Taken your hydrogen-powered FreedomCAR out for a spin lately? Nope? Well, there is plenty of time to sign up for one, suggests a National Research Council report that pegs 2020 for the arrival of the mass-market fuel cell vehicle.

That's the best case scenario, of course, assuming technology, government, industry and the public all cooperate on bringing hydrogen cars to the nation's highways.

"The use of hydrogen fuel cell vehicles can achieve large and sustained reductions in U.S. oil consumption and CO2 emissions, but several decades will be needed to realize these potential long-term benefits," says the NRC report.

Fuel cells combine hydrogen with a chemical catalyst to make electricity and water exhaust. In contrast, the nation's 235 million cars and light trucks burn about 44% of the country's oil and release about 20% of its industrial carbon dioxide emissions. All told, transportation represents about 5% of the U.S. contribution to global warming, but spikes in the price of gas have sharpened interest in alternatives to gasoline, such as biofuels and hydrogen.

In 2002, then-Energy Department chief Spencer Abraham unveiled the $1.2 billion FreedomCAR effort, which partnered DaimlerChrysler, Ford, General Motors and others in a research push for fuel cell cars. The CAR in FreedomCAR stands for "Cooperative Automotive Research" and the Freedom meant freedom from oil imports, greenhouse gas emissions and "Freedom for Americans to choose the kind of vehicle they want to drive, and to drive where they want, when they want," according to the Energy Department.   Read rest…