ABSTRACT
This chapter reviews secondary energy systems, which are those employed when primary energy is transported and delivered for use by the consumer. An energy table for Japan would show that for electricity and gas, the original primary energy is converted into secondary energy by the energy utilities. The majority of the secondary energy that is obtained from coal is coke used in the steel industry; a very small amount of heat is derived as secondary energy. Hydrogen and methanol are likely future forms of secondary energy. In steam turbines the energy is converted once into thermal energy, so in order to use the energy efficiently, it is necessary to have a technique that directly utilizes the kinetic energy of the high-temperature gas. In order to promote greater efficiency in energy use, greater energy conservation, and greater use of unused energy, it is necessary either for energy to become more expensive, or else to introduce an energy tax.
