The EPA is accepting public comment through next week on the Renewable Fuel Standard (RFS). I know, I know, acronyms are super-boring, but I promise this is important. The RFS is what sets our targets for the development and use of biofuels in our national fuel supply: stuff like that “E10” sign you see when you pull into the gas tank that says there’s been some (probably corn) ethanol added to your fuel, to investing in technologies to develop algal-based biofuel blends for commercial aircrafts.
So what are these “biofuels”, and why are they important for a clean energy future? Biofuels are not unlike conventional oil, in that they are a flammable liquid derived primarily from plants that we can put in our tanks to get around places. However, unlike conventional oil, these plants haven’t sat in the ground for hundreds of millions of years, compressing and breaking down all their complicated cell wall parts and physically and biologically homogenizing to the point at which when we pull them out of a deposit, they look nothing like plants. Because our biofuels start out as plants, we need to subject them to processes that break them down and get at their energetic contents to turn them into fuels that we can then put in our tanks; that’s what hundreds of millions of years of deposition and geographic compression has already done for us in the case of fossil fuels. What is good about biofuels lies in this difference: they are renewable (we can grow more of them, unlike conventional oil), and they often (but not always) come with a lower carbon and environmental footprint compared to conventional gas and oil.
We can think of biofuels as being in one of two main categories: fuels that can also be foods, and fuels from plants that are not generally consumed by people. In the first category goes stuff like corn, sugar, vegetable oil, and other food-related feedstocks. In the latter category are what are known as cellulosic biofuels: these are generally made from agricultural waste products, like corn stalks or beet processing byproducts, and from perennial non-food crops like switchgrass.
Food-related fuel stocks like corn had an easy jump-start in this country, because we are really, really good at growing food like corn already, and there was already a lot of it around when we started thinking about its use as a biofuel. As a result, corn-based ethanol products that we blend into our conventional fuels have skyrocketed: corn ethanol production is up around 14 billion gallons per year, and went from being 6% of of the total corn market in 2000, to 40% of the market by 2010. Although field corn used for ethanol isn’t eaten off the cob like the yummy bicolor ears you see in the grocery store, it is used as a feedstock for animals and in several corn-based products including corn oil and corn-based cereals. As a result, competition for growing corn for ethanol vs food is a real concern for driving up food prices and reducing arable land used to feed animals and people so that instead we can pour corn into our gas tanks.
The other problem is that as we’ve gotten more systemic in our thinking about life cycle analysis and the true footprint of corn-based fuels, we’ve realized that the actual carbon footprint of making ethanol is actually pretty darned big. Yes, to a large extent there’s the carbon-balance thing I talked about earlier: rather than pulling sequestered carbon out of the ground and burning it up, we’re talking here about counterbalancing some of the CO2 emitted from burning the biofuel with the carbon taken up by the next crop of growing plants. However, the growth and processing of corn for ethanol is energy intensive, so not all of that carbon is offset by plant growth; and ethanol is a lower-energy fuel than conventional oil (ethanol contains about 70% of the energy gasoline does), so you have to burn more of it to get the same mileage. The more recent life-cycle analyses put corn-based ethanol’s carbon footprint at about 80% relative to conventional gasoline. That energy discrepancy also leads to an interesting market subsidy: When the price of ethanol is between about 70% and 100% of the price of gasoline, the cost per gallon of gasoline with ethanol is lower, but it is as if the gasoline is watered down – the cost per mile driven is higher. So in effect, we drivers are at those prices subsidizing the use of ethanol in our gas tanks. And also keep in mind, its not just the carbon footprint of corn that warrants concern: corn is a chemical, water and land intensive crop, so the environmental impacts are multiple of giving over huge swaths of the US’s arable lands to corn monoculture.
So if not corn, what’s the solution? Actually, the solution quite realistically does include corn, which is certainly not going to disappear as both a heavily subsidized and well-entrenched component of the biofuels portfolio. However, many folks think that portfolio needs some diversification for the reasons Ive discussed above, and that’s where cellulosic biofuels come in. Agricultural field waste, woody biomass, perennial crops like switchgrass, and algae are among many of the nascent biofuels that are being explored and tested. In order to help these alternatives to be viable and compete against a well-established food-based biofuel market, we’re going to need both a strong venture capital interest and support for getting some of these newer technologies off and running, and a regulatory atmosphere that is supportive of biofuel diversification.
So here’s where our friend the RFS comes in to play. The Union of Concerned Scientists has some excellent articles and info on their blog that speaks to some approaches the EPA might be well-served to adopt in moving the standard forward. In much less detail and excellent analysis than they provide, I’ll try to summarize: the EPA needs to recognize that cellulosic biofuels have been slower than hoped for in ramping up to production capacity, and therefore, they need to adjust their biofuel production targets for the standard to more accurately reflect what’s really going on in the field today. However, that does not mean we should roll the standards backwards and call for target reductions; but at the same time, EPA needs to make sure that the RSF’s targets don’t outpace the actual capacity for biofuel production, and that expectations moving forward are realistic and promote low-carbon technology. We need to recognize that corn ethanol technologies are important to meet current demand, but that cellulosic and non-food-based biofuels should be included when we look to the future of a less carbon intensive, environmentally impactful biofuel portfolio.
This is hard stuff to wade through, and I think its really easy to get lost in the complex economic and technical arguments that surround biofuel development. However, the most important point to keep in mind is that supporting biofuel development, and moving towards biofuels that have a smaller carbon and overall environmental footprint, should be primary goals. And the EPA needs to hear this, because they’ve got plenty of voices coming at them from other perspectives (aka, the corn ethanol industry, and the fossil fuel industry, and those in government receptive to their concerns) when it comes to the need to move into a clean energy future. So taking just a moment to voice your support for a robust Renewable Fuel Standard is important. You can do that here in a form already populated by the Union of Concerned Scientists; or here through the Federal Register. Just a few days are left in the public comment period, so please act now!