Is Cellulosic Ethanol Worth the Investment?

Debate Watch is a series of posts on Change.org by Brooks Lindsay, founder and editor of Debatepedia.org, an encyclopedia of pro and con arguments and quotations. Brooks has taken a particular interest in climate and energy issues throughout his career.

Cellulosic ethanol is a biofuel produced from wood, grasses, or the non-edible parts of plants. After the failure of corn-based ethanol to live up to the hype, cellulosic ethanol has picked up the mantle of progress for the biofuels sector.

The fuel has been getting more and more attention recently. A quick Google News search for "cellulosic ethanol" reveals some serious activity, including major investments, pilot projects, and government subsidies. There remain, however, big unknowns about the future of the fuel, and questions about whether companies and governments should invest.

The Pros

Environmentally, ethanol made from cellulose has significant advantages over ethanol made from corn. Because it's more efficient to produce, cellulosic ethanol yields three times the net energy. What's more, it doesn't compete with food supplies. In fact, switchgrass—one cellulose source—is basically otherwise useless and can grow on unwanted land, rather than edge out other food crops for prime agricultural real estate. As a result, cellulosic energy crops have a far lower carbon footprint and are less likely to spur deforestation for new farm land.

Cellulosic ethanol can come from a variety of plant materials. So-called "energy crops," often grasses, don't require the same intensive farming as corn demands. Switchgrass, for example, grows plentifully on its own, without the need for regular watering or fertilizing, making it a potential high-yield cash crop. In other cellulosic experiments, waste streams such as woodchips, corn cobs and even landfill trash are being recycled into the new ethanol fuel.

And, of course, cellulosic ethanol can help lower our dependence on foreign oil. It's not a comprehensive solution, but a good addition to the equation.

The Cons

Growing plants, processing them into fuels, and then burning those fuels is a tremendously inefficient way to use the sun's energy. Solar or wind power, which converts that energy directly into electricity, makes a whole lot more sense. And with electric cars down the road, gas stations may soon be a relic of the past. So, why would we want to invest in a new flex-fuel vehicles, which can run on up to 85 percent ethanol, to accommodate that outdated approach?

If we create larger market demand for cellulosic ethanol, pressure to cut down forests in order to make space for crops will only grow. If cellulosic ethanol is meant to displace a large chunk of the fossil fuel based economy, huge swaths of land would be required.

From a car owner's perspective, cellulosic ethanol is also fairly harsh on engines, degrading their efficiency. And while it is true that cellulosic ethanol is a net zero C02 emitter, it emits a huge number of particulates into the air, causing asthmatics like myself to gasp.

Finally, cellulosic ethanol start-ups are struggling. Energy author Robert Bryce said in the Energy Tribune in 2009, for example, "the hype over the fuel continues unabated. And it continues even though two of the most prominent cellulosic ethanol companies in the U.S., Aventine Renewable Energy Holdings and Verenium Corporation, are teetering on the edge of bankruptcy."

My verdict

I generally favor a any-contribution-is-a-good-contribution approach to clean energy and climate change. But to me,  this means any approach that can produce clean electricity.

Growing plants, processing them into fuel, transporting the fuel, pumping it into cars, and then burning it is certainly an inefficient process, and one that will not last through the end of the century.

So, at best, cellulosic ethanol is just a stop-gap measure while electric cars slowly replace liquid-powered cars. This is not entirely a bad thing. It could help squeeze some more value out of fuel-based cars and forestall the economic consequences of fossil fuels depleting faster than we can manage. But, a stop-gap fuel does not deserve massive investments and government attention. It deserves some, but perspective is required.

Photo credit: Wikimedia commons

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