That's the beauty of providing direct tax credits for consumers. The market really does determine which technology wins that way. With huge subsidies to corporations, that are obtained by industry lobbyists bribing lawmakers and regulators, tax dollars only go to the bottomline of these companies. The funds do not go to solve the problem of global climate change, terrorism due to nuclear proliferation. and the oil wars that are now threatening to turn into WW3. Right now huge subsidies in the form of liability waivers, no pollution control, wars over resources and nuclear proliferation, low (or no)cost oil leases, and scammed CAFE mileage standards to nuclear and fossil fuel industries are built into the energy choices that consumers make, added to the tax bill every year. Change these giveaways for companies that don't need them to tax credits for consumers and this energy revolt will take off. Give a higher tax break to the more effective energy and greenhouse gas saving products. So pure electric cars would get more than hybrids, plugin hybrids would be in between. It's just that simple. As far as determining which technologies are more effective at greenhouse gas reduction, reducing fossil pollution and nuclear contamination, and saving energy, that can be scientifically tested. Then used to determine the level of tax credit. Like it or not, we are almost in WW3 here due to oil and nuclear proliferation, choices based on scientific testing must be made. Have you heard how the jeep was developed for WW2? The government held a contest, the winner was manufactured. We won. This is every bit as serious a disaster as WW2. A nuclear weapon could explode in any major city anytime thanks to the funding from oil states like iran and saudi arabia and the availability of nuclear materials. Pakistan, a nation where 99% of the people side with al queda have the bomb, Saudi arabia funded that "islamic bomb", with oil dollars from all of US. The time to say, let the "free" market decide is past. it would be like FDRsaying, let the "free' market defeat the axis powers. That is obviously ridiculous. and it is obviously disastrous now. That so-called free market is a heavily subsidized, corrupt mess. And it will never head off wW3 and global climate disaster.