local incentives and grant programs are available in most areas, and would further help reduce the cost of equipment and installation. E15 is a higher octane fuel, it is currently available in 29 states at retail fueling stations. E15 was approved for use in model year 2001 and newer cars, light-duty trucks, medium-duty passenger vehicles (SUVs), and all flex-fuel vehicles (FFVs) by the U.S. Environmental Protection Agency (EPA) in 2012.{{Citation needed|date=January 2021}}

===E85 vehicles===
{{See also|Flexible-fuel vehicles in the United States}} 
[[File:Three US E85 flex fuel badges Ford GM Chrysler copy.jpg|thumb|left|Typical labeling used in the US to identifyE85 flexible-fuel vehicles. Top left: a small sticker in the back of the fuel filler door. Bottom left: the bright yellow gas cap used in newer models. E85 Flexfuel badging used in newer models from [[Chrysler]] (top right), [[Ford Motor Company|Ford]] (middle right) and GM (bottom right).]]
[[File:E85 fuel pump 7562 DCA 09 2009.jpg|thumb|E85 fuel dispenser at a regular gasoline station, [[Washington, D.C.]]]]
[[Ford Motor Company|Ford]], [[Chrysler]], and [[General Motors|GM]] are among many automobile companies that sell flexible-fuel vehicles that can run blends ranging from pure gasoline to 85% ethanol ([[E85]]), and beginning in 2008 almost any type of automobile and [[light duty vehicle]] was available with the flex-fuel option, including [[sedan (car)|sedan]]s, [[van]]s, [[sport utility vehicle|SUV]]s and [[pickup truck]]s. By early 2013, about 11 million E85 flex-fuel cars and light trucks were in operation,<ref name=FFV11m>{{cite web|url=http://domesticfuel.com/2013/02/28/new-ethanol-video-released/|title=New Ethanol Video Released|author=Renewable Fuels Association|author-link=Renewable Fuels Association|work=DomesticFuel.com|date=March 28, 2013|access-date=April 10, 2013}}</ref><ref name=E15/> though actual use of E85 fuel was limited, because the ethanol fueling infrastructure was limited.<ref name=E85stat>{{cite web|url=http://www.e85fuel.com/news/080808fyi.htm|title=New E85 Stations|publisher=NEVC FYI Newsletter (Vol 14 no. 13)|author=National Ethanol Vehicle Coalition|date=August 8, 2008|access-date=August 19, 2008|archive-url=https://web.archive.org/web/20081010013636/http://www.e85fuel.com/news/080808fyi.htm|archive-date=October 10, 2008|url-status=dead}} ''For a complete and updated listing, go to www.e85refueling.com''</ref>

As of 2005, 68% of American flex-fuel car owners were not aware they owned an E85 flex.<ref name=EERE08>{{cite web|url=http://www.eere.energy.gov/afdc/vehicles/flexible_fuel.html| title=Alternative and Advanced Vehicles: Flexible Fuel Vehicles|author=National Renewable Energy Laboratory USDoE|publisher=Alternative Fuels and Advanced Vehicles Data Center|date=September 17, 2007|access-date=August 19, 2008 }}</ref><ref name="SusEthanol">{{Cite book|author1=Goettemoeller, Jeffrey |author2=Adrian Goettemoeller |title = Sustainable Ethanol: Biofuels, Biorefineries, Cellulosic Biomass, Flex-Fuel Vehicles, and Sustainable Farming for Energy Independence|year = 2007| publisher = Prairie Oak Publishing, Maryville, Missouri |pages=56–61 | isbn = 978-0-9786293-0-4 }}</ref> Flex and non-flex vehicles looked the same. There was no price difference. American automakers did not label these vehicles.<ref name="SusEthanol"/><ref name="Apollo">{{Cite book|author1 = Inslee, Jay|author2 = Bracken Hendricks|title = Apollo's Fire|year = 2007|pages = [https://archive.org/details/apollosfireignit00insl/page/153 153]–155, 160–161|publisher = Island Press, Washington, D.C.|isbn = 978-1-59726-175-3|url = https://archive.org/details/apollosfireignit00insl|url-access = registration}} ''See Chapter 6. Homegrown Energy''</ref> In contrast, all Brazilian automakers clearly labeled [[flexible-fuel vehicles in Brazil|FFVs]] with text that was some variant of the word Flex. Beginning in 2007 many new FFV models in the US featured a yellow gas cap to remind drivers of the E85 capabilities.<ref name="NHTSA">{{cite news|url=https://www.usatoday.com/money/autos/environment/2007-05-05-ethanolvehicles_N.htm| title= 'Flex-fuel' vehicles touted|newspaper = USA Today|author=Ken Thomas|date=May 7, 2007|access-date= September 15, 2008 }}</ref><ref name="YellowCap">{{cite web |url=http://alternativefuels.about.com/od/vehiclebuyingguide/ig/Alt-fuels---New-York-Auto-Show/Yellow-E85-gas-cap.htm |title=Yellow E85 gas cap |publisher=About.com: Hybrid Cars & Alt Fuels |author1=Christine Gable |author2=Scott Gable |access-date=September 18, 2008 |archive-url=https://web.archive.org/web/20081005054544/http://alternativefuels.about.com/od/vehiclebuyingguide/ig/Alt-fuels---New-York-Auto-Show/Yellow-E85-gas-cap.htm |archive-date=October 5, 2008 |url-status=dead }}</ref> As of 2008, GM badged its vehicles with the text "Flexfuel/E85 Ethanol".<ref>{{cite web|url=http://alternativefuels.about.com/od/2008flexfuelreviews/fr/08SilveradoFFV_2.htm|title=2008 Chevrolet Silverado 1500 4WD LT2 flex-fuel truck test drive|publisher=About.com: Hybrid Cars & Alt Fuels|author1=Christine Gable|author2=Scott Gable|access-date=October 3, 2008|archive-date=August 7, 2011|archive-url=https://web.archive.org/web/20110807191620/http://alternativefuels.about.com/od/2008flexfuelreviews/fr/08SilveradoFFV_2.htm|url-status=dead}}</ref><ref>{{cite web |url=http://alternativefuels.about.com/od/flexfuelffvreviews/fr/2007Suburban_2.htm |title=2007 Chevrolet Suburban 4WD 1500 LT test drive |publisher=About.com: Hybrid Cars & Alt Fuels |author1=Christine Gable |author2=Scott Gable |access-date=October 3, 2008 |archive-date=July 24, 2011 |archive-url=https://web.archive.org/web/20110724235247/http://alternativefuels.about.com/od/flexfuelffvreviews/fr/2007Suburban_2.htm |url-status=dead }}</ref> Nevertheless, the [[U.S. Department of Energy]] (DOE) estimated that in 2009 only 504,297 flex-fuel vehicles were regularly fueled with E85, and these were primarily fleet-operated vehicles.<ref name=USeDataBook>{{cite web|url=http://cta.ornl.gov/data/tedb30/Edition30_Full_Doc.pdf |title=Transportation Energy Data Book: Edition 30 |author1=Stacy C. Davis |author2=Susan W. Diegel |author3=Robert G. Boundy |publisher=Office of Energy Efficiency and Renewable Energy, U.S. Department of Energy |date=June 2011 |access-date=August 28, 2011 |url-status=dead |archive-url=https://web.archive.org/web/20110928135644/http://cta.ornl.gov/data/tedb30/Edition30_Full_Doc.pdf |archive-date=September 28, 2011 }} See Table 6.1 pp. 6–3.</ref> As a result, only 712 million gallons were used for E85, representing just 1% of that year's ethanol consumption.<ref name=USeDataBook2>{{Cite journal| author = Davis|title = op. cit| year = 2011| pages = 2–6|display-authors=etal}} ''See Table 2.4''</ref>

During the decade following 2000, E85 vehicles became increasingly common in the [[Midwest]], where corn was a major [[agriculture|crop]].{{Citation needed|date=January 2021}}

Fueling infrastructure has been a major restriction hampering E85 sales.<ref name="E85stat"/> {{As of|2013|03}}, there were 3,028 fueling stations selling E85 in the U.S.<ref name=E85prices>{{cite web|url=http://www.e85prices.com/ |title=Ethanol Production Mandates |work=E85Prices.com |access-date=April 11, 2013 |url-status=dead |archive-url=https://web.archive.org/web/20140701095550/http://www.e85prices.com/ |archive-date=July 1, 2014 }}</ref> Most stations were in the [[Corn Belt]] states. As of 2008 the leading state was Minnesota with 353 stations, followed by [[Illinois]] with 181, and [[Wisconsin]] with 114. About another 200 stations that dispensed ethanol were restricted to city, state and federal government vehicles.<ref name="E85stat"/>

<gallery>
Chevrolet Impala FlexFuel 34 MIA 12 2008 with logo.jpg|E85 [[flexfuel]] [[Chevrolet Impala]] LT 2009.
Chevrolet HRR FlexFuel 70 MIA 12 2008 with logo.jpg|E85 [[flexfuel]] [[Chevrolet HHR]]
Van Ford E-250 Flex Fuel DCA 7547.jpg|E85 flexfuel [[Ford E-Series|Ford E-250]].
Ford Escape Flex 7893 VA 11 09 with badge.jpg|E85 [[flexfuel]] [[Ford Escape]]
</gallery>

===E15 blend===

[[File:E15 warning sticker.JPG|thumb|left|[[common ethanol fuel mixtures#E15|E15]] warning sticker required to be displayed in all fuel dispensers selling that blend in the U.S.]]
[[File:2012 Camry fuel filler cap 04 2014 141619.jpg|thumb|left|2012 [[Toyota Camry (XV50)#Camry Hybrid|Toyota Camry Hybrid]] fuel filler cap showing a warning regarding the maximum ethanol blend allowed by the carmaker, up to E10 gasoline. The warning label indicates that ethanol blends between E15 to E85 shall not be used in this vehicle.]]

In March 2009 Growth Energy, a lobbying group for the ethanol industry, formally requested the [[U.S. Environmental Protection Agency]] (EPA) to allow the ethanol content in gasoline to be increased to 15%, from 10%.<ref>{{cite news|url=http://wheels.blogs.nytimes.com/2010/06/18/e-p-a-delays-ruling-on-increasing-ethanol-content-in-gasoline/|title=E.P.A. Delays Ruling on Increasing Ethanol Content in Gasoline|newspaper=The New York Times|date=June 18, 2010|access-date=June 19, 2010 |first=Christopher | last=Jensen}}</ref> In October 2010, the EPA granted a waiver to allow up to 15% blends to be sold for cars and trucks with a model year of 2007 or later, representing about 15% of vehicles on the roads.<ref name=NYT1013>{{cite news|url=https://www.nytimes.com/2010/10/14/business/energy-environment/14ethanol.html?_r=1&emc=eta1|title=A Bit More Ethanol in the Gas Tank|author=Matthew L. Wald|work=The New York Times|date=October 13, 2010|access-date=October 14, 2010}}</ref><ref name=USAToday1013>{{cite news|url=http://content.usatoday.com/communities/driveon/post/2010/10/epa-to-allow-15-ethanol-in-gasoline-up-from-10-now-/1?POE=click-refer|title=EPA allows 15% ethanol in gasoline, but only for late-model cars
|author=Fred Meier|work=USA Today|date=October 13, 2010|access-date=October 14, 2010}}</ref> In January 2011 the waiver was expanded to authorize use of E15 to include model year 2001 through 2006 passenger vehicles. The EPA also decided not to grant any waiver for E15 use in any motorcycles, heavy-duty vehicles, or non-road engines because current testing data does not support such a waiver. According to the [[Renewable Fuels Association]] the E15 waivers now cover 62% of vehicles on the road in the country.<ref name=NYT012111>{{cite news|url=https://www.nytimes.com/2011/01/22/business/energy-environment/22ethanol.html?scp=4&sq=EPA%20E15&st=cse|title=E.P.A. Approves Use of More Ethanol in Gasoline|author=Matthew L. Wald|date=January 21, 2011|access-date=February 26, 2011|work=The New York Times}}</ref><ref>{{cite web|url=http://www.greencarcongress.com/2011/01/e15-20110121.html#tp|title=US EPA extends E15 fuel waiver to MY 2001&ndash;2006 light-duty vehicles|publisher=[[Green Car Congress]]|date=January 21, 2011|access-date=January 26, 2011}}</ref> In December 2010 several groups, including the [[Alliance of Automobile Manufacturers]], the [[American Petroleum Institute]], the [[Association of International Automobile Manufacturers]], the National Marine Manufacturers Association, the Outdoor Power Equipment Institute, and the [[Grocery Manufacturers Association]], filed suit against the EPA.<ref>{{cite news|url=http://green.blogs.nytimes.com/2010/12/20/engine-makers-sue-to-block-e15-fuel/?emc=eta1 |title=Engine Makers Sue to Block E15 Fuel|author=Matthew L. Wald|work=The New York Times |date=December 20, 2010|access-date=August 18, 2012}}</ref> In August 2012 the federal appeals court rejected the suit against the EPA ruling that the groups did not have legal standing to challenge EPA's decision to issue the waiver for E15.<ref name=DTNews0812>{{cite news|url=http://www.detroitnews.com/article/20120817/AUTO01/208170431 |title=U.S. court rejects auto industry challenge to E15 |author=David Shepardson |work=[[The Detroit News]] |date=August 17, 2012 |access-date=August 18, 2012 |url-status=dead |archive-url=https://web.archive.org/web/20120818032725/http://www.detroitnews.com/article/20120817/AUTO01/208170431 |archive-date=August 18, 2012 }}</ref><ref>{{cite news|url=https://www.bloomberg.com/news/2012-08-17/epa-defeats-challenge-to-higher-ethanol-levels-in-fuel.html|title=EPA Defeats Challenge To Higher Ethanol Levels In Fuel |author=Sara Forden |work=Bloomberg News|date=August 17, 2012|access-date=August 18, 2012}}</ref> In June 2013 the [[U.S. Supreme Court]] declined to hear an appeal from industry groups opposed to the EPA ruling about E15 and let the 2012 federal appeals court ruling stand.<ref name=DT062013>{{cite news|url=http://www.detroitnews.com/article/20130624/AUTO01/306240093/1148/auto01/Court-declines-hear-challenge-EPA-s-stance-E15-gasoline |archive-url=https://archive.today/20130628030631/http://www.detroitnews.com/article/20130624/AUTO01/306240093/1148/auto01/Court-declines-hear-challenge-EPA-s-stance-E15-gasoline |url-status=dead |archive-date=June 28, 2013 |title=Court declines to hear challenge to EPA's stance on E15 gasoline |author=David Sheparson |work=[[The Detroit News]] |date=June 24, 2013 |access-date=June 25, 2013 }}</ref>

