While green cars are generating all the buzz at the North American International Auto Show underway in Detroit, the biggest advocates of autos that use less oil are divided over the best ride of the future. Venture capitalist Vinod Khosla has posted a new analysis on the Gristmill blog to underpin his arguments that flex-fuel vehicles running on cellulosic ethanol would be more affordable, and do more for the environment, than plug-in hybrid cars with rechargeable batteries. In brief, Khosla says plug-in hybrids will cost a lot and reduce carbon emissions by 25 percent, while a flex-fuel car will cost the same as an ordinary gas engine car and reduce emissions 75 percent when run on ethanol from cellulosic material (not corn but grasses, wood chips, or other waste plant material).
Meanwhile, Joseph Romm, the former head of the Energy Department's renewable energy office, who blogs at Climate Progress, argues Khosla has undercut his credibility by dissing plug-ins, which he says will be a central strategy for dealing with climate change. Romm just blogged about his recent test-drive of a plug-in using now available battery technology. Use of existing technology is a big theme for Romm, who says we have only a short window of time to stave off climate catastrophe. Cellulosic ethanol is not here yet, although one of the companies in which Khosla has invested, Range Fuels, aims to begin commercial production later this year, and another, Coskata, just announced a big partnership with General Motors.
We recently wrote on the potentially coming power revolution, looking at Khosla and his ethanol and other clean-energy investments as well as the advocacy of Google and others on plug-in hybrids—a technology we also examined in depth.
My take: Neither cellulosic ethanol nor plug-in hybrids are here today, but both have enough great promise that they need to be pursued. Incidentally, that's just what General Motors is doing. My colleague Rick Newman wrote about its Chevy Volt initiative here and here. Also, you can check out Rick's summary of why every approach for getting beyond oil has pros and cons. We need to pursue them all anyway.