The Renewable Fuel Standard (RFS): An Overview

Contents

• Introduction
• The Statute
• Statutory Compliance
• The 2019 Proposed Rule
• The 2018 Final Rule
• RFS Implementation Issues
• Administering Agency
• Qualifying Biofuels
• Cellulosic Biofuel Production
• Blend Wall
• Other Factors
• Congressional Issues

Summary

The Renewable Fuel Standard (RFS) requires U.S. transportation fuel to contain a minimum volume of renewable fuel. The RFS—established by the Energy Policy Act of 2005 (P.L. 109-58; EPAct05) and expanded in 2007 by the Energy Independence and Security Act (P.L. 110-140; EISA)—began with 4.0 billion gallons of renewable fuel in 2006 and aims to ascend to 36.0 billion gallons in 2022. The Environmental Protection Agency (EPA) determines the volume amounts after 2022.

The total renewable fuel statutory target consists of both conventional biofuel and advanced biofuel. Since 2014, the total renewable fuel statutory target has not been met, with the advanced biofuel portion falling below the statutory target by a large margin since 2015. Going forward, it is unlikely that the United States will meet the total renewable fuel target as outlined in statute.

EPA administers the RFS and is responsible for several tasks. For instance, within statutory criteria EPA evaluates which renewable fuels are eligible for the RFS program. Also, EPA establishes the amount of renewable fuel that will be required for the coming year based on fuel supply and other conditions (waiver authority in the statute allows the EPA Administrator to reduce the statutory volumes given certain conditions). Further, EPA now has the option to "reset" the RFS whereby it can modify the fuel volumes required for future years if certain conditions are met. EPA monitors compliance for the RFS using a system of tradable credits referred to as renewable identification numbers (RINs).

Some stakeholders have concerns about various facets of the RFS. These concerns include

• the costs incurred by some stakeholders (e.g., refiners) in order to comply with the mandate,
• the use of small refinery exemptions,
• whether the mandate has produced an environmental benefit (e.g., greenhouse gas emission reduction), and
• the pace at which some advanced biofuel pathways are approved for the RFS.

Congress has expressed ongoing interest in the RFS, particularly as the mandate relates to other legislative efforts (e.g., Reid Vapor Pressure requirements for ethanol-gasoline fuel blends containing greater than 10% ethanol, a national octane standard) and about oversight of the RIN market, among other things. Some proclaim it is time to amend or repeal the RFS, while others contend the best course of action is to maintain the status quo.

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Introduction

Established by Congress as an amendment to the Clean Air Act, the Renewable Fuel Standard (RFS) mandates that U.S. transportation fuel contain a minimum volume of biofuel.¹ The mandated minimum volume increases annually and must be met using both conventional biofuel (e.g., cornstarch ethanol) and advanced biofuel (e.g., cellulosic ethanol). For a renewable fuel to be applied toward the mandate, it must be used for certain purposes (transportation fuel, jet fuel, or heating oil) and meet certain environmental and biomass feedstock criteria.

A variety of factors (e.g., infrastructure, technology, and limited federal assistance) have led to challenges in meeting the total volume requirement established by Congress. These challenges have included a lack of cellulosic biofuel production and delays by the U.S. Environmental Protection Agency (EPA) in approving fuel pathways.² Further, it is not clear how changes in gasoline consumption and fluctuating crude oil and gasoline prices will impact the biofuel industry. It is also unclear how the program will fare if EPA implements the "reset" provision of the statute, which allows the agency to modify the volumes required for future years (starting in 2016) if certain conditions are met. And, some stakeholders have expressed concern about the transparency of the market whereby credits are traded to demonstrate compliance with the mandate.³ Lastly, there is concern by some that the Trump Administration's issuance of multiple small refinery waivers is adversely affecting biofuel demand.⁴

Although there are challenges, two fuel categories have consistently met their statutory targets: conventional biofuel and biomass-based diesel.⁵ Also, since 2014, two advanced biofuel pathways—renewable compressed natural gas and renewable liquefied natural gas—have constituted the majority of the cellulosic biofuel volume target established by EPA.⁶

Challenges in implementing the RFS have led to scrutiny of the program in Congress and to court rulings on EPA's regulations.^7,8 Largely due to concerns about the implementation and feasibility of the RFS, some Members of Congress have expressed their perspectives on EPA's proposed and final rules, EPA's implementation of the program, and questioned whether to amend or repeal the RFS or whether the best course is to maintain the status quo.⁹

This report provides a basic description of the RFS, including some of the widely discussed policy issues related to it.¹⁰

The Statute

The RFS was established by the Energy Policy Act of 2005 (P.L. 109-58; EPAct05) and expanded in 2007 by the Energy Independence and Security Act (P.L. 110-140; EISA). The RFS mandate requires that transportation fuel sold or introduced into commerce in the United States contain an increasing volume of a predetermined suite of renewable fuels. The statute required 4.0 billion gallons of renewable fuel in 2006, ascending to 36.0 billion gallons required in 2022, with EPA determining the volume amounts after 2022 in future rulemakings. The statute centers on four renewable fuel categories—conventional biofuel, advanced biofuel, cellulosic biofuel, and biomass-based diesel—each with its own target volume.¹¹

