The fundamental investigations into atmospherothermic solai chimney power plants and the construction of the pilot plant were commissioned by the Minister of Research and Technology of the Federal Republic of Germany. The work was supervised by the energy research project management department of Kernforschungsanlage Jiilich GmbH (The Jiilich Nuclear Energy Research Establishment). The basic principles of solar chimney power plants are presented in the form of simple estimates. From the relationships between the physical principles on the one hand and the scale and construction costs on the other, it may be concluded that economical power generation will be possible with large-scale plants designed for up to 400 MW/pk. A number of the design features of the pilot plant in Manzanares are also described.