As Arnold pushes for hydrogen highways, Ron Bailey notes a National Academy of Sciences report that brings a reality check to this aspect of the alternative fuels debate: The hydrogen economy is not about to replace conventional sources of energy anytime soon. “There will likely be a lengthy transition period during which fuel cell vehicles and hydrogen are not competitive with internal combustion engine vehicles, including conventional gasoline and diesel fuel vehicles, and hybrid gasoline electric vehicles,” the report’s executive summary announces. Thus, “impacts on oil imports and CO2 emissions [from hydrogen] are likely to be minor during the next 25 years.” The report reckons that Department of Energy (DOE) milestones for fuel cell vehicles are “unrealistically aggressive.” But it does optimistically estimate that 25 percent of new vehicles sold in the U.S. might be hydrogen-powered by 2027, and further posits (that is, assumes) that full replacement of gasoline light-duty vehicles with hydrogen vehicles might take place by 2050. Before all this can happen, towering technical hurdles must be jumped, with no currently obvious solutions. After 40 years of federal and private R&D, fuel cell technology still has problems: “costs are still a factor of 10 to 20 times too expensive,” and the cells are “short of required durability, and [their] energy efficiency is still too low for light-duty-vehicle applications.” I’m as big a techno-optimist as you’re apt to find, but hydrogen doesn’t seem to have much of an immediate future as a replacement for our current energy system. Besides, why use electricity to make hydrogen to make more electricity? Why not just use electricity for what you need and instead do a lot of research on improving battery technologies?