Does NASA’s $1.35 million prize for Pipistrel’s ultra-efficient electric airplane signal a new chapter in aviation, or is it just a sideshow? I tend to think it’s the first step down a long and bumpy road that could take general aviation in new directions.For people who fly for fun — presuming there are many of those left, it seems to be one of the fastest-shrinking segments of GA — electric airplanes are sure to appeal. They are easier to deal with, and quieter, with less vibration. A few years ago at Oshkosh one of the Yuneec executives said that when model aircraft switched over from messy little gas engines to electric motors, the hobby grew dramatically. He hoped the same would happen with real airplanes, and I think that makes sense. A nice clean battery-powered airplane just seems more modern, more reliable, simpler, cleaner, and more manageable to a new aviation prospect. A motorglider with a quiet little electric motor can take one or two hobby flyers aloft for hours, and lunch probably would cost more than the power used. An electric trike could take sport flyers on epic flying adventures, without the tiresome noise and rattle from a gas engine.For flight schools, the technology is just about perfect. Since most flights only last an hour or two, the limited lifespan of current technology is not a problem. The savings in maintenance and fuel costs are likely to be significant.But is it really any “greener”? Electric motors recharge off the power grid, which is supplied mainly by coal-burning power plants, not exactly emissions-free or squeaky clean. But since the efficiency is so high, electrics still come out ahead. Pipistrel’s winner, for example, carries up to four people and averaged out at equivalent to about 100 miles per gallon of gas. Even a Prius gets only about 50 mpg. Another advantage of battery power is that if managed properly, it doesn’t impose extra stress on the grid. Since powerplants can’t be shut down and restarted every day, there is always excess power on the grid at night. Batteries provide a way to store that energy and use it later. So lots of batteries could be powered by existing powerplants, using energy that is now just going to waste, before any excess demand would be created.All these efficiencies multiply to make battery power superior to gasoline. There are other issues, with some of the materials that are needed for batteries, for example, and how to dispose of them once they’re dead, and how long before they have to be replaced. But the technology is evolving fast, and the more we find good uses for it, the more incentive there is to improve.Is it economically feasible, over the lifetime equivalent of a gas vs. electric airplane? I don’t know if anyone has done that study in detail, but in any case the answers today might be different in a year or two, or five or ten. Add in the grim geopolitical costs of our current fuel system, the problems with leaded gas, the trillions of dollars in government subsidies, the cost of oil spills, ad infinitum, and the scales tip even farther toward investing in an electric future for flight.