Cellulosic ethanol's highly subsidized failure

Actual U.S. production of cellulosic ethanol and other cellulosic liquids compared to the targets for cellulosic biofuels specified in the Renewable Fuel Standard

Cellulosic ethanol, once a great green hope for cutting petroleum use and CO2 emissions, has been a bust. The chart above compares the volume of cellulose-based liquid biofuels (largely ethanol) actually used in the United States to the targets for such fuels set by Congress when it expanded the Renewable Fuel Standard (RFS) in 2007. Note the logarithmic scale on the vertical axis; the gap between promise and reality is so large that actual production would be barely visible on a linear scale. 

The fuel has been delivered at levels of no more than about 0.1% of (three orders of magnitude less than) the volumes on which the RFS was premised [1]. This chart does not include cellulosic biogas, which EPA re-classified to qualify for RFS compliance purposes and has seen recent production of around 500 million ethanol-equivalent gallons. However, such "renewable natural gas" is not in the spirit of the law, which envisioned liquid biofuels that could be readily used in motor vehicles. The 2019 RFS target for cellulosic biofuels was 8.5 billion gallons, set to reach 16 billion gallons by 2022. But in 2019, before the pandemic-related drop-off in 2020 for nearly all forms of energy, only 9.8 million gallons of cellulosic ethanol were tallied by EPA.  

Carbon balance effects of biofuel expansion

The 4th biennial America's Grasslands Conference organized by the National Wildlife Federation was held in Fort Worth, Texas, on 14-16 November 2017. What follows is the narrative with key slides from my presentation in the session on "The Ethanol Mandate as a Driver of Land Conversion and Carbon Emissions." 

I imagine that you have often heard that ethanol and other biofuels are "clean and green" compared to ordinary gasoline. Even if not perfect, aren't biofuels better than petroleum because they recycle carbon from the atmosphere instead of getting it from under the ground? That makes them inherently carbon neutral, many people believe.

Unfortunately, that belief is quite misleading. Take, for instance, the claim that corn ethanol reduces greenhouse gas emissions by 43% compared to gasoline, as given by a recent USDA study (which is critiqued here). That value is based on computer modeling and the assumption that biofuels fully recycle carbon is hard-coded into the model. However, when using field data to evaluate how much CO2 is actually recycled, it turns out that such modeling is off base, and not by just a small amount. In fact, biofuels fall so far short of being truly carbon neutral that they cause higher rather than lower CO2 emissions than petroleum fuels.

Biofuel Research vs. Mandates: House Science Committee Hearing

John DeCicco speaking before the U.S. House of Representatives Committee on Science, Space and Technology, where the Subcommittees on the Environment and on Energy held a joint hearing entitled "Examining Advancements in Biofuels: Balancing Federal Research and Market Innovation" on Tuesday, July 25, 2017. What follows is the statement delivered at the hearing. 

I wish to thank the chairs, ranking members and other members of the Committee and Subcommittees for the opportunity to testify.

The question being addressed today, that of the right balance between fundamental scientific research and government intervention in the marketplace, is crucially important. The focus on biofuels is telling because it involves so many aspects of the question. Indeed, federal biofuels policy provides a morality tale of how things go wrong when the right balance is not maintained.

Before delving into the problems, however, I want to emphasize the importance of maintaining a robust federal investment in research across all fields of study. Funding for science is crucial to maintain American leadership and foster the innovation that leads to high-quality job growth. Federal support for university research is especially crucial for training a new generation of Americans who can fill those jobs. 

Carbon balance effects of real-world biofuel use

Most of the debate about the environmental merits of biofuel use has been based on lifecycle analysis (LCA). Also known as life-cycle assessment, carbon footprint analysis, "cradle-to-grave" analysis, or (in the case of motor fuels) "well-to-wheels" analysis, LCA is a method for adding up all of the impacts of interest associated with a product. It includes the effects of producing a product and its component materials, associated shipping and packaging effects (as relevant), the use of the product and any related disposal effects. For assessing climatic impacts, LCA tallies the greenhouse gas (GHG) emissions associated with the production, use and disposal of the product. When the product is a motor fuel, the numerical result of such LCA modeling is called the fuel's "carbon intensity," as calculated for California's Low-Carbon Fuel Standard (LCFS), for example.

