An analysis is developed for the soiar chimney, aimed particularly at deriving overall efficiency and significant performance data. Numerical values are consistent with available information on the 200 m solar chimney at Manzanares, Spain, and projected designs. Overall efficiency is directly related to the height of the chimney and is shown to be about 1% for a height of 1000 m. It is concluded that the solar chimney is essentially a power generator of large scale.