Abstract: A central solar receiving tower includes an air permeable heating surface which is exposed directly to the ambient. The heating surface receives solar radiation from a heliostat field and a warm airstream is circulated to the forward exposed face of the heating surface. As the warm airstream passes through the heating surface, its temperature is further raised and energy can be extracted from the air prior to being returned to the heating surface. The warm air introduced to the exposed face of the heating surface is directed in a generally converging pattern and flows through the heating surface with a generally uniform flow profile. A protective airstream is provided adjacent the warm air return airstream in a similar converging pattern. By properly controlling the relative flow rates, a flow boundary between the warm air and the protective air can be maintained, with the warm air flowing inward through the heating surface and the cold air flowing outward to buffer the warm air from ambient conditions.