According to a survey conducted by the [[American Automobile Association]] (AAA) in 2012, only about 12 million out of the more than 240 million light-duty vehicles on the U.S. roads in 2012 are approved by manufacturers are fully compliant with E15 gasoline. According with the Association, [[BMW]], [[Chrysler]], [[Nissan]], [[Toyota]], and [[Volkswagen]] warned that their warranties will not cover E15-related damage.<ref name=AAAE15/> Despite the controversy, in order to adjust to EPA regulations, 2012 and 2013 [[model year]] vehicles manufactured by [[General Motors]] can use fuel containing up to 15 percent ethanol, as indicated in the vehicle owners' manuals. However, the carmaker warned that for model year 2011 or earlier vehicles, they "strongly recommend that GM customers refer to their owners manuals for the proper fuel designation for their vehicles." [[Ford Motor Company]] also is manufacturing all of its 2013 vehicles E15 compatible, including [[hybrid electric]]s and vehicles with [[Ford EcoBoost engine|Ecoboost engines]].<ref name=E15>{{cite web|url=http://ethanolproducer.com/articles/9195/gm-ford-announce-e15-compatibility-with-new-models|title=GM, Ford announce E15 compatibility with new models|author=Susanne Retka Schill|work=Ethanol Producer Magazine|date=October 17, 2012|access-date=August 26, 2015}}</ref> Also [[Porsche]]s built since 2001 are approved by its manufacturer to use E15.<ref name=AAAE15>{{cite web|url=http://newsroom.aaa.com/2012/11/new-e15-gasoline-may-damage-vehicles-and-cause-consumer-confusion/|title=New E15 Gasoline May Damage Vehicles and Cause Consumer Confusion|author=Michael Green|publisher=[[American Automobile Association]]|date=November 30, 2012|access-date=August 26, 2015}}</ref> Volkswagen announced that for the 2014 model year, its entire lineup will be E15 capable.<ref>{{cite web|url=http://www.greencarcongress.com/2013/07/vw-20130714.html|title=Volkswagen of America bringing in downsized 1.8L EA888 engine to displace 2.5L; all vehicles E15 capable|author=VW US Media Room|publisher=[[Green Car Congress]]|date=July 14, 2013|access-date=July 14, 2013}}</ref> [[Fiat Chrysler Automobiles]] announced in August 2015 that all 2016 model year [[Chrysler (division)|Chrysler]]/[[Fiat Automobiles|Fiat]], [[Jeep]], [[Dodge]] and [[Ram Trucks|Ram]] vehicles will be E15 compatible.<ref>{{cite web|url=http://www.greencarcongress.com/2015/08/20150818-fca.html|title=FCA approving use of E15 in MY 2016 vehicles|publisher=[[Green Car Congress]]|date=August 18, 2015|access-date=August 25, 2015}}</ref>

Despite EPA's waiver, there is a practical barrier to the commercialization of the higher blend due to the lack of infrastructure, similar to the limitations suffered by sales of [[E85]], as most fuel stations do not have enough pumps to offer the new blend, few existing pumps are certified to dispense E15, and there are no dedicated tanks readily available to store E15.<ref name=NYT1013/><ref name=USAToday1013/> In July 2012 a fueling station in [[Lawrence, Kansas]] became the first in the U.S. to sell the E15 blend. The fuel is sold through a blender pump that allows customers to choose between E10, E15, E30 or E85, with the latter blends sold only to [[flexible-fuel vehicle]]s.<ref>{{cite news|url=https://www.nytimes.com/2012/07/12/business/energy-environment/at-kansas-station-e15-fuel-reaches-the-masses.html?_r=1&ref=automobiles |title=In Kansas, Stronger Mix of Ethanol |author=Matthew L. Wald|work=The New York Times|date=July 11, 2012|access-date=August 18, 2012}}</ref> This station was followed by a Marathon fueling station in [[East Lansing, Michigan]].{{citation needed|date=October 2012}} {{As of|2013|06}}, there are about 24 fueling stations selling E15 out of 180,000 stations operating across the U.S.<ref name=DT062013/>

{{As of|2012|11}}, sales of E15 are not authorized in California, and according to the [[California Air Resources Board]] (CARB), the blend is still awaiting approval, and in a public statement the agency said that "it would take several years to complete the vehicle testing and rule development necessary to introduce a new transportation fuel into California's market."<ref>{{cite web|url=http://green.autoblog.com/2012/11/14/carb-it-will-take-years-for-california-to-decide-on-e15/|title=CARB: It will take years for California to decide on E15 |author=Jon LeSage|publisher=[[Autoblog Green]]|date=November 14, 2012|access-date=November 15, 2012}}</ref>

{{Clear}}

===Legislation and regulations===
[[File:President Trump in Iowa (48051796596).jpg|thumb|US President [[Donald Trump]] signs a 2019 executive order permitting the sale of 15% ethanol fuel year-round]]

The [[Energy Independence and Security Act of 2007]], directed DOE to assess the feasibility of using intermediate [[gasohol|ethanol blends]] in the existing vehicle fleet.<ref name="NRELE15E20"/> The [[National Renewable Energy Laboratory]] (NREL) evaluated the potential impacts on legacy vehicles and other engines.<ref name="NRELE15E20"/> In a preliminary report released in October 2008, NREL described the effects of E10, E15 and [[Common ethanol fuel mixtures#E20, E25|E20]] on tailpipe and evaporative emissions, catalyst and engine durability, vehicle driveability, engine operability, and vehicle and engine materials.<ref name="NRELE15E20"/><ref name="GreenCarE15">{{cite web|url=http://www.greencarcongress.com/2008/10/preliminary-tes.html |title=Preliminary Test Report Shows No Significant Change in Vehicle Emissions from Intermediate Ethanol Blends |publisher=Green Car Congress |date=October 7, 2008|access-date=October 19, 2008}}</ref> This preliminary report found that none of the vehicles displayed a malfunction indicator light; no fuel filter plugging symptoms were observed; no cold start problems were observed at {{Convert|24|C|F|lk=on}} and {{Convert|10|C}} under laboratory conditions; and all test vehicles exhibited a loss in fuel economy proportional to ethanol's lower energy density. For example, E20 reduced average fuel economy by 7.7% when compared to gas-only (E0) test vehicles.<ref name="NRELE15E20">{{cite web|url=http://feerc.ornl.gov/publications/Int_blends_Rpt_1.pdf |title=Effects of Intermediate Ethanol Blends on Legacy Vehicles and Small Non-Road Engines, Report 1 |author1=Brian West |author2=Keith Knoll |author3=Wendy Clark |author4=Ronald Graves |author5=John Orban |author6=Steve Przesmitzki |author7=Timothy Theiss |publisher=[[Oak Ridge National Laboratory]] and National Renewable Energy Laboratory |year=2008 |access-date=October 19, 2008 |url-status=dead |archive-url=https://web.archive.org/web/20081217073219/http://feerc.ornl.gov/publications/Int_blends_Rpt_1.pdf |archive-date=December 17, 2008 }} NREL/TP-540-43543, ORNL/TM-2008/117</ref>

The [[Obama Administration]] set the goal of installing 10,000 blender pumps nationwide by 2015. These pumps can dispense multiple blends including E85, E50, E30 and E20 that can be used by E85 vehicles. The [[US Department of Agriculture]] (USDA) issued a rule in May 2011 to include flexible fuel pumps in the [[Rural Energy for America Program]] (REAP). This ruling provided financial assistance, via grants and loan guarantees, to fuel station owners to install E85 and blender pumps.<ref>{{cite web|url=http://www.greencarcongress.com/2011/04/usda-issues-rule-to-provide-incentives-to-install-blender-pumps.html|title=USDA issues rule to provide incentives to install blender pumps|publisher=[[Green Car Congress]]|date=April 8, 2011|access-date=May 11, 2011}}</ref><ref>{{cite news|url=http://content.usatoday.com/communities/greenhouse/post/2011/04/us-funds-e-85-flex-fuel-pumps/1?sms_ss=email&at_xt=4dcaa3c3bd1fb265%2C0|title=USDA offers incentives to boost E-85 flex fuel use|author=Wendy Koch|work=[[USA Today]]|date=April 8, 2011|access-date=May 11, 2011}}</ref>

In May 2011 the [[Open Fuel Standard Act of 2011|Open Fuel Standard Act]] (OFS) was introduced to Congress with bipartisan support. The bill required that 50 percent of automobiles made in 2014, 80 percent in 2016, and 95 percent in 2017, be manufactured and warrantied to operate on non-petroleum-based fuels, which included existing technologies such as flex-fuel, [[natural gas vehicle|natural gas]], [[hydrogen vehicle|hydrogen]], [[biodiesel]], [[plug-in electric vehicle|plug-in electric]] and [[fuel cell vehicle|fuel cell]]. Considering the rapid adoption of [[flexible-fuel vehicles in Brazil]] and the fact that the cost of making flex-fuel vehicles was approximately $100 per car, the bill's primary objective was to promote a massive adoption of flex-fuel vehicles capable of running on ethanol or [[methanol]] fuel.<ref>{{cite web|url=http://green.autoblog.com/2011/05/05/house-members-introduce-technology-neutral-open-fuel-standard-ac/ |title=House members introduce technology-neutral Open Fuel Standard Act |publisher=[[AutoblogGreen]]|author=Eric Loveday|date=May 5, 2011|access-date=May 5, 2011}}</ref><ref>{{cite web|url=http://www.biofuelsjournal.com/articles/Bipartisan_Group_Introduces_Open_Fuel_Standard_Act-108547.html|title=Bipartisan Group Introduces Open Fuel Standard Act|publisher=Biofuels Journal|date=May 4, 2011|access-date=May 5, 2011|url-status=dead|archive-url=https://web.archive.org/web/20110910154859/http://www.biofuelsjournal.com/articles/Bipartisan_Group_Introduces_Open_Fuel_Standard_Act-108547.html|archive-date=September 10, 2011}}</ref><ref>{{cite news|url=http://www.washingtontimes.com/news/2010/jul/2/open-standards-for-auto-fuel/?page=1|title=ZUBRIN: Open standards for auto fuel|work=[[The Washington Times]]|author=Robert Zubrin|date=July 2, 2010|access-date=May 5, 2011}} A similar bill has been presented in previous Congress sessions with the same objective.</ref>

In November 2013, the Environmental Protection Agency opened for public comment its proposal to reduce the amount of ethanol required in the US gasoline supply as mandated by the [[Energy Independence and Security Act of 2007]]. The agency cited problems with increasing the blend of ethanol above 10%. This limit, known as the "blend wall", refers to the practical difficulty in incorporating increasing amounts of ethanol into the transportation fuel supply at volumes exceeding those achieved by the sale of nearly all gasoline as E10.<ref>{{cite news|url=http://www.epa.gov/otaq/fuels/renewablefuels/documents/420f13048.pdf|title=EPA Proposes 2014 Renewable Fuel Standards, 2015 Biomass-Based Diesel Volume|author=EPA|publisher=U.S. Environmental Protection Agency (EPA)|access-date=November 24, 2013
}}</ref><ref>{{cite news|url=https://www.nytimes.com/2013/11/16/us/for-first-time-epa-proposes-reducing-ethanol-requirement-for-gas-mix.html|title=For First Time, E.P.A. Proposes Reducing Ethanol Requirement for Gas Mix|author=Matthew L. Wald|work=The New York Times|date=November 15, 2013|access-date=November 24, 2013}}</ref>

===Contractual restrictions===
Gasoline distribution contracts in the United States generally have provisions that make offering E15 and E85 difficult, expensive, or even impossible. Such provisions include requirements that no E85 be sold under the gas station canopy, labeling requirements, minimum sales volumes, and exclusivity provisions. Penalties for breach are severe and often allow immediate termination of the agreement, cutting off supplies to retailers. Repayment of franchise royalties and other incentives is often required.<ref name="farmer">{{cite web |url=http://www.wisfarmer.com/news/headlines/rfa-report-card-offers-failing-grades-to-big-oil-fuel-chains-b99307702z1-266378091.html |title=RFA report card offers failing grades to big oil fuel chains |access-date=July 25, 2016 |url-status=dead |archive-url=https://web.archive.org/web/20160304032548/http://www.wisfarmer.com/news/headlines/rfa-report-card-offers-failing-grades-to-big-oil-fuel-chains-b99307702z1-266378091.html |archive-date=March 4, 2016 }}</ref>

