
A few weeks ago Prof. Chris Somerville and Vinod Khosla gave separate talks at Stanford on future energy sources; I’ll begin with Somerville’s talk on ethanol production. He motivated the subject with Nate Lewis’s estimate of how much land would be necessary to satisfy the country’s energy needs with ethanol. Biodiesel wasn’t covered, although he alluded to the fact that you can make it in your bathtub! He stated that while current corn grain ethanol plants are so profitable that they can raise $12 million in funding within a day, the future is in cellulosic ethanol. His best bet is miscanthus (switchgrass perennial - seen on the right, courtesy U Illinois) which grows on the east coast (as it depends on decent rainfall). You can’t simply burn the biomass as it’s not efficient (you can’t get it into small enough particles like you can with coal - 100 microns), so you have to boil it with acid, neutralize it, separate the sugars, ferment, and treat with enzymes to finally get 12% ethanol which is sold for about $3 a gallon today (see historical prices here - ethanol began trading on the Chicago Board of Trade in 2005). Went into detail about the inability of enzymes to break down biomass if it has more than 25% lignin, as well as efforts to sequence relevant plant genomes with the Joint Genome Institute.
On to Khosla. His VC firm hasn’t published their investments, but he went through some of them in his talk - in addition to the list here there is nanoh2o. One of the companies, LS9, was cofounded by Chris Somerville. Another, Amyris Biotechnology, has an interesting story. Founded to originally develop synthetic artimisinin for cheap malaria drugs with the help of the Gates Foundation, Khosla approached him to see if the same techniques could be applied to biofuels.
Further points from the speech:
- ethanol yields have been gowing up in Brasil for 25 years without advanced technologies
- biodiesel & corn ethanol won’t scale in terms of gallons per acre
- a report from the IPCC detailed how you can potentially have negative carbon emissions for driving your car, as plants sequester carbon while they grow
- imagines solar being used for electricity and biofuels for cars
- is betting on solar (concentrated) thermal such as power towers, not photovoltaics themselves. believes will be able to eliminate coal (though his estimates rely on the cost of carbon)
- thinks a cellulosic ethanol breakthrough is easier than a battery breakthrough as lithium batteries have a theoretical max that is 2-3x of today’s capacity
- imagines an entire industry of bio-refineries instead oil refineries, producing platform chemicals like succinic and lactic acid
- the time from financing to manufacture of a solar thermal plant is 10 months, compared to > 5 years for a nuclear plant
- coal power plants emit more uranium/thorium into air than from all nuclear accidents
- railed against the American Petroleum Institute’s claims that ethanol can’t be transported in existing pipelines - claimed is possible (they do it in Brazil), as long as it’s not mixed with oil
- the subsidy on ethanol went from the growers to the oil companies thanks to the ADM
Finally, he opined that people need to treat global warming as a tractable problem, instead of focusing on the symptoms. I’m guessing this is in reference to Branson’s carbon sequestration challenge. Just as in medicine, there are prophylactic treatments to prevent the problem, and palliative treatments to alleviate the symptoms. The best metaphor for carbon sequestration as a solution to global warming I can think of is that of my friend who used to smoke his way through a pack of cigarettes, and then scramble for his asthma inhaler when overcome with a coughing fit. Repeat ad infinitum until you drop dead or need a refill cartridge, whichever comes first.
While there seem to be a few E85 (85% ethanol, 15% gasoline) cars on the road, there’s not a single station offering it within 100 miles of me. Though I was shocked when I saw this notice on a Shell pump in a nearby station about ethanol mixed in with the gas.