As we look to future technologies to provide energy without generating greenhouse gases, it is clear we must stop using fossil fuels. Fossil fuels are hydrocarbon based, that is, they consist of both hydrogen and carbon. It's the carbon atoms in these fuels that create CO2 when burned.
Getting rid of fossil fuels may not be that difficult. Hydrogen fuel could replace gas and oil in many applications. Car engines can run on hydrogen, just as some cars run on propane gas today. Hydrogen gas could replace natural (methane) gas in most industrial and residential applications.
When hydrogen is burned, the gas waste product is simply water, H20! Once cheap solar power is available, it can be used to make hydrogen from water through a process called electrolysis, where water molecules are converted to O2 and H2 (hydrogen) gas. Storing solar energy in the form of hydrogen gas should be more cost-effective than using batteries or other technologies. ***