==Energy security==
[[File:Ethanol plant.jpg|thumb|Ethanol fuel plant in [[West Burlington, Iowa]].]] 
One rationale for ethanol production in the U.S. is increased [[energy security]], from shifting supply from oil imports to domestic sources.<ref name=CBO2010/><ref>{{cite web|url=http://ethanol.org |title=Home &#124; American Coalition for Ethanol |access-date=June 2, 2008 |url-status=live |archive-url=https://web.archive.org/web/20161118030501/https://ethanol.org/ |archive-date=November 18, 2016 }} [{{cite web|url=http://ethanol.org |title=Home &#124; American Coalition for Ethanol |access-date=June 2, 2008 |url-status=live |archive-url=https://web.archive.org/web/20161118030501/https://ethanol.org/ |archive-date=November 18, 2016 }}/pdf/contentmgmt/Energy_Security_Issue_Brief.pdf Energy Security] {{cite web|url=http://ethanol.org/pdf/contentmgmt/Energy_Security_Issue_Brief.pdf |title=Archived copy |access-date=August 27, 2011 |url-status=dead |archive-url=https://www.webcitation.org/678jvRqVo?url=http://ethanol.org/pdf/contentmgmt/Energy_Security_Issue_Brief.pdf |archive-date=April 23, 2012 }}</ref> Ethanol production requires significant energy, and current U.S. production derives most of that energy from domestic coal, natural gas and other non-oil sources.<ref>{{cite web|url=http://www.ethanol.org |title=Home &#124; American Coalition for Ethanol |access-date=October 6, 2007 |url-status=live |archive-url=https://web.archive.org/web/20161118030501/https://ethanol.org/ |archive-date=November 18, 2016 }} [{{cite web|url=http://www.ethanol.org |title=Home &#124; American Coalition for Ethanol |access-date=October 6, 2007 |url-status=live |archive-url=https://web.archive.org/web/20161118030501/https://ethanol.org/ |archive-date=November 18, 2016 }}/pdf/contentmgmt/Science_Journal_January_2006.pdf Ethanol Can Contribute to Energy and Environmental Goals] {{cite web|url=http://www.ethanol.org/pdf/contentmgmt/Science_Journal_January_2006.pdf |title=Archived copy |access-date=August 27, 2011 |url-status=dead |archive-url=https://www.webcitation.org/678jvRFKm?url=http://www.ethanol.org/pdf/contentmgmt/Science_Journal_January_2006.pdf |archive-date=April 23, 2012 }}</ref> Because in 2006, 66% of U.S. oil consumption was imported, compared to a net surplus of coal and just 16% of natural gas (2006 figures),<ref>{{cite web|url=http://www.eia.doe.gov |title=U.S. Energy Information Administration (EIA) |access-date=April 28, 2011 |url-status=live |archive-url=https://web.archive.org/web/20080821085349/http://www.eia.doe.gov/ |archive-date=August 21, 2008 }} [{{cite web|url=http://www.eia.doe.gov |title=U.S. Energy Information Administration (EIA) |access-date=April 28, 2011 |url-status=live |archive-url=https://web.archive.org/web/20080821085349/http://www.eia.doe.gov/ |archive-date=August 21, 2008 }}/neic/brochure/infocard01.htm Energy INFOcard]</ref> the displacement of oil-based fuels to ethanol produced a net shift from foreign to domestic U.S. energy sources.{{Citation needed|date=January 2021}}

==Effect on gasoline prices==
The effect of ethanol use on gasoline prices is the source of conflicting opinion from economic studies, further complicated by the non-market forces of tax credits, met and unmet government quotas, and the dramatic recent increase in domestic oil production.<ref>{{cite web |url=http://www.eia.gov/dnav/pet/hist/LeafHandler.ashx?n%3DPET%26s%3DMCRFPUS1%26f%3DA |title=U.S. Field Production of Crude Oil (Thousand Barrels) |access-date=August 22, 2014 |url-status=dead |archive-url=https://web.archive.org/web/20161204010225/http://www.eia.gov/dnav/pet/hist/LeafHandler.ashx?n=PET&s=MCRFPUS1&f=A |archive-date=December 4, 2016 }}</ref> According to a 2012 [[Massachusetts Institute of Technology]] analysis, ethanol, and biofuel in general, does not materially influence the price of gasoline,<ref>{{cite web|url=http://www.scientificamerican.com/article/ethanol-fails-lower-gas-prices-study-finds/ |title=Ethanol Fails to Lower Gas Prices, Study Finds |website=[[Scientific American]] |date=July 12, 2012| access-date=May 15, 2014 |url-status=live |archive-url=https://web.archive.org/web/20161011024949/https://www.scientificamerican.com/article/ethanol-fails-lower-gas-prices-study-finds/ |archive-date=October 11, 2016 }}</ref> while a runup in the price of government mandated [[Renewable Identification Number]] credits has driven up the price of gasoline.<ref>{{cite news|url=https://www.bloomberg.com/news/2013-03-21/gasoline-price-inflated-by-ethanol-in-oil-boom-energy-markets.html|title=Gasoline Price Inflated by Ethanol in Oil Boom: Energy Markets
|newspaper=Bloomberg.com
|date=March 21, 2013 |access-date=May 15, 2014 |url-status=live |archive-url=https://web.archive.org/web/20141109044848/http://www.bloomberg.com/news/2013-03-21/gasoline-price-inflated-by-ethanol-in-oil-boom-energy-markets.html |archive-date=November 9, 2014 }}</ref> These are in contrast to a May 2012, Center for Agricultural and Rural Development study which showed a $0.29 to $1.09 reduction in per gallon gasoline price from ethanol use.<ref>{{cite web|url=http://www.ethanolrfa.org/exchange/entry/ethanol-keeps-gasoline-prices-1.09-cheaper/ |title=Ethanol Keeps Gasoline Prices $1.09 Cheaper |access-date=August 22, 2014 |url-status=live |archive-url=https://web.archive.org/web/20150501001524/http://www.ethanolrfa.org/exchange/entry/ethanol-keeps-gasoline-prices-1.09-cheaper/ |archive-date=May 1, 2015 |date=May 15, 2012 }}</ref>

The U.S. consumed {{convert|138.2|e9USgal|e6m3|abbr=on}} of gasoline in 2008, blended with about {{convert|9.6|e9USgal|e6m3|abbr=on}} of ethanol, representing a [[market share]] of almost 7% of supply by volume. Given its lower [[Energy content of biofuel|energy content]], ethanol fuel displaced about {{convert|6.4|e9USgal|e6m3|abbr=on}} of gasoline, representing 4.6 percent in [[Barrel of oil equivalent|equivalent energy units]].<ref name=EIA2008/>

The EPA announced in November 2013, a reduction in mandated U.S. 2014 ethanol production, due to "market conditions".<ref>http://www.chadbourne.com/EthanolLosesSteamButOnlyinPart_projectfinance/ {{dead link|date=December 2016 |bot=InternetArchiveBot |fix-attempted=yes }}</ref><ref>{{cite web|url=http://www.agweb.com/article/epa_succumbs_to_pressure_to_reduce_ethanol_mandate_NAA_Boyce_Thompson/ |title=EPA Succumbs to Pressure to Reduce Ethanol Mandate |access-date=August 22, 2014 |url-status=live |archive-url=https://web.archive.org/web/20160527023725/http://www.agweb.com/article/epa_succumbs_to_pressure_to_reduce_ethanol_mandate_naa_boyce_thompson/ |archive-date=May 27, 2016 }}</ref>

==Tariffs and tax credits==
Since the 1980s until 2011, domestic ethanol producers were protected by a 54-cent per gallon import [[tariff]], mainly intended to curb Brazilian [[sugarcane ethanol]] imports. Beginning in 2004 blenders of transportation fuel received a [[tax credit]] for each gallon of ethanol they mix with gasoline.<ref name=Economist062311>{{cite news|url=http://www.economist.com/node/18867278?story_id=18867278|title=Ethanol subsidies: Fiscal sobriety|newspaper=[[The Economist]]|date=June 23, 2011|access-date=June 25, 2011}} Print edition June 25 – July 1, pp. 38.</ref><ref name=NYT061711/> Historically, the tariff was intended to offset the federal tax credit that applied to ethanol regardless of country of origin.<ref name=NYT100406/><ref name=Tariff54c>{{cite web |url=http://www.ethanolproducer.com/article.jsp?article_id=4591 |title=Brazil launches campaign to remove ethanol tariff|work=Ethanol Producer Magazine|author=Anna Austin |date=September 2008 |access-date=June 24, 2009}}</ref> Several countries in the [[Caribbean Basin]] imported and reprocessed Brazilian ethanol, usually converting [[hydrous|hydrated]] ethanol into [[anhydrous]] ethanol, for re-export to the United States. They avoided the 2.5% duty and the tariff, thanks to the [[Caribbean Basin Initiative|Caribbean Basin Initiative (CBI)]] and [[free trade agreement]]s. This process was limited to 7% of U.S. ethanol consumption.<ref name="CBI">{{cite news|url=http://www.agra-net.com/portal2/home.jsp?template=pubarticle&artid=1326276553177&pubid=ag072|title=ITC Fixes 2012 CBI Fuel Ethanol Import Quota|work=agranet.com|date=January 13, 2012|access-date=November 23, 2013}}</ref>

As of 2011, blenders received a {{USD|0.45}} per gallon tax credit, regardless of feedstock; small producers received an additional {{USD|0.10}} on the first 15 million US gallons; and producers of cellulosic ethanol received credits up to {{USD|1.01}}. Tax credits to promote the production and consumption of [[biofuel]]s date to the 1970s. For 2011, credits were based on the [[Energy Policy Act of 2005]], the [[Food, Conservation, and Energy Act of 2008]], and the [[Energy Improvement and Extension Act of 2008]].<ref name=CBO2010/>

A 2010 study by the [[Congressional Budget Office]] (CBO) found that in fiscal year 2009, biofuel tax credits reduced federal revenues by around {{USD|6}} billion, of which corn and cellulosic ethanol accounted for {{USD|5.16}} billion and {{USD|50}} million, respectively.{{Citation needed|date=January 2021}}

In 2010, CBO estimated that taxpayer costs to reduce gasoline consumption by one gallon were $1.78 for corn ethanol and $3.00 for cellulosic ethanol. In a similar way, and without considering potential indirect land use effects, the costs to taxpayers of reducing greenhouse gas emissions through tax credits were about $750 per metric ton of [[CO2-equivalent|{{CO2}}-equivalent]] for ethanol and around $275 per metric ton for cellulosic ethanol.<ref name=CBO2010>{{cite web|url=http://www.cbo.gov/ftpdocs/114xx/doc11477/07-14-Biofuels.pdf|title=Using Biofuel Tax Credits to Achieve Energy and Environmental Policy Goals |publisher=[[Congressional Budget Office]]|date=July 2010|access-date=July 25, 2010}}</ref>

On June 16, 2011, the [[U.S. Congress]] approved an amendment to an economic development bill to repeal both the tax credit and the tariff, but this bill did not move forward.<ref name=Economist062311/><ref name=NYT061711>{{cite news|url=http://green.blogs.nytimes.com/2011/06/17/ethanol-industry-is-unruffled-by-senate-vote-against-tax-breaks/?scp=8&sq=ethanol%20fuel%20subsidies&st=cse|title=Ethanol Industry Is Unruffled by Senate Vote Against Tax Breaks|author=Clifford Krauss|work=The New York Times|date=June 17, 2011|access-date=June 25, 2011}}</ref> Nevertheless, the U.S. Congress did not extend the tariff and the tax credit, allowing both to end on December 31, 2011.<ref name=USTariff/><ref>{{cite news|url=https://www.nytimes.com/2012/01/02/business/energy-environment/after-three-decades-federal-tax-credit-for-ethanol-expires.html|title=After Three Decades, Tax Credit for Ethanol Expires|author=Robert Pear|work=The New York Times|date=January 1, 2012|access-date=January 4, 2012}}</ref> Since 1980 the ethanol industry was awarded an estimated {{USD|45}} billion in subsidies.<ref name=USTariff>{{cite news|url=http://www.detroitnews.com/article/20111224/AUTO01/112240320/1148/auto01/Congress-ends-corn-ethanol-subsidy |title=Congress ends corn ethanol subsidy |author=David Shepardson |work=[[The Detroit News]] |date=December 24, 2011 |access-date=December 29, 2011 |url-status=dead |archive-url=https://web.archive.org/web/20120106204543/http://www.detroitnews.com/article/20111224/AUTO01/112240320/1148/auto01/Congress-ends-corn-ethanol-subsidy |archive-date=January 6, 2012 }}</ref>

==Feedstocks==
===Corn===
{{Main article|Corn ethanol}}
Corn is the main feedstock used for producing ethanol fuel in the United States.<ref name=Ethanol/><ref name=RFA2010/> Most of the controversies surrounding U.S. ethanol fuel production and use is related to corn ethanol's [[Net energy gain|energy balance]] and its [[#Environmental and social impact|social and environmental impacts]].{{citation needed|date=November 2011}}<!--Given that corn is the main fuel source, this section needs more bulk.-->

===Cellulose===
{{Main article|Cellulosic ethanol}}
Cellulosic sources have the potential to produce a renewable, cleaner-burning, and [[carbon offset|carbon-neutral]] alternative to gasoline.{{citation needed|date=November 2011}} In his [[State of the Union Address]] on January 31, 2006, President [[George W. Bush]] stated, "We'll also fund additional research in cutting-edge methods of producing ethanol, not just from corn, but from wood chips and stalks or [[switchgrass]]. Our goal is to make this new kind of ethanol practical and competitive within six years."{{Citation needed|date=January 2021}}

On July 7, 2006, DOE announced a new research agenda for cellulosic ethanol. The 200-page [[Technology roadmap|scientific roadmap]] cited recent advances in [[biotechnology]] that could aid use of cellulosic sources. The report outlined a detailed research plan for additional technologies to improve production efficiency. The roadmap acknowledged the need for substantial [[subsidy|federal loan guarantees]] for [[Biorefinery|biorefineries]].{{Citation needed|date=January 2021}}

The [[United States federal budget, 2007|2007 federal budget]] earmarked $150 million for the research effort – more than doubling the 2006 budget. DOE invested in [[enzyme|enzymatic]], [[Thermal depolymerization|thermochemical]], [[Hydrolysis|acid hydrolysis]], hybrid hydrolysis/enzymatic, and other research approaches targeting more efficient and lower&ndash;cost conversion of cellulose to ethanol.{{Citation needed|date=January 2021}}

The first materials considered for cellulosic biofuel included plant matter from agricultural waste, yard waste, sawdust and paper. Professors R. Malcolm Brown Jr. and David Nobles, Jr. of the [[University of Texas at Austin]] developed [[cyanobacteria]] that had the potential to produce cellulose, [[glucose]] and [[sucrose]], the latter two easily converted into ethanol. This offers the potential to create ethanol without plant matter.{{citation needed|date=November 2011}}

===Sugar===
{| class="wikitable" style="float: right; margin-left: 10px"
! colspan="6" style="text-align:center; background:#cfc;"|{{U.S.}} fuel ethanol<br />imports by country (2002–2007)<ref name=RFA1E>{{cite web|url=http://www.ethanolrfa.org/industry/statistics/#D|title=Industry Statistics: U.S. Fuel Ethanol Demand|publisher=Renewable Fuels Association|author=RFA, International Trade Commission, and Jim Jordan & Associates|access-date=April 17, 2010 |archive-url = https://web.archive.org/web/20080408091334/http://www.ethanolrfa.org/industry/statistics/#D |archive-date = April 8, 2008}}</ref><br /><small>(Millions of U.S. liquid gallons)</small>
|-
!Country
!2007
!2006
!2005
!2004
!2003
|-
|{{BRA}} || 188.8|| 433.7|| 31.2 || 90.3|| 0
|-
|{{JAM}} || 75.2|| 66.8 || 36.3|| 36.6|| 39.3
|-
|{{ESA}} || 73.3|| 38.5 || 23.7|| 5.7|| 6.9
|-
|{{flag|Trinidad and Tobago}} || 42.7|| 24.8 || 10.0|| 0|| 0
|-
|{{CRI}} || 39.3|| 35.9|| 33.4|| 25.4|| 14.7
|}

