Solar hydrogen energy trade

Abstract Traditionally, more than 90% (1989) of the world's requirements for primary energy have been met by coal, oil, natural gas and nuclear energy, the rest met by biomass and hydropower. Efficient energy-use is beginning to be viewed as an additional ‘energy’ and has immense potential, especially in industrialized countries. The possibilities for on-site use of solar energy from irradiance, wind, hydropower, ocean thermal energy gradients, biomass and ambient heat are far from exhausted, despite their growing share of the total. Solar hydrogen will become irreplaceable as an energy carrier because solar energy from areas with the greatest insolation or highest hydropower density has to be seasonally stored and transported worldwide, and in macroeconomically relevant amounts. Solar hydrogen is free of energy raw materials, and thus free of related pollutants. It is also a closed loop energy, compatible with the existing world energy trade system and enhancing it with a product which is inexhaustible, renewable, ecologically responsible and of low-risk.