The total renewable fuel requirement for the RFS is met with the combination of fuels from two renewable fuel categories: conventional biofuel and advanced biofuel. Further, the requirement for advanced biofuel, in general, can be met with the combination of three types of advanced biofuel: cellulosic biofuel, biomass-based diesel, and other advanced biofuels. To date, the total annual volumes required have been met mostly with conventional biofuel (e.g., cornstarch ethanol). Beginning in 2015, the mandate capped the conventional biofuel volume amounts while increasing the requirement of advanced biofuels. For instance, the statutory RFS total advanced biofuel requirement increases over time from approximately 7% of the RFS in 2010 to 58% of the RFS in 2022.¹²

A key part of the statutory definition of each fuel category is whether the fuel achieves certain greenhouse gas (GHG) reductions relative to gasoline and diesel fuel. Each fuel is assigned a lifecycle GHG emission threshold (in proportion to baseline lifecycle GHG emissions for gasoline and diesel).¹³ For example, a fuel must achieve at least a 50% GHG reduction to be considered an advanced biofuel, at least a 60% reduction to be considered a cellulosic biofuel, and at least a 50% reduction to be considered biomass-based diesel. Similarly, biofuel from new facilities—those built after enactment of the 2007 law—must achieve at least a 20% GHG reduction to qualify as a conventional renewable fuel.¹⁴

Statutory Compliance

EPA regulates compliance with the RFS using a tradable credit system.¹⁵ Obligated parties¹⁶ (generally, refiners) submit credits—called renewable identification numbers (RINs)¹⁷—to EPA that equal the number of gallons in their annual obligation.¹⁸ This annual obligation, referred to as the renewable volume obligation (RVO), is the obligated party's total gasoline and diesel sales multiplied by the annual renewable fuel percentage standards announced by EPA.¹⁹ RINs are valid for use in the year they are generated and the following year.²⁰ Obligated parties may carry a deficit from one year to the next, but in the year following the deficit, the obligated party must meet compliance for that year's renewable fuel volume requirement and purchase or generate enough credits to satisfy the deficit from the previous year.²¹ RINs may be used by the party that generates them or they may be traded with other parties. The EPA Moderated Transaction System (EMTS) is used to register RIN transactions.

Different biofuels are not treated equally within the RFS, meaning that some biofuels can be used to meet the annual standard for multiple RFS categories.²² The categories are nested within each other, such that some fuels qualify for multiple categories (e.g., cellulosic ethanol), while others (mainly cornstarch ethanol) may only be used to meet the overall RFS but not the advanced category or its nested subcategories. For example, a gallon of cellulosic biofuel may be used to meet the cellulosic biofuel mandate, the advanced biofuel mandate, and the total renewable fuel, possibly making it a more highly valued fuel.²³

In addition, some biofuels generate more RINs per volume than others because of the difference in the fuel's energy content. This difference is accounted for by a metric referred to as the equivalence value (EV) of the biofuel.²⁴ The EV of a renewable fuel represents the number of gallons that can be claimed for compliance purposes for every physical gallon of renewable fuel used, and it is generally the ratio of the energy content of a gallon of the fuel to a gallon of ethanol. For example, because biodiesel has an EV of 1.5 when being used as an advanced biofuel,²⁵ 1,000 physical gallons of biodiesel would equal 1,500 RIN gallons of advanced biofuels.

The 2019 Proposed Rule

EPA released the proposed rule for the RFS for 2019 on June 26, 2018.²⁶ The rule proposes 19.88 billion gallons of total renewable fuel for 2019—approximately 8 billion gallons less than what is identified in statute (28.00 billion gallons for 2019) (see Table 1). Similar to previous years, the advanced biofuel volume requirement and the cellulosic biofuel volume requirement would both be reduced, while the conventional biofuel volume requirement would remain at 15.00 billion gallons. EPA proposes to use the cellulosic waiver authority to reduce the advanced biofuel volume requirement and the cellulosic biofuel volume requirement. Additionally, EPA requests comment on RIN market operations, specifically on the potential impact that "specific potential regulatory changes could have on the RIN market, positively or negatively, as well as on any other potential regulatory changes commenters may recommend to address perceived vulnerabilities in the RIN market."²⁷ EPA does not discuss a potential reset of the RFS.