A cornfield does not absorb CO2 from the atmosphere
any more quickly when it is used to make ethanol than
when it is grown for food or feed. This basic fact of 
carbon mass balance is ignored by the lifecycle studies
that claim climate benefits for biofuels. 

The question, "how does the overall emissions impact of using a biofuel such as ethanol compare to that of a fossil fuel such as gasoline?" seems straightforward, and sounds like something that LCA can answer. However, that question is actually ill-posed scientifically speaking. In other words, when one looks carefully at what actually happens when a given biofuel substitutes for a fossil fuel, it turns out that LCA cannot give a straightforward, unambiguous answer. Properly qualified, the answer will always be, "it depends." And it doesn't just depend on the particular fuel and how it is produced; it also depends on the design of the LCA model and the assumptions it invokes.

Latest tweak to U.S. biofuel mandate is politically correct and ecologically cruel

EPA's new Renewable Fuel Standard (RFS) proposal modestly increases the amount of biofuel that America's cars and trucks have to consume next year but still keeps the total renewable fuel mandate below the Congressionally scripted target.

In the plan released on May 18, ordinary corn ethanol gets a 300 million gallon boost, biodiesel is bumped up by 100 million gallons and other so-called advanced biofuels see a 200 million gallon increase compared to last year's regulation. Nevertheless, the proposed 18.8 billion gallon total remains significantly lower than the 24 billion gallon goal for renewable fuel in 2017 that Congress wrote into law back in 2007.

EPA's approach reflects a compromise worked out last year after several tortuous years of regulatory delay. This "politically correct" strategy has the agency taking a middle road that balances the money-making interests of the biofuel industry and the corn and soybean lobbies against the engineering and economic realities that render ethanol and biodiesel such inferior motor fuels. Reactions to the proposal were predictable. The renewable fuel lobby and its allies complain "that's not enough" while the oil industry and other critics say "that's too much" biofuel.

House Oversight Testimony on the RFS

This post is a transcript of my oral testimony at the U.S. House of Representatives as delivered on March 16, 2016. 

I wish to thank the Chairs, Ranking Members and other members of the committee and subcommittees for inviting me to today’s hearing.

My name is John DeCicco and I am a research professor at the University of Michigan Energy Institute. My main focus is transportation fuel use and its environmental impact. I hold a doctorate in engineering from Princeton University and have worked on America's energy challenges for nearly 40 years, including 21 years at environmental organizations before returning to academia in 2009.

My recent research has included scientifically rigorous evaluations of the Renewable Fuel Standard (RFS) and other policies that promote biofuels such as ethanol and biodiesel. RFS proponents claim that the policy reduces CO2 emissions. I have found that it does not. In fact, from its inception, the RFS has increased rather than decreased the amount of CO2 entering the atmosphere compared to petroleum fuels such as gasoline.

Questions and responses on RFS testimony

House Science Committee Hearing on the RFS, November 3, 2015
(photo credit: Michael A. Waring) 

Following the recent hearing on the Renewable Fuel Standard (RFS) held by the House Science Committee, the subcommittee chairs asked me to respond to some questions for the record, following up on my testimony at the hearing. Here are the questions and an abbreviated version of the answers, summarizing my full written response. 

In his testimony, Mr. Coleman referenced cellulosic ethanol that is "129 times better than gasoline on carbon emissions." Based on your research, is this a reasonable claim?

No, that is not a reasonable claim. Such assertions are based on paper studies of hypothetical ethanol production methods. There is indeed a literature on the subject that applies lifecycle analysis (LCA) to proposed cellulosic ethanol production methods and projects that the resulting systems would not only fully offset tailpipe CO₂ emissions but also offset other CO₂ emissions such as those from fossil-based electricity generation.

However, as pointed out in my testimony (and in papers explained elsewhere on this blog), the LCA methods used to justify such claims are scientifically incorrect. Moreover, the cellulosic processing methods involved remain speculative as far as any meaningful commercial-scale operation is concerned. In short, claims of biofuels that achieve a more than 100% reduction in carbon emissions are rooted in flawed analysis of fantasy fuels. 

Testimony on the RFS

Here's my statement at today's House hearing on the RFS; see links at the end to access the written testimony and related videos. 

