The Hydrogen Economy

Abstract

The hydrogen economy is a vision for a future in which hydrogen replaces fossil fuels. There are a variety of methods for generating, storing and delivering hydrogen since no single method has yet proven superior. Economically, the wasteful hydrogen process translates to electricity from hydrogen and fuel cells costing at least four times as much as electricity from the grid. In fact, electricity would be much more efficiently used if it were sent directly to the appliances instead. Low density and extremely low boiling point of hydrogen increases the energy cost of compression or liquefaction and the investment costs of storage. The low energy content of solar irradiation dictates that photosynthetic processes operate at high conversion efficiencies and places severe restrictions on photobioreactor economics (Hallenbeck and Benemann, 2002). Looking forward, towards the end of the century, solar-hydrogen type of fuels could be an option for a global energy economy.