Producing ethanol from [[sugar]] is simpler than converting corn into ethanol. Converting sugar requires only a [[yeast]] [[Ethanol fermentation|fermentation]] process. Converting corn requires additional cooking and the application of [[enzyme]]s. The energy requirement for sugar conversion is about half that for corn.{{citation needed|date=November 2011}} Sugarcane produces more than enough energy to do the conversion with energy left over. A 2006 [[U.S. Department of Agriculture]] report found that at market prices for ethanol, converting sugarcane, [[sugar beet]]s and [[molasses]] to ethanol would be profitable.<!-- without subsidies? --><ref>"The Economic Feasibility of Ethanol Production from Sugar in the United States" 2006 [[United States Department of Agriculture]] {{cite web|url=http://www.usda.gov/oce/EthanolSugarFeasibilityReport3.pdf |title=Archived copy |access-date=September 4, 2007 |url-status=dead |archive-url=https://web.archive.org/web/20070815063506/http://www.usda.gov/oce/EthanolSugarFeasibilityReport3.pdf |archive-date=August 15, 2007 }}.</ref> As of 2008 researchers were attempting to breed new varieties adapted to U.S. soil and weather conditions, as well as to take advantage of [[cellulosic ethanol]] technologies to also convert sugarcane [[bagasse]].<ref name="EthaPro09"/><ref name="ARS08">{{cite journal|url=http://www.ars.usda.gov/is/AR/archive/oct08/ethanol1008.htm?pf=1|journal=[[Agricultural Research Magazine]]|publisher=[[USDA]] [[Agricultural Research Service]]|author=Jan Suszkiw|title=Research Helps Set the Stage for Ethanol&nbsp;...<!-- ellipsis in the original --> Southern Style|date=October 2008|access-date=February 12, 2009}}</ref>

U.S. sugarcane production occurs in [[Florida]], [[Louisiana]], [[Hawaii]], and [[Texas]]. The first three plants to produce sugarcane-based ethanol went online in Louisiana in mid-2009. Sugar mills in [[Lacassine, Louisiana|Lacassine]], [[St. James Parish, Louisiana|St. James]] and [[Bunkie, Louisiana|Bunkie]] were converted to sugarcane ethanol production using [[Colombia]]n technology to enable profitable ethanol production. These three plants planned to produce {{convert|100|e6USgal|e3m3|abbr=on}} of ethanol per year within five years.<ref name="ARS08"/><ref>{{cite news|url=http://www.greencarcongress.com/2008/06/columbian-group.html|newspaper=Miami Herald|author=Gerardo Reyes|title=Colombians in U.S. sugar mills to produce ethanol|date=June 8, 2008|access-date=December 6, 2008}}</ref><ref>{{cite web|url=http://saldefrutas.com/louisiana/who.html|publisher=Louisiana Green Fuels|title=LGF web page|access-date=December 6, 2008|url-status=dead|archive-url=https://web.archive.org/web/20160115195026/http://saldefrutas.com/louisiana/who.html|archive-date=January 15, 2016}} This site presents the same information included in the ''Miami Herald'' article of June 8, 2008.</ref>

By 2009 two other sugarcane ethanol production projects were being developed in [[Kauai]], Hawaii and [[Imperial Valley]], California. The Hawaiian plant was projected to have a capacity of between {{convert|12|-|15|e6USgal|e3m3}} a year and to supply local markets only, as shipping costs made competing in the [[continental US]] impractical. This plant went online in 2010. The California plant was expected to produce {{convert|60|e6USgal|e3m3|abbr=on}} a year in 2011.<ref name="EthaPro09">{{cite journal|url=http://ethanolproducer.com/article.jsp?article_id=5345&q=&page=all|journal=Ethanol Producer Magazine|author=Erin Voegele|title=Sugarcane Economics|date=March 2009|access-date=February 12, 2009}}</ref>
[[File:Bushlulapetrobras09032007.jpg|right|thumb|200px|Presidents George W. Bush and [[Luiz Inácio Lula da Silva]] during Bush's visit to Brazil, March 2007.]]
In March 2007, "ethanol diplomacy" was the focus of President George W. Bush's Latin American tour, in which he and Brazil's president, [[Luiz Inacio Lula da Silva]], promoted the production and use of sugarcane ethanol throughout the [[Caribbean Basin]]. The two countries agreed to share technology and set international biofuel standards.<ref name="WasPos1">{{cite news |url=https://www.washingtonpost.com/wp-dyn/content/article/2007/02/22/AR2007022201361.html |title=Latin America – the 'Persian Gulf' of Biofuels? |newspaper=The Washington Post|author= Marcela Sanchez |date=February 23, 2007 |access-date=May 3, 2008}}</ref> Brazilian sugarcane technology transfer was intended to permit various [[Central American]], such as [[Honduras]], [[El Salvador]], [[Nicaragua]], [[Costa Rica]] and [[Panama]], several [[Caribbean]] countries, and various [[Andean Community of Nations|Andean Countries]] tariff-free trade with the U.S., thanks to existing trade agreements. The expectation was that such countries would export to the United States in the short-term using Brazilian technology.<ref>{{cite news |url=https://www.nytimes.com/2007/03/03/business/worldbusiness/03ethanol.html?scp=1&sq=Bush+Brazil+ethanol&st=nyt |title=U.S. and Brazil Seek to Promote Ethanol in West |newspaper=The New York Times |author1=Edmund L. Andrews |author2=Larry Rother |date=March 3, 2007 |access-date=April 28, 2008}}</ref>

In 2007, combined exports from [[Jamaica]], El Salvador, [[Trinidad and Tobago]] and Costa Rica to the U.S. reached a total of {{convert|230.5|e6USgal|e3m3|abbr=on}} of sugarcane ethanol, representing 54.1% of imports. [[Brazil]] began exporting ethanol to the U.S. in 2004 and exported {{convert|188.8|e6USgal|e3m3|abbr=on}} representing 44.3% of U.S. ethanol imports in 2007. The remaining imports that year came from [[Canada]] and [[China]].<ref name="RFA1E"/>

===Other feedstocks===
Cheese [[whey]], [[barley]], [[potato]] waste, beverage waste, and [[brewery]] and [[beer]] waste have been used as feedstocks for ethanol fuel, but at a far smaller scale than corn and sugarcane ethanol, as plants using these feedstocks have the capacity to produce only {{convert|3|to|5|e6USgal|e3m3}} per year.<ref name=RFA2010/>

==Comparison with Brazilian ethanol==
Sugarcane ethanol has an energy balance seven times greater than corn ethanol.<ref name="Wilson">{{cite web|url=http://www.wilsoncenter.org/topics/pubs/Brazil_SR_e3.pdf |title=Brazil Institute Special Report: The Global Dynamics of Biofuels |editor=Daniel Budny and Paulo Sotero|publisher=Brazil Institute of the Woodrow Wilson Center |date=April 2007 |access-date=May 3, 2008 |url-status=dead |archive-url=https://web.archive.org/web/20080528051442/http://www.wilsoncenter.org/topics/pubs/Brazil_SR_e3.pdf |archive-date=May 28, 2008 }}</ref> As of 2007, Brazilian distiller production costs were 22 cents per liter, compared with 30 cents per liter for corn-based ethanol.<ref>{{cite news
|newspaper=The Economist
|date=March 3–9, 2007 |title=Fuel for Friendship |pages=44}}</ref> Corn-derived ethanol costs 30% more because the corn starch must first be converted to sugar before distillation into [[ethanol|alcohol]].<ref name=NYT100406>{{cite news|url=https://www.nytimes.com/2006/04/10/world/americas/10brazil.html?pagewanted=1&sq=Bush%20Brazil%20ethanol&st=nyt&scp=5 |title=With Big Boost From Sugar Cane, Brazil Is Satisfying Its Fuel Needs |author=Larry Rother|newspaper=The New York Times|date=April 10, 2006|access-date=April 28, 2008}}</ref> However, corn-derived ethanol offers the ability to return 1/3 of the feedstock to the market as a replacement for the corn used in the form of [[Distillers grains|Distillers Dried Grain]].<ref name="Ethanol"/> Sugarcane ethanol production is seasonal: unlike corn, sugarcane must be processed into ethanol almost immediately after harvest.<ref>{{cite web|title=Short-Term Energy Outlook|url=http://www.eia.gov/forecasts/steo/archives/aug12.pdf|publisher=US Energy Information Administration|access-date=August 9, 2012|date=August 2012}}</ref>

