The NY Times has an article today announcing the successful and highly efficient production of hydrogen using a new method relying on nuclear power
http://nytimes.com/2004/11/28/politics/28hydrogen.html
Excerpt
"The new method involves running electricity through water that has a very high temperature. As the water molecule breaks up, a ceramic sieve separates the oxygen from the hydrogen. The resulting hydrogen has about half the energy value of the energy put into the process, the developers say. Such losses may be acceptable, or even desirable, because hydrogen for a nuclear reactor can be substituted for oil, which is imported and expensive, and because the basic fuel, uranium, is plentiful.
The idea is to build a reactor that would heat the cooling medium in the nuclear core, in this case helium gas, to about 1,000 degrees Celsius, or more than 1,800 degrees Fahrenheit. The existing generation of reactors, used exclusively for electric generation, use water for cooling and heat it to only about 300 degrees Celsius.
The hot gas would be used two ways. It would spin a turbine to make electricity, which could be run through the water being separated. And it would heat that water, to 800 degrees Celsius. But if electricity demand on the power grid ran extremely high, the hydrogen production could easily be shut down for a few hours, and all of the energy could be converted to electricity, designers say.
The goal is to create a reactor that could produce about 300 megawatts of electricity for the grid, enough to run about 300,000 window air-conditioners, or produce about 2.5 kilos of hydrogen per second. When burned, a kilo of hydrogen has about the same energy value as a gallon of unleaded regular gasoline. But fuel cells, which work without burning, get about twice as much work out of each unit of fuel. So if used in automotive fuel cells, the reactor might replace more than 400,000 gallons of gasoline per day."