The validity of hydrogen as a fuel source has been questioned in regard to both environmental impacts and cost effectiveness. How valid do you consider that argument?
Hydrogen is an energy carrier, which can be produced from a number of renewable and non-renewable sources including wind, solar, hydro and natural gas resources. Fuel cells, in turn, produce only water and heat as by-products and no pollutants. Greenhouse gas (GHG) savings from the use of hydrogen in fuel cells depends almost entirely on how the hydrogen is produced in the first place. When renewables such as hydro and solar are used, the process is effectively emissions-free. When using fossil fuels such as natural gas, GHG emissions are considerably lower when reformed to produce hydrogen and used in fuel cells than if simply burned in combustion engines.