{| class="wikitable" style="margin: 1em auto 1em auto"
! colspan="4" style="text-align:center; background:#abcdef;"|Comparison of key characteristics between<br />the ethanol industries in the United States and Brazil
|- align=center
| style="background:#abcdef;"| Characteristic|| style="background:#abcdef;"| {{BRA}} || style="background:#abcdef;"|{{flag|U.S.}} || style="background:#abcdef;"| Units/comments
|-
|Main feedstock ||align=center| Sugar cane ||align=center|Corn || <small>Main [[cash crop]] for ethanol production, the US has less than 2% from other crops.</small>
|-
|Total ethanol fuel production (2011)<ref name=RFAOutlook2012/>||{{center|5,573}}||{{center|13,900}}|| <small>Million U.S. liquid gallons </small>
|-
|Total arable land<ref name="Veja_30_04">{{cite web|url=http://veja.abril.com.br/300408/p_058.shtml |title=Ele é o falso vilão |author=Julia Duailibi |work=[[Veja (magazine)|Veja]]|language=pt |date=April 27, 2008 |access-date=May 3, 2008 |url-status=dead |archive-url=https://web.archive.org/web/20080506103110/http://veja.abril.com.br/300408/p_058.shtml |archive-date=May 6, 2008 }}</ref>||align=center| 355 ||align=center| 270 || <small>Million hectares. Only contiguous U.S., excludes Alaska.</small>
|-
|Total area used for ethanol crop (2006)<ref name="Ethanol"/><ref name="Veja_30_04"/> ||align=center| 3.6<br /><small>(1%)</small>||align=center| 10<br /><small>(3.7%)</small>|| <small>Million hectares (% total arable)</small>
|-
|Productivity<ref name="Ethanol"/><ref name="Wilson"/><ref name="Veja_30_04"/><ref name="Epoca_16_06">{{cite web|url=http://revistaepoca.globo.com/Revista/Epoca/0,,EMI5865-15273.html |title=Por que a cana é melhor que o milho |work=[[Época (Brazilian magazine)|Época]] |author=Maria Helena Tachinardi |date=June 13, 2008 |language=pt |access-date=August 6, 2008 |url-status=dead |archive-url=https://web.archive.org/web/20080707090818/http://revistaepoca.globo.com/Revista/Epoca/0%2C%2CEMI5865-15273.html |archive-date=July 7, 2008 }} Print edition pp. 73</ref>||align=center| 6,800–8,000 ||align=center| 3,800–4,000 || <small>Ethanol yield (liter/hectare). Brazil is 727 to 870 gal/acre (2006), US is 321 to 424 gal/acre (2003–05)</small>
|-
|Energy balance (input energy productivity)<ref name="Ethanol"/><ref name=NYT100406/><ref name="MLA_2004">{{cite web|url=http://www.eners.ch/plateforme/medias/macedo_2004.pdf |author= Macedo Isaias, M. Lima Verde Leal and J. Azevedo Ramos da Silva|title= Assessment of greenhouse gas emissions in the production and use of fuel ethanol in Brazil|publisher=Secretariat of the Environment, Government of the State of São Paulo|year=2004|access-date=May 9, 2008|archive-url = https://web.archive.org/web/20080528051443/http://www.eners.ch/plateforme/medias/macedo_2004.pdf |archive-date = May 28, 2008}}</ref>||align=center| 8.3 to 10.2 ||align=center| 1.3 to 1.6||<small>Ratio of the energy obtained from ethanol/energy expended in its production</small>
|-
|Estimated greenhouse gas emission reduction<ref name="WorldBank" /><ref name="Science08">{{cite journal|title=Use of U.S. Croplands for Biofuels Increases Greenhouse Gases Through Emissions from Land-Use Change|author=Timothy Searchinger|journal=[[Science (journal)|Science]]|volume=319 |issue=5867 |pages=1238–1240|doi=10.1126/science.1151861|date=February 29, 2008|pmid=18258860|bibcode=2008Sci...319.1238S|s2cid=52810681|display-authors=etal|doi-access=free}} Originally published online in Science Express on February 7, 2008. See Letters to ''Science'' by Wang and Haq. There are critics to these findings for assuming a worst-case scenario.</ref><ref name="Ethanol"/> ||align=center| 86–90%<sup>(1)</sup>||align=center| 10–30%<sup>(1)</sup> ||<small> % GHGs avoided by using ethanol instead of gasoline, using existing crop land, without [[ILUC]] effects.</small>
|-
|[[United States Environmental Protection Agency|EPA]]'s estimated 2022 GHG reduction for [[Renewable Fuel Standard|RFS2]].<ref name=EPAfinal2010>{{cite web|url=http://www.epa.gov/otaq/renewablefuels/420r10006.pdf |title=Renewable Fuel Standard Program (RFS2) Regulatory Impact Analysis |publisher=EPA |date=February 2010 |access-date=February 12, 2010 |url-status=dead |archive-url=https://web.archive.org/web/20110202202402/http://www.epa.gov/otaq/renewablefuels/420r10006.pdf |archive-date=February 2, 2011 }} ''See pp. 480 and 489, Figures 2.6-1 and 2.6–9''.</ref> ||align=center| 61%<sup>(2)</sup>||align=center| 21% ||<small>Average % GHGs change as compared to gasoline and considering direct and indirect land use change effects.</small>
|-
|[[California Air Resources Board|CARB]]'s [[Life-cycle analysis|full life-cycle]] carbon intensity<ref name="ARBproposal">{{cite web |url= http://www.arb.ca.gov/regact/2009/lcfs09/lcfsisor1.pdf |title=Proposed Regulation to Implement the Low Carbon Fuel Standard. Volume I: Staff Report: Initial Statement of Reasons|publisher=[[California Air Resources Board]]|date=March 5, 2009|access-date=April 26, 2009}}</ref><ref name="CARBruleB">{{cite web|url=http://www.arb.ca.gov/fuels/lcfs/lcfs_att_b_mod.pdf|title=Draft Attachment B: Public Hearing to Consider Adoption of a Proposed Regulation to Implement the Low Carbon Fuel Standard – Staff's Suggested Modifications to the Original Proposal|date=April 23, 2003|publisher=CARB|access-date=April 30, 2009|archive-date=June 13, 2009|archive-url=https://web.archive.org/web/20090613042326/http://www.arb.ca.gov/fuels/lcfs/lcfs_att_b_mod.pdf|url-status=dead}}</ref>||align=center|73.40||align=center|105.10<sup>(3)</sup>||<small>Grams of [[carbon dioxide equivalent|CO<sub>2</sub> equivalent]] released per [[megajoule|MJ]] of energy produced, includes [[Indirect land use change impacts of biofuels|indirect land use changes]].<ref name="Science08"/></small>
|-
|Estimated payback time for [[greenhouse gas emission]]<ref name="Oxfam">{{cite web|url=http://www.oxfam.org/files/bp114-inconvenient-truth-biofuels-0806.pdf |title=Another Inconvenient Truth |publisher=[[Oxfam]] |date=June 28, 2008 |access-date=August 6, 2008 |url-status=dead |archive-url=https://web.archive.org/web/20080819214631/http://www.oxfam.org/files/bp114-inconvenient-truth-biofuels-0806.pdf |archive-date=August 19, 2008 }}Oxfam Briefing Paper 114, figure 2 pp.8</ref> ||align=center| 17 years<sup>(4)</sup>||align=center| 93 years<sup>(4)</sup>||<small>Brazilian [[cerrado]] for sugar cane and US [[grassland]] for corn. Land use change scenarios by Fargione et al.<ref name="Fargione08">{{cite journal|title=Land Clearing and the Biofuel Carbon Debt |author=Fargione |journal=Science|volume=319 |issue=5867 |pages=1235–1238 |date=February 29, 2008 |pmid= 18258862|doi= 10.1126/science.1152747|last2= Hill|first2= J.|last3= Tilman|first3= D.|last4= Polasky|first4= S.|last5= Hawthorne|first5= P.|bibcode=2008Sci...319.1235F |s2cid=206510225 |display-authors=etal}} Originally published online in Science Express on February 7, 2008. There are rebuttals to these findings for assuming a worst-case scenario</ref></small>
|-
|Flexible-fuel vehicles produced/sold<br />(includes autos, light trucks and motorcycles)<ref name=FFV10mi>{{cite news|url=http://wheels.blogs.nytimes.com/2012/03/01/flex-fuel-amendment-makes-for-strange-bedfellows/?ref=automobiles|title=Flex-Fuel Amendment Makes for Strange Bedfellows|author=Jim Motavalli|work=The New York Times|date=March 1, 2012|access-date=March 18, 2012}}</ref><ref name=ANFAVEA2010>{{cite web|url=http://www.virapagina.com.br/anfavea2011/|title=Anúario da Industria Automobilistica Brasileira 2011: Tabela 2.3 Produção por combustível - 1957/2010|publisher=ANFAVEA - Associação Nacional dos Fabricantes de Veículos Automotores (Brasil)|access-date=January 22, 2012|language=pt|archive-date=May 31, 2013|archive-url=https://web.archive.org/web/20130531070340/http://www.virapagina.com.br/anfavea2011/|url-status=dead}} pp. 62-63.</ref><ref name=ANFAVEA2011>{{cite web|url=http://www.anfavea.com.br/cartas/Carta308.pdf |title=Licenciamento total de automóveis e comerciais leves por combustível |trans-title=Total automobiles and light-trucks registered by fuel |language=pt |author=Renavam/Denatran |publisher=ANFAVEA |date=January 2012 |access-date=January 21, 2012 |url-status=dead |archive-url=https://web.archive.org/web/20120131115223/http://www.anfavea.com.br/cartas/Carta308.pdf |archive-date=January 31, 2012 }} ''Carta de ANFAVEA 308'' pp. 4.</ref> ||align=center| 16.3 million||align=center| 10 million|| <small> All fleets as of December 2011. The Brazilian fleet includes 1.5 million flex fuel motorcycles.<ref name=MotoFlex09>{{cite web|url=http://unica.com.br/noticias/show.asp?nwsCode=4771CECF-FDB8-43B5-9CF9-E342B99F5C23 |title=Motos flex foram as mais vendidas em 2009 na categoria 150cc |author=Abraciclo |publisher=[[UNICA, Brazil|UNICA]] |date=January 27, 2010 |access-date=February 10, 2010 |language=pt |url-status=dead |archive-url=https://archive.today/20121205031059/http://unica.com.br/noticias/show.asp?nwsCode=4771CECF-FDB8-43B5-9CF9-E342B99F5C23 |archive-date=December 5, 2012 }}</ref><ref name=MotoFlex10>{{cite web|url=http://www.abraciclo.com.br/images/stories/dados_setor/motocicletas/producao/2010%20produo-dezcorreto.pdf|title=Produção Motocicletas 2010|publisher=ABRACICLO|access-date=February 5, 2011|language=pt}}</ref><ref name=MotoFlex11>{{cite web|url=http://www.abraciclo.com.br/images/stories/dados_setor/motocicletas/producao/2011%20produo-dezembro.pdf|title=Produção Motocicletas 2011|trans-title=2011 Motorcycle Production|publisher=ABRACICLO|access-date=January 21, 2012|language=pt}}</ref><br />[[USDOE]] estimates that in 2009 only 504,297 flex-fuel vehicles were regularly fueled with E85 in the US.<ref name=USeDataBook/></small>
|-
|Ethanol fueling stations in the country||align=center| 35,017<br /><small>(100%)</small>||align=center| 2,749<br /><small>(1.6%)</small>||<small>As % of total gas stations in the country. Brazil by December 2007,<ref name=ANP08stats>{{cite web|url=http://www.anp.gov.br/doc/conheca/anuario_anp_2008.pdf |title=Anuário Estatístico Brasileiro do Petróleo, Gás Natural e Biocombustíveis 2008 |publisher=Agência Nacional do Petróleo, Gás Natural e Biocombustíveis |year=2008 |access-date=July 10, 2009 |language=pt |url-status=dead |archive-url=https://web.archive.org/web/20091003154045/http://www.anp.gov.br/doc/conheca/anuario_anp_2008.pdf |archive-date=October 3, 2009 }} ''See Table 3.17, pp. 138''.</ref> U.S. by May 2011.<ref name=E85prices/> (170,000 total.<ref name="Apollo"/>)</small>
|-
|Ethanol's share within the gasoline market<ref name=USDA0410/><ref name="ANP07_2008">{{cite web|url=http://br.invertia.com/noticias/noticia.aspx?idNoticia=200807152306_ABR_77211977 |title=ANP: consumo de álcool combustível é 50% maior em 2007 |author=Agência Brasil |date=July 15, 2008 |publisher=Invertia |access-date=August 9, 2008 |language=pt |url-status=dead |archive-url=https://web.archive.org/web/20081226014527/http://br.invertia.com/noticias/noticia.aspx?idNoticia=200807152306_ABR_77211977 |archive-date=December 26, 2008 }}</ref><ref name="ANP02_2008">{{cite web|url=http://www.agropecuariabrasil.com.br/anp-estima-que-consumo-de-alcool-supere-gasolina/ |title=ANP estima que consumo de álcool supere gasolina |author=Gazeta Mercantil |year=2008 |publisher=Agropecuária Brasil |access-date=August 9, 2008 |language=pt |url-status=dead |archive-url=https://web.archive.org/web/20080601174307/http://www.agropecuariabrasil.com.br/anp-estima-que-consumo-de-alcool-supere-gasolina/ |archive-date=June 1, 2008 }}</ref><ref name="Brazil48_20">{{cite news|url=http://www.washingtontimes.com/article/20080507/COMMENTARY/381443705/1012/commentary |title=Brazil's energy plan examined |author=D. Sean Shurtleff |date=May 7, 2008 |newspaper=The Washington Times |access-date=May 10, 2008 |url-status=dead |archive-url=https://web.archive.org/web/20080510071440/http://www.washingtontimes.com/article/20080507/COMMENTARY/381443705/1012/commentary |archive-date=May 10, 2008 }}</ref> ||align=center| 50%<sup>(5)</sup>||align=center| 10% ||<small>As % of total consumption on a volumetric basis. Brazil as of April 2008. U.S. as of December 2010.</small>
|-
|Cost of production (USD/US gallon)<ref name="Wilson"/> ||align=center| 0.83||align=center| 1.14|| <small>2006/2007 for Brazil (22¢/liter), 2004 for U.S. (35¢/liter) </small>
|-
| colspan="4" style="text-align:left;"| <small>'''Notes:''' (1) Assuming no land use change.<ref name="Science08"/> (2) Estimate is for U.S. consumption and sugarcane ethanol is imported from Brazil. Emissions from sea transport are included. Both estimates include land transport within the U.S.<ref name=EPAfinal2010/> (3) [[Low-carbon fuel standard#California Low-Carbon Fuel Standard|CARB]] estimate for Midwest corn ethanol. [[California]]'s gasoline carbon intensity is 95.86 blended with 10% ethanol.<ref name="ARBproposal"/><ref name="CARBruleB"/> (4) Assuming direct land use change.<ref name="Fargione08"/> (5) If diesel-powered vehicles are included and due to ethanol's lower energy content by volume, bioethanol represented 16.9% of the road sector energy consumption in 2007.<ref name=BEN2008>{{cite web|url=http://www.mme.gov.br/site/menu/select_main_menu_item.do?channelId=1432&pageId=17726 |title=Balanço Energético Nacional 2008: Ano base 2007 |author=Empresa de Pesquisa Energética |format=PDF (link to download) |date=November 2008 |publisher=Ministério de Minas e Energia do Brasil |access-date=February 22, 2009 |language=pt |url-status=dead |archive-url=https://web.archive.org/web/20090319212002/https://www.mme.gov.br/site/menu/select_main_menu_item.do?channelId=1432 |archive-date=March 19, 2009 }} ''Tables 3.6a and 3.6b. Data expressed in energy equivalent ([[Tonne of oil equivalent|toe]]). Report is based in 2007 data.''</ref></small> 
|}

== Environmental and social impact ==

=== Environmental effects ===
{{See also|Issues relating to biofuels}}

====Energy balance and carbon intensity====
Until 2008, several full life cycle ("Well to Wheels") studies had found that corn ethanol reduces greenhouse gas emissions as compared to gasoline. In 2007 a team led by Farrel from the [[University of California, Berkeley]] evaluated six previous studies and concluded corn ethanol reduces [[greenhouse gas emissions]] by only 13 percent.<ref name=Farrel2006>{{cite journal|title=Ethanol Can Contribute to Energy and Environmental Goals|author=Farrel |journal=Science | volume=311 |issue=5760|pages=506–508 |date=January 27, 2006 |doi= 10.1126/science.1121416|pmid= 16439656|last2= Plevin|first2= RJ|last3= Turner|first3= BT|last4= Jones|first4= AD|last5= O'Hare|first5= M|last6= Kammen|first6= DM|bibcode=2006Sci...311..506F |s2cid=16061891 |display-authors=etal}}</ref><ref name=TwoBillion/><ref name=Wang205ppt/> Another figure is 20 to 30 percent, and an 85 to 85 percent reduction for cellulosic ethanol.<ref name=TwoBillion/><ref name=USEthanol>{{Cite book |author1=Goettemoeller, Jeffrey |author2=Adrian Goettemoeller | title = Sustainable Ethanol: Biofuels, Biorefineries, Cellulosic Biomass, Flex-Fuel Vehicles, and Sustainable Farming for Energy Independence | year = 2007| publisher = Prairie Oak Publishing, Maryville, Missouri |pages=40–41 | isbn = 978-0-9786293-0-4 }}</ref> Both figures were estimated by Wang from [[Argonne National Laboratory]], based on a comprehensive review of 22 studies conducted between 1979 and 2005, and simulations with Argonne's [[GREET Model|GREET model]]. All of these studies included direct [[land use change]]s.<ref name=Wang205ppt>{{cite web|url=http://www.transportation.anl.gov/pdfs/TA/354.pdf|title=Updated Energy and Greenhouse Gas Emission Results of Fuel Ethanol|author=Michael Wang|publisher=Center for Transportation Research, Argonne National Laboratory|access-date=June 7, 2009|archive-date=February 16, 2013|archive-url=https://web.archive.org/web/20130216035905/http://www.transportation.anl.gov/pdfs/TA/354.pdf|url-status=dead}} This is a public presentation of Michael Wang 2005 paper summarizing the results of the ANL study.</ref><ref name=Wang2005>{{cite web|url=http://www.transportation.anl.gov/pdfs/TA/375.pdf|title=Updated Energy and Greenhouse Gas Emission Results of Fuel Ethanol|author=Michael Wang|publisher=Center for Transportation Research, Argonne National Laboratory|access-date=June 7, 2009|archive-date=February 15, 2013|archive-url=https://web.archive.org/web/20130215202548/http://www.transportation.anl.gov/pdfs/TA/375.pdf|url-status=dead}} Presented at the 15th [[International Symposium on Alcohol Fuels]], San Diego, California.</ref> However, further research examining the actual effects of the [[Renewable Fuel Standard (United States)|Renewable Fuel Standard]] from 2008 to 2016 has concluded that corn ethanol produces more carbon emissions per unit of energy – likely more than 24% more – than gasoline, when factoring in fertilizer use and land use change.<ref name=":0">{{cite journal|last1=Lark|first1=Nathan|last2=Hendricks|date=2022|title=Environmental outcomes of the US Renewable Fuel Standard|journal=Proceedings of the National Academy of Sciences|volume=119|issue=9|pages=|doi=10.1073/pnas.2101084119|pmid=35165202|pmc=8892349 |bibcode=2022PNAS..11901084L }}</ref>

