For a new pressure generator of a heat engine which has been introduced in its concept recently and which works on the basis of the thermal transport of gas, calculations on the gas throttle thereby needed, the gas flow, the power density in relation to the surface, and the efficiency are carried out. Numerical data are presented for a number of cases. At 20 degrees C on the cold and 220 degrees C on the warm side of the throttle, an energy output of 205 kW/m(2) at a pressure of 1 bar on the cold side and hydrogen as working medium will be received. One, but not the only application possibility, is the utilization of solar energy with air as working medium; with this utilization without the radiation concentration a theoretic efficiency of more than 50% may be reached. A special advantage is given in the possibility of conveying the heated gas in non-heat insulated pipes and to use it also in the engine after cooling down to the ambient temperature at, however, a reduced efficiency.