The 2018 Final Rule

EPA released the final rule for the RFS for 2018 on November 30, 2017.²⁸ The rule calls for 19.29 billion gallons of total renewable fuel for 2018—a slight increase from the 19.28 billion gallons required in 2017 (see Table 1). The volume requirements set by EPA for 2018 for total renewable fuel, advanced biofuel, and cellulosic biofuel are all less than the volumes called for in statute. EPA used the cellulosic waiver authority to reduce the statutory volumes. EPA reports "the shortfall in cellulosic biofuels has made the volume targets established by Congress for 2018 for advanced biofuels and total renewable fuels beyond reach."²⁹ Also, EPA estimates there are 2.22 billion carryover RINs available.³⁰ EPA reports it did not set the 2018 renewable fuel volume requirements with the intention or expectation that there would be a drawdown of the carryover RINs.³¹

EPA set the biomass-based diesel 2019 volume requirement at 2.1 billion gallons, the same volume required for 2018. EPA reports the advanced biofuel requirement has proven in past years to incentivize biomass-based diesel supply above what the biomass-based diesel requirement has called for.³² Further, EPA acknowledges the uncertainty surrounding the availability of the biodiesel tax credit and the Department of Commerce's preliminary determination to establish countervailing duties on imported biodiesel.³³ Biomass-based diesel is the predominant biofuel used to satisfy the advanced biofuel portion of the mandate. Previously, it has been used to backfill the overall advanced biofuel requirement if another advanced biofuel fell short (e.g., cellulosic biofuel).

Lastly, in its response to comments regarding the rule, EPA reports comments about the "reset rule" are beyond the scope of the 2018 rulemaking.³⁴

RFS Implementation Issues

Implementation of the RFS has been complex, and compliance with some of its parts has been challenging, according to some stakeholders. This section briefly explains some of the general issues and challenges with implementing the RFS.

Administering Agency

EPA administers the RFS.³⁵ This responsibility includes evaluating renewable fuel pathways eligible for the RFS.³⁶ In addition, EPA is required to evaluate the ability of the biofuel industry to produce enough fuel to meet the annual volume standard, release an annual volume standard based on its research findings,³⁷ and ensure that annual compliance by obligated parties is met. All of the above must be completed annually, taking into consideration comments from other government agencies, the public, and, recently, court decisions. These responsibilities could be viewed as a significant addition to EPA's regulatory workload and have required EPA to develop new capabilities to carry them out.

For several years following the 2010 issuance of the amended RFS final rule,³⁸ EPA had difficulty projecting certain volume requirements (e.g., cellulosic biofuels). One of the concerns some have raised is the accuracy of EPA's projections. Based on these projections, EPA has used its waiver authority to set annual volume requirements for cellulosic biofuel, total advanced biofuel, and total renewable fuel different from what was stated in the statute.³⁹ Legal challenges have been brought against the EPA regarding some of these annual fuel volume projections. For instance, the American Petroleum Institute objected to EPA's 2012 cellulosic biofuel production projection, among other things, and challenged it in court. The federal court vacated the 2012 cellulosic biofuel standard and provided principles for EPA to apply to future annual projections.⁴⁰ Likewise, Americans for Clean Energy and other petitioners challenged various aspects of the final rule that set the volume requirements and projections for 2014-2016 and 2017 for biomass-based diesel, including EPA's interpretation of "inadequate domestic supply" in exercising its general waiver authority to reduce the total volume requirements. The D.C. Circuit Court vacated EPA's 2016 total renewable fuel volume requirement and remanded the 2015 final rule to EPA for reconsideration consistent with the court's decision.⁴¹

Another issue for EPA is the timing of the annual announcement of the renewable fuel volume requirements.⁴² The 2018 and 2017 final rules, issued in late November, adhere to the statutory schedule. However, the previous final rule, issued in late 2015, covered three years—2014, which had completely passed; 2015, which was almost done; and 2016.⁴³ A lack of timely rulemaking combined with inaccurate volume projections could affect private investment, according to some stakeholders.⁴⁴ An additional concern is the amount of time it takes the agency to approve new fuel pathways and register new facilities.⁴⁵

Lastly, the final rule for 2014 through 2016 triggered the "reset" provision of the RFS for the advanced biofuel and cellulosic biofuel categories.⁴⁶ If the proposed total renewable fuel volume amount for 2019 of 19.88 billion gallons is finalized (or a volume amount greater than a 20% reduction from the statutory target), the "reset" will be triggered for the total renewable fuel category. This would equate to three of the four renewable fuel categories identified in statute as capable of being "reset" by the EPA Administrator. The reset provision gives the EPA Administrator authority to adjust the applicable volumes of the RFS for future years starting in 2016 if certain conditions are met.⁴⁷ How EPA implements this provision will affect renewable fuel production and use.⁴⁸

Qualifying Biofuels

Some have had difficulty understanding which biofuel is eligible for each part of the mandate.⁴⁹ As noted above, there are a number of nested categories within the RFS; a fuel may qualify as a biofuel for one or more portions of the mandate.⁵⁰ Difficulty in understanding which advanced biofuels qualify for the RFS can lead to challenges in determining how compliance is being met.

Not all fuels from a renewable source are eligible under the RFS. The RFS operates as a biofuel standard, with priority assigned to liquid transportation fuels from biomass feedstocks.⁵¹ Other renewable sources (e.g., wind) do not qualify. Notably, imported biofuels (e.g., Brazilian sugarcane ethanol) that meet the biomass feedstock qualifications and GHG reduction thresholds are eligible to meet the RFS volume requirements. Before a fuel can generate RFS RINs however, that fuel pathway must be approved by EPA, a process that can take a considerable amount of time, according to some stakeholders.⁵²

Lastly, some might think the RFS is a biofuel production mandate. The statutory language does not mandate the production of biofuels; rather, it mandates the use of biofuel. However, it could be argued that it is difficult to use a fuel that is not being produced and that the RFS therefore indirectly creates a demand for certain biofuels and thus stimulates their production.