The reduction estimates on carbon intensity for a given biofuel depend on the assumptions regarding several variables, including crop productivity, agricultural practices, and distillery power source and energy efficiency. None of these earlier studies considered the effects of indirect [[land-use change]]s, and though their impact was recognized, its estimation was considered too complex and more difficult to model than direct land use changes.<ref name=TwoBillion>{{Cite book |author1=Sperling, Daniel |author2=Deborah Gordon | title = Two billion cars: driving toward sustainability | year = 2009 | pages = [https://archive.org/details/twobillioncarsdr00sper_0/page/98 98–99] | publisher = [[Oxford University Press]], New York | isbn = 978-0-19-537664-7 | url = https://archive.org/details/twobillioncarsdr00sper_0/page/98 }} ''For more detail see also the Notes 27 and 28 for Chapter 4, pp. 272''.</ref><ref name=WangLetScie>{{cite web |url=http://www.transportation.anl.gov/pdfs/letter_to_science_anldoe_03_14_08.pdf |title=Letter to Science about Searchinger et al. article |publisher=Argonne National Laboratory |author1=Michael Wang |author2=Zia Haq |date=March 14, 2008 |access-date=June 7, 2009 |archive-date=February 15, 2013 |archive-url=https://web.archive.org/web/20130215164552/http://www.transportation.anl.gov/pdfs/letter_to_science_anldoe_03_14_08.pdf |url-status=dead }} The published version on Science Letters is included in Searchinger E-Letter responses August 12, 2008.</ref> 

====Effects of land use change====
{{See also|Indirect land use change impacts of biofuels}} 
{| class="wikitable" style="float: right; margin-left: 10px"
! colspan="5" style="text-align:center; background:#cfc;"| Summary of Searchinger et al. (2008)<br />comparison of corn ethanol and gasoline [[Greenhouse gas|GHG]] emissions<br />with and without land use change<br />(CO<sub>2</sub> release rate (g/MJ))<ref name=Science08/><ref name=SearchingerSM/>
|- style="background:#cfc;" 
|| {{center|'''Fuel type<br />(U.S.)'''}} || style="background:#cfc;"| {{center|'''Carbon<br />intensity'''}} || style="background:#cfc;"| {{center|'''Reduction<br />GHG'''}} || style="background:#cfc;"|{{center|'''Carbon<br />intensity<br />+ [[ILUC]]'''}} || style="background:#cfc;"| {{center|'''Reduction<br />GHG'''}}
|-
| '''Gasoline''' || style="background:#ffc;"|{{center|'''92'''}} || {{center|-}} || style="background:#ffc;"|{{center|'''92'''}} ||{{center|-}}
|-
| Corn ethanol || {{center|74}} || {{center|-20%}} ||{{center|177}} ||{{center|+93%}}
|-
| Cellulosic ethanol || {{center|28}} || {{center|-70%}} ||{{center|138}} ||{{center|+50%}}
|-
| colspan="5" style="text-align:left;"|<small>Notes: Calculated using default assumptions for 2015 scenario for ethanol in [[Common ethanol fuel mixtures#E85|E85]].<br />Gasoline is a combination of conventional and [[reformulated gasoline]].<ref name=SearchingerSM>{{cite web|url=http://www.princeton.edu/~tsearchi/writings/SupportingMaterials.pdf |title=Supporting Materials for Use of U.S. Croplands for Biofuels Increases Greenhouse Gases Through Emissions from Land Use Change |author=Searchinger |publisher=Princeton University |access-date=June 11, 2009 |year=2008 |display-authors=etal |url-status=dead |archive-url=https://web.archive.org/web/20111010140245/http://www.princeton.edu/~tsearchi/writings/SupportingMaterials.pdf |archive-date=October 10, 2011 }} ''Data taken from Table 1B, pp. 21''.</ref></small>
|}
Two 2008 studies, both published in the same issue of [[Science (journal)|Scienceexpress]], questioned the previous assessments.<ref name=Fargione08/><ref name=Science08/><ref name=Times08>{{cite magazine|url=http://www.time.com/time/magazine/article/0,9171,1725975,00.html|archive-url=https://web.archive.org/web/20080330141602/http://www.time.com/time/magazine/article/0,9171,1725975,00.html|url-status=dead|archive-date=March 30, 2008|title=The Clean Energy Scam|date=March 27, 2008|magazine=[[Time (magazine)|Time]]|author=Michael Grunwald|access-date=December 4, 2008}}</ref> A team led by Searchinger from [[Princeton University]] concluded that once [[ILUC#Studies and controversy|direct and indirect effect of land use changes]] (ILUC) are considered, both corn and cellulosic ethanol increased carbon emissions as compared to gasoline by 93 and 50 percent respectively.<ref name="Science08"/> The study limited the analysis to a 30-year time horizon, assuming that land conversion emitted 25 percent of the carbon stored in soils and all carbon in plants cleared for cultivation. Brazil, China and [[India]] were considered among the overseas locations where land use change would occur as a result of diverting U.S. corn cropland, and it was assumed that new cropland in each of these regions correspond to different types of [[forest]], [[savanna]] or [[grassland]] based on the historical proportion of each natural land converted to cultivation in these countries during the 1990s.<ref name="Science08"/>

A team led by Fargione from [[The Nature Conservancy]] found that clearing natural lands for use as agricultural land to produce biofuel feedstock creates a carbon debt. Therefore, this carbon debt applies to both direct and indirect land use changes. The study examined six scenarios of wilderness conversion, Brazilian [[Amazon rainforest|Amazon]] to [[soybean]] biodiesel, Brazilian [[Cerrado]] to soybean biodiesel, Brazilian Cerrado to sugarcane ethanol, [[Indonesia]]n or [[Malaysia]]n lowland [[tropical rainforest]] to [[oil palm|palm]] biodiesel, Indonesian or Malaysian [[peatland]] tropical rainforest to [[oil palm]] forest, and U.S. Central grassland to corn ethanol.<ref name=Fargione08/>

====Low-carbon fuel standards====
{{Main article|Low-carbon fuel standard}}
On April 23, 2009, the [[California Air Resources Board]] approved specific rules and [[carbon intensity]] [[reference value]]s for the [[Low-carbon fuel standard#California Low-Carbon Fuel Standard|California Low-Carbon Fuel Standard]] (LCFS) that was to go into effect on January 1, 2011.<ref name="SFG042409">{{cite news |url=http://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2009/04/23/BABA1782HB.DTL&type=green&tsp=1 |title=Air Resources Board moves to cut carbon use |newspaper=San Francisco Chronicle |author=Wyatt Buchanan |date=April 24, 2009 |access-date=April 25, 2009}}</ref><ref name="NYT042409">{{cite news |url=https://nytimes.com/aponline/2009/04/24/us/AP-US-Low-Carbon-Fuel.html |title=Calif. Approves Nation's 1st Low-Carbon Fuel Rule|newspaper=The New York Times |agency=Associated Press|date=April 24, 2009 |access-date=April 25, 2009}} {{Dead link|date=August 2010|bot=RjwilmsiBot}}</ref><ref name="UNICA01">{{cite news|url=http://world-wire.com/news/0904230003.html |archive-url=https://web.archive.org/web/20090426072816/http://world-wire.com/news/0904230003.html |url-status=dead |archive-date=April 26, 2009 |title=Sugarcane Ethanol Passes Critical Test in California |publisher=World-Wire |author=UNICA Press release |date=April 24, 2009 |access-date=April 25, 2009 }}</ref> The consultation process produced controversy regarding the inclusion and modeling of indirect land use change effects.<ref>{{cite web |url=http://www.bioenergywiki.net/images/7/7b/DOE_letter.pdf |title=Public letter to Mary D. Nichols, Chairman California Air Resources Board |publisher=BioenergyWiki |date=June 24, 2008 |access-date=April 28, 2009 |archive-url=https://web.archive.org/web/20110723025639/http://www.bioenergywiki.net/images/7/7b/DOE_letter.pdf |archive-date=July 23, 2011 |url-status=dead }}</ref><ref>{{cite web |url=http://www.newfuelsalliance.org/NFA%20ARB%20ILUC%20Press%20Release%20Final.pdf |title=Leading Advanced Biofuel Companies, Researchers, Investors Call on Air Resources Board to Reconsider Draft Low Carbon Fuel Regulations |publisher=New Fuels Alliance |date=October 23, 2008 |access-date=April 26, 2009 |archive-date=May 9, 2009 |archive-url=https://web.archive.org/web/20090509051900/http://www.newfuelsalliance.org/NFA%20ARB%20ILUC%20Press%20Release%20Final.pdf |url-status=dead }}</ref><ref name="GCC08">{{cite web |url=http://www.greencarcongress.com/2008/10/biofuel-compani.html |title=Biofuel Companies Question ARB's Inclusion of Indirect Effects in Low Carbon Fuel Standard |publisher=Green Car Congress |date=October 24, 2008 |access-date=April 28, 2009}}</ref><ref>{{cite web|url=http://www.ucsusa.org/assets/documents/clean_vehicles/call_to_action_biofuels_and_land_use_change.pdf|title=Public letter to Mary D. Nichols, Chairman California Air Resources Board |publisher=[[Union of Concerned Scientists]] |date=April 21, 2009 |access-date=April 26, 2009}}</ref><ref>{{cite web |url=http://www.greencarcongress.com/2009/04/usc-lcfs-20090421.html|title=Group of Scientists and Economists Urge Inclusion of Indirect Land Use Change Effects for Biofuels and All Transportation Fuels in California LCFS |publisher=Green Car Congress |date=April 21, 2009 |access-date=April 28, 2009}}</ref> After the CARB's ruling, among other criticisms, representatives of the ethanol industry complained that the standard overstated the negative environmental effects of corn ethanol, and also criticized the inclusion of indirect effects of land-use changes as an unfair penalty to home-made corn ethanol because [[deforestation]] in the developing world had been tied to US ethanol production.<ref name="NYT042409"/><ref name="SciAm">{{cite magazine| url=http://www.scientificamerican.com/article.cfm?id=california-adopts-low-carF|title= California Adopts Low-Carbon Fuel Standard|author=Debra Kahn |magazine=[[Scientific American]] |date=April 24, 2009|access-date=May 4, 2009}} {{Dead link|date=September 2010|bot=H3llBot}}</ref><ref name="SFC042209">{{cite news |url=http://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2009/04/21/MN81175SHB.DTL |title=State readies stringent fuel standards |newspaper=San Francisco Chronicle |author=David R. Baker |date=April 22, 2009 |access-date=April 25, 2009}}</ref><ref name="NYT042409_2">{{cite news |url=http://greeninc.blogs.nytimes.com/tag/low-carbon-fuel-standard/?scp=1-b&sq=Calif.+approves+nation%27s+1st+low+carbon+fuel+standard&st=nyt |title=California Fuel Move Angers Ethanol Makers |newspaper=The New York Times |author= Kate Galbraith|date=April 24, 2009 |access-date=April 29, 2009}}</ref><ref name="BDigest">{{cite web|title=CARB votes 9–1 for California Low Carbon Fuel Standard; moves up indirect land use review to Jan 2011 in response to outcry on ILUC |url=http://www.biofuelsdigest.com/blog2/2009/04/24/carb-votes-9-1-for-california-low-carbon-fuel-standard-moves-up-indirect-land-use-review-to-jan-2011-in-response-to-outcry-on-iluc/ |publisher=BiofuelsDigest |author=Jim Lane |date=February 24, 2009 |access-date=April 29, 2009 |url-status=dead |archive-url=https://web.archive.org/web/20090911202522/http://www.biofuelsdigest.com/blog2/2009/04/24/carb-votes-9-1-for-california-low-carbon-fuel-standard-moves-up-indirect-land-use-review-to-jan-2011-in-response-to-outcry-on-iluc |archive-date=September 11, 2009 }}</ref><ref name="GreenM">{{cite web|url=http://www.greentechmedia.com/articles/california-adopts-low-carbon-fuel-standard-6083.html|title=California Adopts Low Carbon Fuel Standard|publisher=GreenMedia|author=Jeff St. John |date=April 23, 2009|access-date=May 4, 2009}}</ref><ref name="SACBee">{{cite news|url=http://www.sacbee.com/capitolandcalifornia/story/1808713.html |title=California's low-carbon fuel standard has oil companies anxious |newspaper=[[The Sacramento Bee]] |author=Dale Kasler |date=April 25, 2009 |access-date=May 4, 2009 |url-status=dead |archive-url=https://web.archive.org/web/20090430120657/http://www.sacbee.com/capitolandcalifornia/story/1808713.html |archive-date=April 30, 2009 }}</ref> The emissions standard for 2011 for LCFS meant that Midwest corn ethanol would not meet the California standard unless current carbon intensity is reduced.<ref name="SFG042409"/><ref name="BDigest"/><ref name="SACBee"/><ref name="CNN0409">{{cite news|url=https://money.cnn.com/2009/04/23/news/economy/california.reut/index.htm |title=California adopts first-ever low-carbon fuel rule |publisher=[[CNN News]] |date=April 23, 2009 |access-date=April 28, 2009 |url-status=dead |archive-url=https://web.archive.org/web/20090427132230/https://money.cnn.com/2009/04/23/news/economy/california.reut/index.htm |archive-date=April 27, 2009 }}</ref>

A similar controversy arose after the U.S. Environmental Protection Agency (EPA) published on May 5, 2009, its notice of proposed rulemaking for the new [[Renewable Fuel Standard]] (RFS).<ref>{{cite web |url=http://www.epa.gov/otaq/renewablefuels/#regulations |title=Renewable Fuel Standard Program (RFS2): Notice of Proposed Rulemaking |publisher=US Environmental Protection Agency |date=May 5, 2009 |access-date=May 6, 2009}}</ref><ref name="LAT0609">{{cite news|url=https://www.latimes.com/news/nationworld/nation/la-na-corn-ethanol6-2009may06,0,2321568.story |title=New standards could cut tax breaks for corn-based ethanol |newspaper=[[Los Angeles Times]] |date=May 6, 2009 |access-date=May 6, 2009 |author= Jim Tankersley}}</ref><ref name="Guardian0609">{{cite news |url=https://www.theguardian.com/world/2009/may/06/obama-ethanol-green-biofuel|title=Barack Obama's $1.8bn vision of greener biofuel|author= Suzanne Goldenberg |newspaper=The Guardian |date=May 6, 2009 |access-date=May 6, 2009 | location=London}}</ref> EPA's proposal included the [[carbon footprint]] from indirect land-use changes.<ref>{{cite web |url=http://earth2tech.com/2009/05/05/corn-ethanol-crew-cries-foul-over-epa-emissions-ruling/ |title=Corn Ethanol Crew Cries Foul Over EPA Emissions Ruling |work=earth2tech.com |author=Jennifer Kho |date=May 5, 2009 |access-date=May 6, 2009 |archive-date=May 9, 2009 |archive-url=https://web.archive.org/web/20090509091036/http://earth2tech.com/2009/05/05/corn-ethanol-crew-cries-foul-over-epa-emissions-ruling/ |url-status=dead }}</ref><ref>{{cite web |url=http://triangle.bizjournals.com/triangle/prnewswire/press_releases/national/California/2009/05/05/SPTU003 |title=Sugarcane Ethanol Industry Eager to Implement U.S. Renewable Fuel Standard |publisher=National Press Release |author=UNICA Press Release|date=May 5, 2009 |access-date=May 6, 2009}}</ref> On the same day, President [[Barack Obama]] signed a [[Presidential Directive]] with the aim to advance biofuel research and commercialization. The Directive asked a new Biofuels Interagency Working Group comprising the Department of Agriculture, EPA, and DOE,<ref name="WH0509"/><ref name="NYT0509"/> to develop a plan to increase flexible fuel vehicle use, assist in retail marketing and to coordinate infrastructure policies.

