Heat is collected in the focal point of a mirror. There are several different engines that can be used for the generation of power within the solar dynamic system. These engines are usually known by the names of their inventor. For use on Space Station, the Brayton Cycle engine has been selected. The energy storage device used for a solar dynamic power system is superior to a photovoltaic system because heat is stored rather than electricity.
Heat is cheaper and far more simple to store for subsequent use.
Storage can be accomplished by taking advantage of the heating, or fusion, of inorganic salts. On the sunny side of the Earth, heat is absorbed by the salt and it melts. An abundant supply of power is one of the top priorities for users of the Space Station and therefore, of highest priority for the Space Station Program. This concept was revised in light of budget realities. By using only photovoltaic modules in Phase I, NASA will be able to meet budget restrictions without sacrificing the needs of the users.