Cellulosic Biofuel Production

By statute, cellulosic biofuel is targeted to comprise approximately 44% of the total renewable fuel mandate in 2022. However, the annual cellulosic biofuel production volume established by Congress is not being met. Actual cellulosic biofuel production volumes (e.g., cellulosic ethanol) are below the expectations from when the law was passed. For instance, in 2017, the statute required 5.55 billion gallons of cellulosic biofuel. Actual production was approximately 252 million gallons (roughly 4.6% of the statutory requirement), of which 95% was renewable compressed or liquefied natural gas.⁵³ This shortfall is due to several factors, including lack of private investment, technology setbacks, and uneven support from the federal government.⁵⁴ These factors, coupled with the fact that annual volumes in the statute were established when market conditions for raising investment capital for new biofuel technologies were more favorable, may indicate unrealistic targets for some advanced biofuels for the near future. These production limitations have raised questions about whether the statutory cellulosic biofuel volumes are attainable.

Blend Wall

The "blend wall"—the upper limit to the total amount of ethanol that can be blended into U.S. gasoline and still maintain automobile performance and comply with the Clean Air Act—has been viewed by many to be in direct conflict with the biofuel volumes mandated in the RFS.⁵⁵ Thus far, the largest volume being met under the RFS is for the nonadvanced (conventional) biofuel segment of the mandate, and this has been met mainly with cornstarch ethanol blended into gasoline. Due to a variety of factors, ethanol content in gasoline is generally limited to 10% (E10). With a relatively fixed supply of gasoline, the amount of ethanol that can be supplied this way is also limited. If the ethanol content of gasoline for the majority of vehicles remains at 10%, and given current fuel consumption rates, the conventional biofuel portion of the RFS abuts the line of just slightly requiring more ethanol than can technically be blended into gasoline.⁵⁶

Technically, the blend wall remains a concern, but it may not be as significant an impediment to immediate fuel consumption as previously considered by some. Indeed, EPA reports "the E10 blendwall is not the barrier that some stakeholders believe it to be."⁵⁷ Had the RFS mandates—for both conventional biofuel and advanced biofuel—come to fruition in the form of mostly ethanol, or had fuel consumption decreased further, the blend wall potentially could have led to a more serious discussion about the volume mandates. However, primarily due to the lack of cellulosic biofuel production, more time has been granted to address the blend wall and the scheduled levels of biofuels in the RFS.

Some recent developments could alleviate blend wall concerns in the near term. One option suggested by some is to blend higher levels of ethanol into conventional gasoline.⁵⁸ In 2010 EPA granted a Clean Air Act waiver that allows gasoline to contain up to 15% ethanol for use in model year 2001 and newer light-duty motor vehicles.⁵⁹ However, infrastructure and automobile warranty concerns along with the lack of a waiver to sell E15 during the summer months have precluded widespread offering and purchase of E15, gasoline blended with 10.5% to 15% ethanol.⁶⁰ Widespread use of E15 could potentially postpone the blend wall for a few years.

Another option to address the blend wall would be an aggressive push for the use of ethanol in flexible-fuel vehicles capable of using E85, a gasoline-ethanol blend containing 51% to 83% ethanol.⁶¹ There are infrastructure concerns with the use of E85. For example, the number of E85 fueling stations is limited.⁶² To help address these infrastructure issues, the U.S. Department of Agriculture (USDA) announced $100 million in matching grants in 2015 under its Biofuel Infrastructure Partnership.⁶³ The grants may be used for blender pumps, dedicated E15 or E85 pumps, and new storage tanks and related equipment associated with new facilities or additional capacity.

Other Factors

The RFS is not a stand-alone policy. It interacts with many factors that are not easily controlled. For example, cellulosic biofuel production, at a minimum, requires conversion technology, which itself requires technical expertise and time to ramp up to commercial scale. The large quantity of biomass feedstocks needed to produce such biofuels requires factors such as appropriate weather conditions and an expectation of stable markets for feedstock commodities. Further, some types of biofuel production thus far have been sensitive to the availability of tax incentives in order to be economically feasible (e.g., biodiesel).⁶⁴ Unexpected occurrences (e.g., drought, failed technology, tax incentive expiration) could potentially impact an entire industry, especially for some advanced biofuels that are nascent industries compared to conventional transportation fuels.

Congressional Issues

The RFS was established at a time when Congress foresaw the need to diversify the country's energy portfolio, strengthen the economy of rural communities by encouraging certain agricultural commodities that contribute to biofuel production, bolster U.S. standing in an emerging segment of the energy technology market, and protect the environment, among other objectives. The RFS was expanded more than 10 years ago. There are indications of which components of the RFS have progressed steadily toward meeting congressional intentions and which components have not.

The RFS is a policy with ambitious objectives. Policy questions surrounding future consideration of the RFS might include

• What should be the purposes of the RFS?
• Is the RFS properly designed to achieve those purposes?
• What happens when, and if, the RFS achieves its purposes?

