cellulosic ethanol: the fuel of the future?

Last night at Atlanta Beyond Oil I heard a presentation on the possible future of cellulosic ethanol in Georgia. Ethanol has become a byword in the transportation industry the past few years, but the opinions on it are shockingly mixed. To hear the industry gurus talk, you'd think that ethanol is a quick, easy switch for gasoline that will support our existing infrastructure with hardly a blip of transition--like a magician switching a rabbit for a handkerchief under his hat. Among environmentalists, while biofuels are touted on one hand, corn ethanol has been adamantly resisted, for numerous reasons I've blogged about before. But the irresistable conclusion is that if corn ethanol is bad, some other type of ethanol is the answer. Enter cellulosic ethanol.

The only real complaint I'd heard before about cellulosic ethanol is that it doesn't exist yet. Which isn't entirely true--there are pilot plants in Sweden, for instance, and the process seems to be theoretically feasible. But it's a long, hard process from research and development to commercial viability--usually, for new technology, a process of fifteen to twenty years. And for a technology that's still in the R & D stage, it can be very difficult to get accurate information about feasibility--not only because no one really knows yet, but also because engineers always try to give the most optimistic numbers (sometimes wildly unrealistic ones) to potential investors.

However, last night I was lucky enough to hear a presentation by an engineer who is currently working toward developing a pilot plant for cellulosic ethanol from Georgia pine trees, and so I finally got some solid information on the challenges involved. So here's my take on some of the biggest problems with the dream fuel of the future.

1. Our presenter said there are currently 24 million acres of forest in Georgia. I don't know how much of that "forest" is actually monoculture tree farms of endless pine trees, which is a far cry from the complex biodiversity of a natural forest. But leaving that aside for a minute, he went on to calculate that we could "sustainably"use 19 million dry tons per year for energy and still meet our lumber and paper needs. As far as I could tell, his definition of sustainable was simply having the same amount of acreage with trees on it at the end of the year as we had at the beginning. So we clear cut one acre of ten-year-old trees, and we plant another acre of new trees. But this doesn't allow for other plants to grow; it doesn't allow the trees to replenish the soil in a natural way. And the reality is that any time you're growing a monoculture crop without replenishing the soil, you're going to end up with a desert. In that sense, monoculture tree farms aren't really that different from monoculture corn fields. They just take a little longer for the destruction to be visible.

When one of the folks in the audience brought up this problem, the presenter said there was talk about utilizing the land between trees as well. I got a little more excited at this point, expecting him to say they would plant cover crops or companion crops or something that would help nourish the soil and make the system more sustainable. But no: they're talking about planting switchgrass between pine trees, so they can use that for ethanol as well and increase their yield per acre. Switchgrass! As though the land existed for no other purpose than to produce fuel for our cars.

Something about this just doesn't fit with my idea of stewardship. But on to the other problems.

2. Even with an ethanol tree crop that would, I'm pretty sure, turn much of Georgia into a desert, their estimate is that Georgia could produce a total of around 70 million gallons of ethanol per year. That's 22% of Georgia's current transportation fuel needs. Not to be confused with whatever the need will be in thirty or forty years, by the time all these plants could possibly be up and running. It's hardly a drop in the bucket. Would it help? Maybe. Is it worth it? That's the real question. More about that in my next point.

3. The cost estimates are that they could make a profit selling ethanol at $2/gallon, which is a very cheap price. However, a significant piece of manufacturing cost is the cost of transporting the wood chips to the plant, and for that they plan to use trucks powered by petroleum diesel. The current cost estimate is based on diesel costing around $3.20/gallon. In twenty years. Nice pipe dream, Mr. Cellulosic Ethanol, but if diesel is still that cheap in five years, I'll eat my hat.

Of course, theoretically, they could always sell the ethanol for more as the price of petroleum fuel increased, so that problem isn't necessarily prohibitive.

4. At one point in his presentation, our speaker claimed that the Net Energy Ratio was greater than 10. I found that hard to believe, but by dint of much questioning I was able to figure out that he was talking about the ratio of nonrenewable energy invested as compared to the renewable energy gained. The actual EROEI, he said eventually, is probably more in the range of 1.7. Which is better than corn ethanol. But is it enough to make it worth all this trouble? Quite frankly, I think not.

I did find it particularly interesting that he was so focused on the ratio of non-renewable to renewable energy, to the exclusion of the actual total energy required to make this process happen. I have a feeling this has to do with the success of the climate change movement in making fossil fuels a hard sell in today's market. But it sidesteps the real issue, which is how much effort it really takes to keep our cars running. At some point, we're going to have to wake up and realize that the effort isn't worth the return.

On the bright side (literally), our presenter did say that he believes solar is the ultimate answer for our energy needs, and biomass is only a short-term solution. I definitely have to agree. Is it a solution that's worth pursuing at all, even in the short-term? Well, maybe. I thought my friend Douglas has the best answer: Yes, we should pursue ethanol. But instead of trying to make as much as we possibly can, let's figure out how little we can possibly manage with. Let's set up a public transit system that can run on electricity and ethanol, and let's make it as efficient and convenient as possible. Then let's recycle all our cars and let the rest of the forests grow in peace.