Energy storage problems

Abstract

W I D E S P R E A D use of solar energy or wind power, except for irrigation, depends on finding practical ways of storing the energy or products. Research on the product ion and storage of solar energy is new t)eeause there has not been suflMent incentive. Countries best able to under take research and development in these fields have had an ample supply of combust ion fuels and have had little need for new sources of energy. The field of solar-energy storage is so new in impor tance tha t discussions of economic applications at present must be based on limited experimental and engineering data. They will have to be aimed at geographical areas where there is not now an adequate supply of fuel and conventional electric power. In considering the economics of solar and wind energy product ion and storage, it is impor tan t to realize that. the conditions of the highly industrialized countries do not apply and tha t capital investment and foreign exchange are difficult to obtain and tha t labor m a y be relatively abundant . I t is impor tant to emphasize also tha t we cannot th ink in terms of producing eleetricity for less than one cent per k i lowat thour as is done in the large, efficient electrical power plants of the highly industrialized nations. I t is not reasonable to compare the cost of e lec t rMty produced in solar units of one kilowatt with tha t produced in 100,000-kilowatt units of the conventional type. Stored electricity from tile sun or wind can be produced in small units of the order of kilowatts, and without large capital investment . Moreover, there is a considerable saving in the cost of transmission lines and distr ibution to m a n y small users. The cost of stored electrical or mechanical energy can be considerably greater than the cost of the energy produced directly, because of the inefficiency and the cost of the storage, and later release of the stored energy. The total cost 1' of one ki lowat thour of eleelrieal energy delivered from storage can })e expressed in the following terms :