The group also was tasked to develop policy ideas for increasing investment in next-generation fuels, and for reducing biofuels' environmental footprint.<ref name="WH0509">{{cite web|url=https://obamawhitehouse.archives.gov/the_press_office/President-Obama-Announces-Steps-to-Support-Sustainable-Energy-Options/ |title=President Obama Announces Steps to Support Sustainable Energy Options, Departments of Agriculture and Energy, Environmental Protection Agency to Lead Efforts |date=May 5, 2009 |via=[[NARA|National Archives]] |work=[[whitehouse.gov]] |access-date=May 5, 2009 }}</ref><ref name="NYT0509">{{cite news|url=http://greeninc.blogs.nytimes.com/2009/05/05/white-house-steps-up-support-for-biofuels/ |title=White House Steps Up Support for Biofuels |newspaper=The New York Times |date=May 5, 2009 |access-date=May 5, 2009 |author= Matthew L. Wald}}</ref><ref name="Sciam0509">{{cite magazine|url=http://www.scientificamerican.com/article.cfm?id=obama-administration-pushes-biofuels |title=Obama Administration Prepares to Push Biofuels |magazine=Scientific American |date=May 5, 2009 |access-date=May 5, 2009 |author= Ben Geman}}</ref>

In December 2009 two lobbying groups, the [[Renewable Fuels Association]] (RFA) and Growth Energy, filed a lawsuit challenging LCFS's constitutionality. The two organizations argued that LCFS violates both the [[Supremacy Clause]] and the [[Commerce Clause]] of the [[US Constitution]], and "jeopardizes the nationwide market for ethanol."<ref name=WSJ1209>{{cite news|url=https://www.wsj.com/articles/SB126169282611304857|title=Ethanol Groups Sue California Over Low-Carbon Rule|newspaper=The Wall Street Journal|date=December 24, 2009|access-date=December 29, 2009 | first=Stephen | last=Power}}</ref><ref name=GCC1209>{{cite web|url=http://www.greencarcongress.com/2009/12/rfa-lcfs-20091225.html#more|title=Ethanol Groups File Suit Challenging Constitutionality of California Low Carbon Fuel Standard|publisher=Green Car Congress|date=December 25, 2009|access-date=December 29, 2009}}</ref> In a press release the associations announced that "If the United States is going to have a low carbon fuel standard, it must be based on sound science and it must be consistent with the U.S. Constitution".<ref>{{cite web|url=http://renewablefuelsassociation.cmail1.com/T/ViewEmail/y/9E510C2CBC9CF893/968C17640481D3A09A8E73400EDACAB4|title=Ethanol Groups Challenge Constitutionality of California LCFS|publisher=Renewable Fuels Association|date=December 24, 2009|access-date=December 29, 2009}}</ref>

On February 3, 2010, EPA finalized the Renewable Fuel Standard Program (RFS2) for 2010 and beyond.<ref>{{cite web|url=http://www.epa.gov/OMS/renewablefuels/|title=Renewable Fuel Standard Program (RFS2): Final Rule|publisher=U.S. Environmental Protection Agency|date=February 3, 2010|access-date=February 9, 2010}}</ref> EPA incorporated direct emissions and significant indirect emissions such as emissions from land use changes along with comments and data from new studies.<ref name=EPA2010/> Adopting a 30-year time horizon and a 0% discount rate<ref name=EPAfinal2010/> EPA declared that ethanol produced from corn starch at a new (or expanded capacity from an existing) natural gas-fired facility using approved technologies would be considered to comply with the 20% GHG emission reduction threshold.<ref name=EPA2010>{{cite web|url=http://www.epa.gov/OMS/renewablefuels/420f10007.htm#7|title=Greenhouse Gas Reduction Thresholds|publisher=U.S. Environmental Protection Agency|date=February 3, 2010|access-date=February 9, 2010}}</ref> Given average production conditions it expected for 2022, EPA estimated that corn ethanol would reduce GHGs an average of 21% compared to the 2005 gasoline baseline. A 95% confidence interval spans a 7-32% range reflecting uncertainty in the land use change assumptions.<ref name=EPAfinal2010/>

The following table summarizes the mean GHG emissions for ethanol using different feedstocks estimated by EPA modelling and the range of variations considering that the main source of uncertainty in the life cycle analysis is the GHG emissions related to international land use change.<ref name=EPAFinal2010/>

{| class="wikitable" style="margin: 1em auto 1em auto"
! colspan="4" style="text-align:center; background:#cfc;"| U.S. Environmental Protection Agency<br />Life cycle year 2022 [[GHG emissions]] reduction results for RFS2 final rule<ref name=EPAFinal2010>{{cite web|url=http://www.epa.gov/otaq/renewablefuels/420r10006.pdf |title=Renewable Fuel Standard Program(RFS2) Regulatory Impact Analysis |publisher=U.S. Environmental Protection Agency |date=February 2010 |access-date=February 12, 2010 |url-status=dead |archive-url=https://web.archive.org/web/20110202202402/http://www.epa.gov/otaq/renewablefuels/420r10006.pdf |archive-date=February 2, 2011 }} ''See'' pp. 480 and 489 and Tables 2.6-1 to 2.6–11.</ref><br />(includes direct and indirect land use change effects and a 30-year payback [[Time horizon|period]] at a 0% [[discounted cash flow|discount rate]])
|- 
! style="background:#cfc;"| Renewable fuel pathway<br />(for U.S. consumption) || style="background:#cfc;"| Mean<br />GHG emission<br />reduction<sup>(1)</sup> || style="background:#cfc;"| GHG emission<br />reduction<br />95% confidence<br />interval<sup>(2)</sup>|| style="background:#cfc;"|Assumptions/comments
|-
|[[Corn ethanol]]||{{center|21%}}||{{center|7–32%}} ||New or expanded [[natural gas]] fired dry mill plant, 37% wet and 63% dry [[distillers grains|DGS]] it produces, and employing corn oil fractionation technology.
|-
|Corn [[biobutanol]]||{{center|31%}}||{{center|20–40%}} ||Natural gas fired dry mill plant, 37% wet and 63% dry DGS it produces, and employing corn oil fractionation technology.
|-
| Cellulosic ethanol from switchgrass ||{{center|110%}}||{{center|102–117%}} ||Ethanol produced using the biochemical process.
|-
| Cellulosic ethanol from [[corn stover]] ||{{center|129%}}||{{center|No [[ILUC]]}} ||Ethanol produced using the biochemical process. Ethanol produced from agricultural residues does not have any indirect land use emissions.
|-
| colspan="4" |<small>Notes: (1) Percent reduction in lifecycle GHG emissions compared to the average lifecycle GHG for gasoline or diesel sold or distributed as transportation fuel in 2005.<br />(2) Confidence range accounts for uncertainty in the types of land use change assumptions and the magnitude of resulting GHG emissions.</small>
|}

====Water footprint====
Water-related concerns relate to water supply and quality, and include availability and potential overuse, pollution, and possible contamination by [[fertilizer]]s and [[pesticide]]s. Several studies concluded that increased ethanol production was likely to result in a substantial increase in water pollution by fertilizers and pesticides, with the potential to exacerbate [[eutrophication]] and [[Hypoxia (environmental)|hypoxia]], particularly in the [[Chesapeake Bay]] and the [[Gulf of Mexico]].<ref name=Wfootprint2010>{{cite journal|title=The water footprint of biofuel production in the USA |last1=Powers |first1=Susan E |last2=Dominguez-Faus |first2=Rosa |last3=Alvarez |first3=Pedro JJ |date=March 2010 |journal=Biofuels |volume=1 |issue=2 |pages=255–260 |doi=10.4155/BFS.09.20 |s2cid=130923687 }}{{dead link|date=June 2017 |bot=InternetArchiveBot |fix-attempted=yes }}</ref><ref name=NRCWater>{{Cite book | author=United States National Research Council, Committee on Water Implications of Biofuels Production in the United States |title = Water Implications of Biofuels Production in the United States| year = 2008 | publisher = [[The National Academy Press]], Washington, D.C.| isbn = 978-0-309-11361-8}}</ref><ref name=Wfootprint2009/><ref name=SFGate070610/>

Growing feedstocks consumes most of the water associated with ethanol production. Corn consumes from {{convert|500|-|2000|L}} of water per liter of ethanol, mostly for [[evapotranspiration]].<ref name=Wfootprint2010/> In general terms, both corn and switchgrass require less irrigation than other fuel crops. Corn is grown mainly in regions with adequate rainfall. However, corn usually needs to be irrigated in the drier climates of [[Nebraska]] and eastern [[Colorado]]. Further, corn production for ethanol is increasingly taking place in areas requiring irrigation.<ref name=Wfootprint2010/> A 2008 study by the [[United States National Research Council|National Research Council]] concluded that "in the longer term, the likely expansion of cellulosic biofuel production has the potential to further increase the demand for water resources in many parts of the United States. Biofuels expansion beyond current irrigated agriculture, especially in dry western areas, has the potential to greatly increase pressure on water resources in some areas."<ref name=NRCWater/>

A 2009 study estimated that irrigated corn ethanol implied water consumption at between {{convert|50|USgal/mi|L/km|abbr=on}} and {{convert|100|USgal/mi|L/km|abbr=on}} for U.S. vehicles. This figure increased to {{convert|90|USgal/mi|L/km|abbr=on}} for [[sorghum]] ethanol from Nebraska, and {{convert|115|USgal/mi|L/km|abbr=on}} for Texas sorghum. By contrast, an average U.S. car effectively consumes between {{convert|0.2|USgal/mi|L/km|abbr=on}} to {{convert|0.5|USgal/mi|L/km|abbr=on}} running on gasoline, including extraction and refining.<ref name=Wfootprint2009>{{cite journal|title=The Water Footprint of Biofuels: A Drink or Drive Issue?|last2=Powers|first4=Pedro J.|first2=Susan E.|last1=Dominguez-Faus|last4=Alvarez|first1=Rosa|last3=Alvarez |first3=Pedro JJ |year=2009|journal=Environmental Science and Technology|volume=43|issue=9|pages=3005–3010|doi=10.1021/es802162x|pmid=19534106|bibcode=2009EnST...43.3005D|doi-access=}}</ref>

In 2010 RFA argued that more efficient water technologies and pre-treated water could reduce consumption.<ref name=RFA2010>{{cite web|url=http://www.ethanolrfa.org/page/-/objects/pdf/outlook/RFAoutlook2010_fin.pdf?nocdn=1 |title=2010 Ethanol Industry Outlook: Climate of Opportunity |publisher=Renewable Fuels Association |year=2010 |access-date=July 28, 2010 |url-status=dead |archive-url=https://web.archive.org/web/20110718131036/http://www.ethanolrfa.org/page/-/objects/pdf/outlook/RFAoutlook2010_fin.pdf?nocdn=1 |archive-date=July 18, 2011 }} ''See pages 5, 14–15, and 1''9.</ref> It further claimed that [[non-conventional oil]] "sources, such as [[tar sands]] and [[oil shale]], require far more water than conventional petroleum extraction and refining."<ref name=RFA2010/>

[[File:Dead Zone NASA NOAA.jpg|thumb|[[Dead zone (ecology)|Dead zone]] in the Gulf of Mexico.]]
U.S. standard agricultural practices for most crops employ fertilizers that provide [[nitrogen]] and [[phosphorus]] along with [[herbicide]]s, [[fungicide]]s, [[insecticide]]s, and other pesticides.{{Citation needed|date=January 2021}}

Some part of these chemicals leaves the field. Nitrogen in forms such as [[nitrate]] (NO<sub>3</sub>) is highly soluble, and along with some pesticides infiltrates downwards toward the [[water table]], where it can migrate to water wells, rivers and streams. A 2008 National Research Council study found that regionally the highest stream concentrations occur where the rates of application were highest, and that these rates were highest in the [[Corn Belt]]. These flows mainly stem from corn, which as of 2010 was the major source of total nitrogen loading to the [[Mississippi River]].<ref name=NRCWater/>

Several studies found that corn ethanol production contributed to the worsening of the [[Dead zone (ecology)#Gulf of Mexico|Gulf of Mexico dead zone]]. The nitrogen [[wiktionary: leach|leached]] into the Mississippi River and out into the Gulf, where it fed giant [[algae bloom]]s. As the [[algae]] died, it settled to the ocean floor and decayed, consuming oxygen and suffocating marine life, causing [[hypoxia (environmental)|hypoxia]]. This oxygen depletion killed [[shrimp]], [[crab]]s, [[worm]]s and anything else that could not escape, and affected important [[Shrimp fishery|shrimp fishing grounds]].<ref name=Wfootprint2010/><ref name=NRCWater/><ref name=SFGate070610>{{cite news|url=http://articles.sfgate.com/2010-07-06/news/21939174_1_dead-zone-ethanol-production-oil-spill|title=Dead zone in gulf linked to ethanol production|newspaper=San Francisco Chronicle|date=July 6, 2010|access-date=July 28, 2010 | first=Carolyn | last=Lochhead}}</ref>

