People interested in biofuels should try to get get hold of a hard copy of this month's wired magazine, or better still, 'cos its free, should go to Wired's online archive
Vinod Khosla (he co-founded Sun Microsystems and is linked with Bio Willie) explains why he’s betting on biofuels
the article examines
a closed loop bioethanol facility in the middle of the Great Plains in Mead, Nebraska
Vindod says this is can produce more energy than it consumes:
For every BTU of energy used to run the ethanol plant, five BTUs are produced. A typical corn ethanol plant produces 1.3 to 1.8 BTUs for every BTU of fossil fuel input, including the energy required to grow the corn. (Gasoline has half the efficiency of corn ethanol, producing 0.8 BTUs for every BTU input.)
WHEN IT COMES TO TECHNOLOGY, the best way to change the world is not by revolution but by evolutionary steps. Change must follow from step to step, from innovation to innovation, as technology matures, each step justifying its economic viability and attracting investment. So while ethanol may not be ideal, I’m convinced it’s the best first step on the biohol trajectory. Ethanol offers one thing no other oil substitute can: a clear path from where we are to where we hope to be.
Kholsa says new crops are the key:
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.
Although he doesn't say if there'll be enough water for them or if they will really be sustainable in large volumes without using high quantities of inorganic fertilizers.
But you should read the rest yourself in Wired on-line.