The idea of space solar power proposed by Glaser was explained as a set of a solar power power station in geostationary earth orbit to transmit microwave power and a ground station to receive the microwave power. Most of the ideas and concepts since Glaser used the same context. On the other hand, Collins et al. (Proceedings SPS ＇91, pp. 132-141, 1991) introduced the concept of microwave ＇＇fuel＇＇ to assess the commercial relations of power from space, in which space solar power stations are considered to sell microwave power to any unspecified rectenna. This concept changed the theoretical context of ＇＇power from space＇＇ to an industrial and economic relation of producers and buyers of an industrial product. This new context has been applied to the SPS 2000 conceptual study. As a result, if 2.45 GHz microwave power transmission is used, each rectenna can be planned and engineered independently from the space sector by local users, especially in developing countries, who are familiar with such activities as introducing solar energy systems.