=== Social implications ===

==== Effect on food prices ====
{{Main article|Food vs fuel}}
Some [[environmentalists]], such as [[George Monbiot]], expressed fears that the marketplace would convert crops to fuel for the rich, while the poor starved and biofuels caused environmental problems.<ref name="Times08"/><ref name="Monbiot">{{cite web|url=http://www.monbiot.com/archives/2004/11/23/feeding-cars-not-people/|title=Feeding Cars, Not People|author=George Monbiot|work=Monbiot.com|access-date=April 28, 2008|date=November 23, 2004}}</ref><ref>{{cite web|url=http://www.climnet.org/EUenergy/2006_EEB_BiofuelsStrategy.pdf|title=Biofuels no panacea|author=European Environmental Bureau|access-date=April 28, 2008|date=February 8, 2006|archive-url = https://web.archive.org/web/20080410052938/http://www.climnet.org/EUenergy/2006_EEB_BiofuelsStrategy.pdf |archive-date = April 10, 2008}}</ref><ref>{{cite web|url=http://www.planetark.com/dailynewsstory.cfm/newsid/32656/story.htm|title=Food Security Worries Could Limit China Biofuels|author=Planet Ark|access-date=April 28, 2008|date=September 26, 2005}}</ref><ref>{{cite web|url=http://www.greenpeace.org.uk/blog/climate/biofuels-green-dream-or-climate-change-nightmare-20070509|title=Biofuels: green dream or climate change nightmare|author=Greenpeace UK|access-date=April 28, 2008|date=May 9, 2007|url-status=dead|archive-url=https://web.archive.org/web/20080421113313/http://www.greenpeace.org.uk/blog/climate/biofuels-green-dream-or-climate-change-nightmare-20070509|archive-date=April 21, 2008}}</ref> The [[food vs fuel]] debate grew in 2008 as a result of the [[international community]]'s concerns regarding the [[2007–2008 world food price crisis|steep increase in food prices]]. In April 2008, [[Jean Ziegler]], back then [[United Nations Special Rapporteur]] on the Right to Food, repeated his claim that biofuels were a "crime against humanity",<ref>{{cite web|url=http://www1.folha.uol.com.br/folha/dinheiro/ult91u391866.shtml|title=ONU diz que biocombustíveis são crime contra a humanidade|publisher=Folha de Sao Pãulo Online|date=April 14, 2008|access-date=April 28, 2008|language=pt}}</ref><ref name="BBC_Brasilia">{{cite news|url=http://news.bbc.co.uk/2/hi/science/nature/7351766.stm|title=Brazil president defends biofuels|author=Emilio San Pedro
|work=BBC News|date=April 17, 2008|access-date=April 28, 2008}}</ref> echoing his October 2007 call for a 5-year ban for the conversion of land for the production of biofuels.<ref>{{cite news|url=https://www.independent.co.uk/environment/green-living/production-of-biofuels-is-a-crime-398066.html|date=October 27, 2007|title=Production of biofuels 'is a crime'|first=Edith|last=Lederer|newspaper=[[The Independent]]|access-date=April 22, 2008 | location=London}}</ref><ref>{{cite web|url=http://www.swissinfo.org/eng/front/detail/UN_rapporteur_calls_for_biofuel_moratorium.html?siteSect=105&sid=8305080&cKey=1192127505000&ty=st|title=UN rapporteur calls for biofuel moratorium|website=Swissinfo|date=October 11, 2007|access-date=May 1, 2008|archive-date=April 29, 2008|archive-url=https://web.archive.org/web/20080429202834/http://www.swissinfo.org/eng/front/detail/UN_rapporteur_calls_for_biofuel_moratorium.html?siteSect=105&sid=8305080&cKey=1192127505000&ty=st|url-status=dead}}</ref> Also in April 2008, [[World Bank]] President [[Robert Zoellick]] stated that "While many worry about filling their gas tanks, many others around the world are struggling to fill their stomachs. And it's getting more and more difficult every day."<ref>{{cite news|url=https://www.theguardian.com/business/2008/apr/11/worldbank.fooddrinks1|title=Poor go hungry while rich fill their tanks|author1=Larry Elliott |author2=Heather Stewart |newspaper=The Guardian|date= April 11, 2008|access-date=April 30, 2008 | location=London}}</ref><ref>{{cite news|url=https://www.washingtonpost.com/wp-dyn/content/story/2008/04/29/ST2008042903585.html|title=Siphoning Off Corn to Fuel Our Cars|date=April 30, 2008|newspaper=The Washington Post|author=Steven Mufson|access-date=April 30, 2008}}</ref><ref>{{cite news|url=http://www1.folha.uol.com.br/folha/bbc/ult272u391745.shtml|title=FMI e Bird pedem ação urgente contra alta alimentar|publisher=Folha de Sao Pãulo Online|date=April 13, 2008|access-date=April 28, 2008|language=pt}}</ref>
[[File:Combine-harvesting-corn.jpg|thumb|Corn is the main feedstock for the production of ethanol fuel in the U.S.]]
A July 2008 World Bank report<ref name=WorldBank0708>{{cite web|url=http://www-wds.worldbank.org/external/default/WDSContentServer/IW3P/IB/2008/07/28/000020439_20080728103002/Rendered/PDF/WP4682.pdf|title=A note on Rising Food Crisis|publisher=The World Bank|author=Donald Mitchell|date=July 2008|access-date=July 29, 2008}} Policy Research Working Paper No. 4682. "Disclaimer: This paper reflects the findings, interpretation, and conclusions of the authors, and do not necessarily represent the views of the World Bank"</ref> found that from June 2002 to June 2008 "biofuels and the related consequences of low grain stocks, large land use shifts, speculative activity and export bans" accounted for 70–75% of total price rises. The study found that higher oil prices and a weak dollar explain 25–30% of total price rise. The study said that "large increases in biofuels production in the United States and Europe are the main reason behind the steep rise in global food prices."<ref name=Veja2807>{{Cite news|url=http://vejaonline.abril.com.br/notitia/servlet/newstorm.ns.presentation.NavigationServlet?publicationCode=1&pageCode=1&textCode=145568&date=currentDate|title=Etanol não influenciou nos preços dos alimentos|work=Veja|language=pt|date=July 28, 2008|access-date=July 29, 2008|url-status=dead|archive-url=https://web.archive.org/web/20090210110110/http://vejaonline.abril.com.br/notitia/servlet/newstorm.ns.presentation.NavigationServlet?publicationCode=1&pageCode=1&textCode=145568&date=currentDate|archive-date=February 10, 2009}}</ref><ref name=Reuters>{{cite news|url=http://www.alertnet.org/thenews/newsdesk/N28615016.htm|title=Biofuels major driver of food price rise-World Bank|agency=Reuters|date=July 28, 2008|access-date=July 29, 2008|archive-date=August 29, 2008|archive-url=https://web.archive.org/web/20080829070302/http://www.alertnet.org/thenews/newsdesk/N28615016.htm|url-status=dead}}</ref> The report argued that increased production of biofuels in these developed regions was supported by subsidies and tariffs, and claimed that without such policies, food price increases worldwide would have been smaller. It also concluded that Brazil's sugarcane ethanol had not raised sugar prices significantly, and recommended that both the U.S. and E.U. remove tariffs, including on many African countries.<ref name=WorldBank0708/>

An RFA rebuttal said that the World Bank analysis was highly subjective and that the author considered only "the impact of global [[food prices]] from the weak dollar and the direct and indirect effect of high petroleum prices and attribute[d] everything else to biofuels."<ref>{{cite web|url=http://www.ethanolrfa.org/objects/documents/1812/lecg_work_bank_critique.pdf |title=Critique of World Bank Working Paper "A Note of Rising Food Prices" |author=John M. Urbanchuk |date=July 11, 2008 |publisher=Renewable Fuel Association |access-date=July 29, 2008 |url-status=dead |archive-url=https://web.archive.org/web/20080819214631/http://www.ethanolrfa.org/objects/documents/1812/lecg_work_bank_critique.pdf |archive-date=August 19, 2008 }}</ref>

A 2010 World Bank study concluded that its previous study may have overestimated the impact, as "the effect of biofuels on food prices has not been as large as originally thought, but that the use of commodities by financial investors (the so-called 'financialization of commodities') may have been partly responsible for the 2007/08 spike."<ref name=WorldBank0710>{{cite web|url=http://www-wds.worldbank.org/external/default/WDSContentServer/IW3P/IB/2010/07/21/000158349_20100721110120/Rendered/PDF/WPS5371.pdf|title=Placing the 2006/08 Commodity Price Boom into Perspective|publisher=World Bank|author1=John Baffes |author2=Tassos Haniotis |date=July 2010|access-date=August 9, 2010}} Policy Research Working Paper 5371</ref>

A July 2008 [[OECD]] economic assessment<ref name=OECD0708>{{cite web|url=http://www.oecd.org/dataoecd/19/62/41007840.pdf |title=Economic Assessment of Biofuel Support Policies |author1=Directorate for Trade |author2=Agriculture, OECD |publisher=OECD |date=July 16, 2008 |access-date=August 1, 2008 |url-status=dead |archive-url=https://web.archive.org/web/20080718170926/http://www.oecd.org/dataoecd/19/62/41007840.pdf |archive-date=July 18, 2008 }} "Disclaimer: This work was published under the responsibility of the Secretary-General of the OECD. The views expressed and conclusions reached do not necessarily correspond to those of the governments of OECD member countries."</ref> agreed about the negative effects of subsidies and trade restrictions, but found that the impact of biofuels on food prices was much smaller. The OECD study found that existing biofuel support policies would reduce greenhouse gas emissions by no more than 0.8 percent by 2015. It called for more open markets in biofuels and feedstocks to improve efficiency and lower costs. The OECD study concluded that "current biofuel support measures alone are estimated to increase average wheat prices by about 5 percent, maize by around 7 percent and vegetable oil by about 19 percent over the next 10 years."<ref name=OECDweb08>{{cite web|url=http://www.oecd.org/document/28/0,3343,en_2649_37401_41013916_1_1_1_1,00.html|title=Biofuel policies in OECD countries costly and ineffective, says report |author1=Directorate for Trade |author2=Agriculture, OECD |publisher=OECD|date=July 16, 2008|access-date=August 1, 2008}}</ref>

During the [[2008 financial crisis]] corn prices, fell 50% from their July 2008 high by October 2008, in tandem with other [[commodities]], including [[oil]], while corn ethanol production continued unabated. "Analysts, including some in the ethanol sector, say ethanol demand adds about 75 cents to $1.00 per bushel to the price of corn, as a rule of thumb. Other analysts say it adds around 20 percent, or just under 80 cents per bushel at current prices. Those estimates hint that $4 per bushel corn might be priced at only $3 without demand for ethanol fuel."<ref>{{cite news|url=http://uk.reuters.com/article/oilRpt/idUKN2338007820081023|title=Ethanol no longer seen as big driver of food price|author=Sam Nelson|work=Reuters UK|date=October 23, 2008|access-date=November 26, 2008}}</ref>

Reviewing eight years of actual implementation of the Renewable Fuel Standard, researchers from the University of Wisconsin found the standard increased corn prices by 30% and prices of other crops by 20%.<ref name=":0" />

==See also==
{{Portal|Energy}}
{{div col|colwidth=22em}}

*[[2007 U.S. Farm Bill]]
*[[2007–2008 world food price crisis]]
*[[Butanol fuel]]
*[[Common ethanol fuel mixtures]]
*[[E85 in the United States]]
*[[Ethanol fuel by country]]
*[[Ethanol fuel in Australia]]
*[[Ethanol fuel in Brazil]]
*[[Ethanol fuel in Hawaii]]
*[[Ethanol fuel in the Philippines]]
*[[Ethanol fuel in Sweden]]
*[[Indirect land use change impacts of biofuels]]
*[[Issues relating to biofuels]]
*[[List of renewable energy topics by country]]
*[[Low-carbon fuel standard]]
*[[Renewable energy in the United States]]
*[[Renewable Fuel Standard]]
{{div col end}}

==Further reading==
* Duffield, James A., Irene M. Xiarchos, and Steve A. Halbrook, "Ethanol Policy: Past, Present, and Future", ''South Dakota Law Review''. 53 (no. 3, 2008), 425–53.

==References==
{{Reflist|2}}

==External links==

===U.S. government===
*[https://web.archive.org/web/20150518102307/http://www.ers.usda.gov/publications/err-economic-research-report/err102.aspx Effects of Increased Biofuels on the U.S. Economy in 2022], U.S. Department of Agriculture, October 2010.
*[http://www.afdc.energy.gov/afdc/data/fuels.html U.S. Ethanol Fuel: Data, Analysis and Trends], U.S. Department of Energy
*[http://www.cbo.gov/ftpdocs/114xx/doc11477/07-14-Biofuels.pdf Using Biofuel Tax Credits to Achieve Energy and Environmental Policy Goals], [[Congressional Budget Office]], July 2010.

===International organizations===
*[https://web.archive.org/web/20091122133933/http://www.unep.fr/scp/rpanel/pdf/Assessing_Biofuels_Full_Report.pdf Towards Sustainable Production and Use of Resources: Assessing Biofuels] by the [[United Nations Environment Programme]], October 2009.
*[https://web.archive.org/web/20080516004927/http://econ.worldbank.org/WBSITE/EXTERNAL/EXTDEC/EXTRESEARCH/EXTWDRS/EXTWDR2008/0%2C%2CcontentMDK%3A21501336~pagePK%3A64167689~piPK%3A64167673~theSitePK%3A2795143%2C00.html World Bank, Biofuels: The Promise and the Risks. World Development Report 2008: Agriculture for Development]

===Other sources===
*[http://www.ethanolrfa.org Renewable Fuels Association web site]
*[https://web.archive.org/web/20050519140943/http://petroleum.berkeley.edu/papers/patzek/CRPS416-Patzek-Web.pdf Thermodynamics of the Corn-Ethanol biofuel cycle, T.Patzek]
{{World topic|Ethanol fuel in|noredlinks=yes}}
{{DEFAULTSORT:Ethanol Fuel In The United States}}
[[Category:Biofuel in the United States]]
[[Category:Ethanol fuel]]
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