Abstract: This invention consists of a system and apparatus for converting solar heat to electrical energy by accumulating normally non-heated air under a transparent roof which covers a vast area of sand, gravel, or rock covered ground. The accumulated air is sucked into a very high tower of large diameter which is centrally located on said roof, by the existing air pressure differential. A central pedestal located within the tower, at its base, supports an electrical generator which is powered by an impeller which is activated by the air rising in the tower. A pair of truncated cones joined at their truncated openings provide a reduced area within which the impeller is located in order to increase the air velocity at this point, and the air entering the impeller is previously caused to assure a rotary motion by angular air entrances in an enclosure around said pedestal.