So, remember how the feds have caved into the corn division of corporate agribusiness in promoting corn-based ethanol as the current preferred alternative fuel?
Remember too how several of us have expressed concern about the resource consumption and energy inefficiency involved with corn-ethanol?
Seen at Scientific American:
Once established, the [switchgrass] fields yielded from 5.2 to 11.1 metric tons of grass bales per hectare, depending on rainfall, says USDA plant scientist Ken Vogel. “It fluctuates with the timing of the precipitation,” he says. “Switchgrass needs most of its moisture in spring and midsummer. If you get fall rains, it’s not going to do that year’s crops much good.”
But yields from a grass that only needs to be planted once would deliver an average of 13.1 megajoules of energy as ethanol for every megajoule of petroleum consumed—in the form of nitrogen fertilizers or diesel for tractors—growing them. “It’s a prediction because right now there are no biorefineries built that handle cellulosic material” like that which switchgrass provides, Vogel notes. “We’re pretty confident the ethanol yield is pretty close.” This means that switchgrass ethanol delivers 540 percent of the energy used to produce it, compared with just roughly 25 percent more energy returned by corn-based ethanol according to the most optimistic studies.
Perhaps Bush wasn’t completely silly in his promotion of switchgrass in a past State of the Union address. It’s a shame, however, that the idea hasn’t caught on as preferable to the cult of corn ethanol.
