From Wired: My Big Biofuels Bet
Which is why this Mead, Nebraska, farm is so exciting to me: The ethanol made here is not only clean but also cheap – this is perhaps the first ethanol plant to achieve both. More important, it is an early demonstration of the great potential of biohols – liquid fuels derived from biomass for internal combustion engines. The facility is the first data point in what I call the biohol trajectory. (See “March of the Biohols,” page 143.) Like Moore’s law, this trajectory tracks a steady increase in performance, affordability, and, importantly, yield per acre of farmland. A number of biohols appear along this performance curve, among them corn ethanol, cellulosic ethanol, higher-energy-content butanol, and other biomass-derived fuels that are even more energy-rich than butanol. We’ll see fuels with higher energy density and better environmental characteristics, and we’ll develop engines better optimized for biohols. Ethanol and the newer fuels will yield better fuel efficiency as innovations like higher compression-ratio engines make their way into vehicles. In addition, we can count on the emergence of complementary technologies like cheaper hybrid vehicles, better batteries, plug-in hybrids, and more efficient, lighter-weight cars.
But the single most critical variable in the biohol trajectory is the coming rise in the number of gallons of fuel produced per acre. As we migrate from biomass derived from corn to biomass from so-called energy crops like switchgrass and miscanthus, I estimate that biomass yield will reach 20 to 24 tons per acre, a fourfold increase. At the same time, new technologies will enable us to extract more biohols from every ton of biomass, potentially to 110 gallons per ton. The result: We’ll be extracting 2,000 to 2,700 gallons of fuel per acre (as opposed to about 400 gallons with today’s technology). With better fuels and more-efficient engines improving mileage by about 50 percent, we can safely predict a seven- to tenfold gain in miles driven per acre of land over the next 25 years. Given this biohol trajectory, a future of independence from gasoline becomes not only possible but probable. And the trajectory begins with garden-variety corn ethanol.