At the outset, some would argue that the first question may seem straightforward; the RFS exists to introduce more biofuels into the transportation fuel market to achieve a number of transportation fuel supply and environmental objectives. However, it could be argued that the RFS exists to find another market for biomass feedstocks or to promote the economy of rural America (e.g., the construction of biofuel facilities that create jobs). Moreover, to the extent the RFS was designed to reduce U.S. dependence on foreign oil, and to the extent that hydraulic fracturing and the growth of unconventional oil and gas production have contributed to achieving that objective, is the RFS still needed for energy security purposes?⁶⁵ Likewise, the environmental impact of the RFS could be challenged, as the advanced biofuel component of the RFS—set to yield greater greenhouse gas emission reduction benefits—has missed the statutory targets by a large margin.⁶⁶

In examining whether the RFS is well designed to realize its purposes, some have inquired about the challenges in achieving the ambitious RFS targets, given concerns about the slow development of some advanced biofuels. Additionally, past delays in announcing final annual standards by EPA have led to significant uncertainty for biofuel producers, feedstock growers, and refiners. Whether the RFS should be eliminated, amended to address the current challenges in the program, or maintained in its current form is an ongoing question for Congress. A related question is whether the current provisions for EPA to waive various portions of the RFS mandates and to "reset" the RFS are sufficient to address the current supply challenges or whether the use of these waivers runs counter to the goals of the program.

The third question relates to interest by some Members of Congress in modifying or eliminating the conventional biofuel (e.g., cornstarch ethanol) portion of the mandate. If a segment of the biofuels industry has consistently reached the annual mandate set by Congress, is the mandate still necessary? Some contend that the conventional biofuel segment of the biofuels industry is well established, so it should not require a use mandate. In addition, it has been argued that a demand for conventional biofuels exists regardless of congressional involvement. Others counter that the RFS is needed to help lower GHG emissions and to assure that the biofuels industry continues to have access to a fuel distribution infrastructure that is largely controlled by petroleum interests.