My research shows that the Renewable Fuel Standard, or RFS, has been harmful to the environment from its inception. Now, ten years after the 2005 Energy Policy Act, the program has resulted in higher CO2 emissions than would have occurred otherwise. It also harms the environment in other ways. Sadly, the adverse impacts of the RFS have grown worse since it was expanded by Energy Independence and Security Act (EISA) of 2007.

The notion that renewable fuels readily reduce CO2 is based on a scientifically incorrect understanding of carbon neutrality. Only under certain conditions does substituting a biofuel for a fossil fuel neutralize the CO2 leaving the tailpipe. For that to occur, harvesting the feedstock must significantly increase how rapidly cropland absorbs CO2 from the atmosphere on a net basis. That condition is not met for the corn ethanol mandated by the RFS. It might be satisfied for cellulosic feedstocks, but once properly evaluated, the gains may not be as great as advocates assume.

The mistaken modeling behind biofuel boosters' emissions claims

Arguments about the pros and cons of biofuels such as ethanol have gone on for many years. The latest debates pertain to whether proposals to limit the ramp-up of the Renewable Fuel Standard (RFS) would result in higher or lower emissions of carbon dioxide (CO2) and other climate-disrupting greenhouse gases.

This week Environmental Protective Agency (EPA ) Administrator Gina McCarthy tweeted the benefits of biofuels: 

and signaled the agency's intent to further raise the RFS volumetric mandate: 

At the crux of the issue is the ability to determine the “carbon footprint” of biofuels using computer models. These models, such as the GREET model developed by Argonne National Laboratory in Illinois, use what are known as lifecycle assessment techniques that claim to account for all of the emissions associated with producing and using a fuel. GREET modeling is the basis for assertions by BIO (the Biotechnology Industry Organization) that the RFS has reduced carbon emissions since it was passed in 2005. It is also the basis for the recent University of Illinois statement that the proposed RFS limits would increase CO2 emissions as much as putting nearly one million more cars on the road. 

An unheeded warning on ethanol

As concerns about the adverse impacts of expanding biofuel use continue to mount, I can't help but note that a number of policy analysts raised red flags about the issue a decade ago, when proposals to mandate biofuel use began to get legs in Washington. Such was the case for a short position statement opposing an ethanol mandate that I co-wrote while on staff at the Environmental Defense Fund (EDF).

The 9/11 attacks in 2001 shocked U.S. public sentiment in many ways, including a re-awakened concern about energy security and the risks of dependence on foreign oil, as many put it. Policymakers suddenly became much more willing to seriously back petroleum alternatives. Biofuels had long enjoyed a basic level of support, including subsidies established following the 1970's oil crises. Ethanol advocates now saw an opportunity to boost biofuel production in a political climate that made policymakers from both parties happy to intervene in the market as a way to show the public that they were taking action on energy security.

Bills to mandate ethanol in gasoline were introduced early in 2002. The policy immediately found support, especially in the Senate where heartland votes easily overcame the skepticism of members from the left and right coasts.

A number of environmental organizations viewed biofuels as a crucial renewable alternative to petroleum-based gasoline. Although the net benefits of corn ethanol were always questioned, some green campaigners thought it had at least modest benefits. Just as importantly, they believed that mandating ethanol would build a market that would eventually shift away from corn to hoped-for cellulosic feedstocks that were considered much more beneficial.

Along with fellow EDF staffer Tim Searchinger, I was then quite skeptical of ethanol. The position statement we wrote opposing the ethanol mandate argued that its greenhouse gas reduction benefits were small at best while the expansion of corn growing that it would induce would be harmful to wildlife and water quality.

Needless to say, cautious voices like ours were drowned out by the rising chorus of those who were promoting biofuels for one reason or another, from the understandable self-interest of corn growers and processors to energy security hawks and green advocates of renewable energy.

Although other policy disagreements prevented an energy bill from passing in 2002, the ethanol mandate was one of the most widely supported provisions. It was re-introduced in successive Congresses, passing as part of the 2005 Energy Policy Act and then being greatly expanded by the 2007 Energy Independence and Security Act (EISA).

In retrospect, our reasons for skepticism were even better founded than we knew at the time, and the ethanol mandate has turned out to be even more of an environmental disaster than we imagined.