Fuel cells convert hydrogen gas into electricity. The potential for using fuel cells in our cars and our buildings is great. But the hydrogen for fuel cells must be produced from some other energy source. Staff from the National Renewable Energy Lab explained that for fuel cells to be clean energy, the process to produce the hydrogen has to be nonpolluting. If fossil fuels such as natural gas are used to generate the hydrogen, the results are presently close to the same as burning the fuel. Producers of electricity from renewable energies want to use fuel cells to store and transport the energy produced from the wind and the sun. A lot of research on fuel cells is occurring now.