Author Contact Information

Footnotes

1.	42 U.S.C. §7545(o).
2.	For more information on fuel pathways, see the "Administering Agency" section of this report.
3.	National Biodiesel Board, "NBB, Dozens of Biodiesel Companies Ask the President to Address RIN Values Without Undercutting the RFS and Rural America," press release, December 18, 2017.
4.	"Biofuel Makers Sue EPA over Small Refinery Waivers to Renewable Fuel Standard," S&P Global Platts, May 30, 2018.
5.	U.S. Environmental Protection Agency, 2017 Renewable Fuel Standard Data, June 27, 2018. Obligated parties have until March 31 to submit annual compliance reports for the prior year. §80.1451(a)(1) in the EPA RFS regulations.
6.	Ibid.
7.	The 115th Congress has held at least 11 hearings where the topics of biofuels and the Renewable Fuel Standard (RFS) were discussed: U.S. Congress, Senate Committee on Environment and Public Works, Legislative Hearing on S. 517, the Consumer and Fuel Retailer Choice Act, 115th Cong., June 14, 2017; and U.S. Congress, House Committee on Science, Space, and Technology, Joint Subcommittee on Environment and Subcommittee on Energy Hearing- Examining Advancements in Biofuels: Balancing Federal Research and Market Innovation, 115th Cong., July 25, 2017; U.S. Congress, Senate Committee on Agriculture, Nutrition, and Forestry, Nomination Hearing: Nomination of Stephen Censky and Ted McKinney, 115th Cong., September 19, 2017; U.S. Congress, House Committee on Energy and Commerce, Department of Energy Missions and Management Priorities, 115th Cong., October 12, 2017; U.S. Congress, House Committee on Energy and Commerce, The Mission of the U.S. Environmental Protection Agency, 115th Cong., December 7, 2017; U.S. Congress, Senate Committee on Environment and Public Works, The Impact of Federal Environmental Regulations and Policies on American Farming and Ranching Communities, 115th Cong., February 7, 2018; U.S. Congress, House Committee on Energy and Commerce, Subcommittee on Environment, The Future of Transportation Fuels and Vehicles, 115th Cong., March 7, 2018; U.S. Congress, House Committee on Ways and Means, Subcommittee on Tax Policy, Hearing on Post Tax Reform Evaluation of Recently Expired Tax Provisions, 115th Cong., March 14, 2018; U.S. Congress, House Committee on Energy and Commerce, Subcommittee on Environment, High Octane Fuels and High Efficiency Vehicles: Challenges and Opportunities, 115th Cong., April 13, 2018; U.S. Congress, House Committee on Energy and Commerce, Subcommittee on Environment, Advanced Biofuels Under the Renewable Fuel Standard: Current Status and Future Prospects, 115th Cong., May 22, 2018; U.S. Congress, House Committee on Energy and Commerce, Subcommittee on Environment, Background on Renewable Identification Numbers Under the Renewable Fuel Standard, 115th Cong., July 25, 2018. The 114th Congress held multiple hearings in which the RFS or renewable fuels were the major focus or a recurring topic of discussion. U.S. Congress, Senate Committee on Homeland Security and Governmental Affairs, Subcommittee on Regulatory Affairs and Federal Management, Re-examining EPA's Management of the Renewable Fuel Standard Program, hearing, 114th Cong., 1st sess., June 18, 2015; U.S. Congress, House Committee on Science, Space, and Technology, Subcommittee on Environment, The Renewable Fuel Standard: A Ten Year Review of Costs and Benefits, hearing, 114th Cong., 1st sess., November 3, 2015; U.S. Congress, Senate Committee on Environment and Public Works, Oversight of the Renewable Fuel Standard, hearing, 114th Cong., 2nd sess., February 24, 2016; U.S. Congress, House Committee on Oversight and Government Reform, Subcommittee on the Interior, Examining the Renewable Fuel Standard, hearing, 114th Cong., 2nd sess., March 16, 2016; U.S. Congress, House Committee on Energy and Commerce, Subcommittee on Energy and Power, Renewable Fuel Standard-Implementation Issues, hearing, 114th Cong., 2nd sess., June 22, 2016; U.S. Congress, House Committee on Science, Space, and Technology, Subcommittee on Energy, The EPA Renewable Fuel Standard Mandate, hearing, 114th Cong., 2nd sess., July 23, 2016. U.S. Congress, Senate Committee on Homeland Security and Governmental Affairs, Subcommittee on Regulatory Affairs and Federal Management, Examining Two GAO Reports Regarding the Renewable Fuel Standard, hearing, 114th Cong., 2nd sess., December 1, 2016.
8.	Since 2010, there have been numerous legal challenges regarding the U.S. Environmental Protection Agency's (EPA's) administration of the RFS. In some cases, courts have found against EPA's rules for various reasons; in others, courts have affirmed EPA's authority.
9.	Sen. Joni Ernst, "Iowa Farmers Deserve Honesty and Transparency from EPA on the Renewable Fuel Standard," press release, June 26, 2018; Sen. Heidi Heitkamp, "Heitkamp: New EPA RFS Proposal Boosts Ethanol, but Yearlong Sale of E15 and Refinery Waiver Issues Still Threaten ND Ag and Biofuel Producers," press release, June 26, 2018 ; Rep. Bob Goodlatte, "House Lawmakers: 2018 RFS Levels More of the Same," press release, November 30, 2017. Additionally, legislation has been proposed in the 115th Congress that would amend or repeal the RFS (e.g., H.R. 119, H.R. 776, H.R. 1314, and H.R. 1315).
10.	For additional discussion, see CRS Report R40155, Renewable Fuel Standard (RFS): Overview and Issues, by [author name scrubbed].
11.	The statute provides definitions for the four renewable fuels. Conventional biofuel is cornstarch ethanol. Advanced biofuel is renewable fuel, other than cornstarch ethanol, with lifecycle greenhouse gas emissions of at least 50% less than lifecycle greenhouse gas emissions from its gasoline or diesel counterpart. Cellulosic biofuel is renewable fuel derived from cellulose, hemicellulose, or lignin that is derived from renewable biomass, with lifecycle greenhouse gas emissions of at least 60% less than lifecycle greenhouse gas emissions from its gasoline or diesel counterpart. Biomass-based diesel is biodiesel or other renewable diesel with lifecycle greenhouse gas emissions of at least 50% less than lifecycle greenhouse gas emissions from its diesel counterpart.
12.	Calculations include the annual mandate required by statute in 2007 and do not take into account EPA's revision of the biofuel mandates for 2010 through 2018.
13.	For more information, see CRS Report R40460, Calculation of Lifecycle Greenhouse Gas Emissions for the Renewable Fuel Standard (RFS), by [author name scrubbed] and [author name scrubbed].
14.	New facilities are facilities that commence construction after December 19, 2007. 42 U.S.C. §7545 (o)(2)(A)(i).
15.	42 U.S.C. §7547(o)(5).
16.	EPA defines an obligated party as any refiner that produces gasoline or diesel fuel within the 48 contiguous states or Hawaii, or any importer of gasoline or diesel fuel into the 48 contiguous states or Hawaii during a compliance period.
17.	A renewable identification number (RIN) is a unique 38-character number that is issued (in accordance with EPA guidelines) by the biofuel producer or importer at the point of biofuel production or the port of importation. Each qualifying gallon of renewable fuel has its own unique RIN.
18.	For more information, see CRS Testimony TE10026, Background on Renewable Identification Numbers under the Renewable Fuel Standard, by [author name scrubbed].
19.	For 2018, the overall renewable fuel percentage standard is 10.67%, the advanced biofuel percentage standard is 2.37%, the biomass-based diesel percentage standard is 1.74%, and the cellulosic biofuel percentage standard is 0.159%. EPA, "Renewable Fuel Standard Program: Standards for 2018 and Biomass-Based Diesel Volume for 2019; Final Rule," 82 Federal Register, December 12, 2017.
20.	40 C.F.R. §80.1427(6)(i) in the EPA RFS regulations. Obligated parties may use RINS generated in the previous year to meet up to 20% of their current year exporter renewable volume obligation. EPA, "RFS Renewable Identification Number (RIN) Quality Assurance Program; Final Rule," 79 Federal Register, July 18, 2014.
21.	42 U.S.C. §7547(o)(5)(D).
22.	Although a gallon of a biofuel may be used to fulfill individual sub-requirements or the overall requirement, each gallon counts once against the overall renewable fuel use obligation.
23.	The value of any biofuel within the RFS depends on the RIN price at a given time. As different categories of RINs are used to meet the various standards, there is often a price difference between RINs (e.g., advanced biofuel RINs are generally more expensive than conventional biofuel RINs). However, there is no public market for RINs, so price data are difficult to obtain.
24.	40 C.F.R. §80.1415.
25.	All EVs are in relation to the energy content of ethanol. The EV for ethanol is 1.0. One gallon of biodiesel contains roughly 1.5 times the energy of one gallon of ethanol, and thus has an EV of 1.5.
26.	U.S. Environmental Protection Agency, "Renewable Fuel Standard Program: Standards for 2019 and Biomass-Based Diesel Volume for 2020; Proposed Rule," 83 Federal Register, July 10, 2018.
27.	EPA reports it is not proposing to make any such regulatory changes in this rulemaking.
28.	EPA, "Renewable Fuel Standard Program: Standards for 2018 and Biomass-Based Diesel Volume for 2019; Final Rule," 82 Federal Register, December 12, 2017.
29.	Ibid.
30.	Within limits, carryover RINs may be used to comply with the next year's mandate. EPA proposes to preserve the RINs to provide obligated parties with compliance flexibility.
31.	Ibid.
32.	Ibid.
33.	For more information on biodiesel tax incentives, see CRS Report R44990, Energy Tax Provisions That Expired in 2017 ("Tax Extenders"), by [author name scrubbed], [author name scrubbed], and [author name scrubbed] . For more information on the imports of biodiesel countervailing duty determinations, see U.S. Department of Commerce, U.S. Department of Commerce Issues Affirmative Final Countervailing Duty Determinations on Biodiesel from Argentina and Indonesia, November 9, 2017.
34.	U.S. Environmental Protection Agency, Renewable Fuel Standard Program—Standards for 2018 and Biomass-Based Diesel Volume for 2019: Response to Comments, EPA-420-R-17-007, December 2017.
35.	Although the RFS is administered by EPA, programs under other federal departments may indirectly assist biofuel production that may be used to meet the mandate. For example, the U.S. Department of Agriculture provides resources and support for biofuel feedstock development and supply (e.g., Biomass Crop Assistance Program) as well as biofuel infrastructure development (e.g., Rural Energy for America Program, Biorefinery Assistance Program, Biofuel Infrastructure Partnership, etc.).
36.	A fuel pathway consists of three components: a biomass feedstock, a biofuel production process, and a fuel type (e.g., ethanol made from cornstarch using a dry mill production process). The fuel pathway is assigned to a renewable fuel category (known by its D code provided in Table 1 of 40 C.F.R. §80.1426 in the RFS regulations) which signifies which RIN the biofuel is eligible for to be in compliance with the RFS. EPA maintains a list of approved fuel pathway and fuel pathway petitions on its website (https://www.epa.gov/renewable-fuel-standard-program/approved-pathways-renewable-fuel).
37.	Frequently, EPA has approved annual standards for some biofuels different from what was originally scheduled in statute.
38.	EPA, "Regulation of Fuels and Fuel Additives: Changes to Renewable Fuel Standard Program; Final Rule," 75 Federal Register, March 26, 2010.
39.	For more information, see CRS Report R44045, The Renewable Fuel Standard (RFS): Waiver Authority and Modification of Volumes, by [author name scrubbed].
40.	American Petroleum Institute v. EPA, 706 F.3d 474 (D.C. Cir. 2013). More information about this legal challenge is provided in CRS Report R41106, The Renewable Fuel Standard (RFS): Cellulosic Biofuels, by [author name scrubbed].
41.	Americans for Clean Energy v. EPA, No. 16-1005, 2017 U.S. App. LEXIS 13692, at *4-5 (D.C. Cir. July 28, 2017).
42.	Under the Clean Air Act, each year's standards are required to be announced by November 30 of the previous year.
43.	EPA's late announcement of the annual requirements may be due to the depth of the analysis (e.g., difficulty in obtaining reliable and timely information from the industry) or to other factors.
44.	Written statement by Nebraska Governor Pete Ricketts, Chairman, Governors' Biofuels Coalition, U.S. Environment Protection Agency, Public Hearing, Proposed Renewable Fuel Standard Program: Standards for 2018 and Biomass-Based Diesel Volume for 2019, Washington, DC, August 1, 2017.
45.	EPA, Renewable Fuel Standard Program—Standards for 2018 and Biomass-Based Volume for 2019: Response to Comments, EPA-420-R-17-007, December 2017.
46.	42 U.S.C. §7545(o)(7)(F).
47.	For more information on the reset provision, see CRS Report R44045, The Renewable Fuel Standard (RFS): Waiver Authority and Modification of Volumes, by [author name scrubbed].
48.	EPA asserts that comments about the "reset rule" are beyond the scope of the 2018 rulemaking. EPA, Renewable Fuel Standard Program—Standards for 2018 and Biomass-Based Volume for 2019: Response to Comments, EPA-420-R-17-007, December 2017.
49.	For example, there were questions by some about the eligibility of algae-based biofuels for the RFS. For more information, see CRS Report R42122, Algae's Potential as a Transportation Biofuel, by [author name scrubbed].
50.	Approved RFS fuels and feedstocks are provided by EPA at http://www.epa.gov/otaq/fuels/renewablefuels/new-pathways/approved-pathways.htm.
51.	In July 2014, EPA approved new cellulosic and advanced biofuel pathways to include the production of compressed natural gas, liquefied natural gas, and electricity from biogas from landfills, municipal waste-water treatment facility digesters, agricultural digesters, and separated municipal solid waste digesters. Another category of a compliant fuel for the RFS is home heating oil—fuel oils which are produced from qualifying renewable biomass and used to generate heat to warm buildings or other facilities where people live, work, recreate, or conduct other activities. EPA, "Regulation of Fuels and Fuel Additives: RFS Pathways II, and Technical Amendments to the RFS Standards and E15 Misfueling Mitigation Requirements; Final Rule," 79 Federal Register 138, July 18, 2014. EPA, "Regulation of Fuels and Fuel Additives: Modifications to Renewable Fuel Standard Program,"78 Federal Register, October 22, 2013.
52.	Biotechnology Innovation Organization, "2018 RFS Volumes Set Back Growth in Cellulosic Biofuels," press release, November 30, 2017, https://www.bio.org/press-release/2018-rfs-volumes-set-back-growth-cellulosic-biofuels; "BIO Encourages EPA to Speed Approvals of New Biofuel Pathways," Business Wire, March 31, 2014, https://www.businesswire.com/news/home/20140331006205/en/BIO-Encourages-EPA-Speed-Approvals-New-Biofuel.
53.	EPA, 2017 Renewable Fuel Standard Data.
54.	For more information, see CRS Report R41106, The Renewable Fuel Standard (RFS): Cellulosic Biofuels, by [author name scrubbed].
55.	For more information, see CRS Report R40445, Intermediate-Level Blends of Ethanol in Gasoline, and the Ethanol "Blend Wall", by [author name scrubbed].
56.	The U.S. Energy Information Administration (EIA) reports that approximately 142.6 billion gallons of motor gasoline was consumed in the United States in 2017 and approximately 14.4 billion gallons of fuel ethanol was blended into motor gasoline in 2017. This equates to ethanol constituting approximately 10.1% of motor gasoline in the United States in 2017. EIA, Short-Term Energy Outlook, Table 4a, January 2018.
57.	EPA, "Renewable Fuel Standard Program: Standards for 2018 and Biomass-Based Diesel Volume for 2019; Proposed Rule," 82 Federal Register, July 21, 2017.
58.	Farmdoc Daily, Expanding the Ethanol Blend Wall—A Role for E85?, January 31, 2013.
59.	Currently, E15 cannot be sold during summer months due to Reid Vapor Pressure requirements. S. 517 and H.R. 1311 would give ethanol-gasoline fuel blends such as E15 a waiver from these requirements. For more information, see CRS Insight IN10703, Reid Vapor Pressure Requirements for Ethanol, by [author name scrubbed].
60.	There are both government and industry infrastructure initiatives aimed at increasing the availability of E15 and other higher ethanol-gasoline blends (e.g., USDA Biofuel Infrastructure Partnership and the Prime the Pump fund).
61.	EIA estimated there would be approximately 19.6 million flexible-fuel vehicles (FFVs) in use in 2016 that would be designed to use any mix of gasoline and/or E85. However, most of these FFVs are not using E85. U.S. Congress, House Committee on Energy and Commerce, Subcommittee on Energy and Power, Statement of Howard Gruenspecht Deputy Administrator Energy Information Administration U.S. Department of Energy, 114th Cong., 2nd sess., June 22, 2016.
62.	The U.S. Department of Energy reports there were 3,280 E85 fueling stations in early July 2018. U.S. Department of Energy, Ethanol Fueling Station Locations, July 18, 2018.
63.	For more information, see CRS In Focus IF10377, USDA Initiative Is Funding New Ethanol Infrastructure, by [author name scrubbed].
64.	For more information, see CRS Report R41282, Agriculture-Based Biofuels: Overview and Emerging Issues, by [author name scrubbed].
65.	For more information, see CRS Report R44854, 21st Century U.S. Energy Sources: A Primer, coordinated by [author name scrubbed].
66.	U.S. Government Accountability Office, Renewable Fuel Standard: Program Unlikely to Meet Production or Greenhouse Gas Reduction Targets, GAO-17-264T, December 1, 2016; U.S. Government Accountability Office, Renewable Fuel Standard: Low Expected Production Volumes Make It Unlikely That Advanced Biofuels Can Meet Increasing Targets, GAO-17-108, November 28, 2016.