Maximum conversion efficiency for the utilization of direct solar radiation

The maximum conversion efficiency for the utilization of direct solar energy is investigated. A fixed quantity of radiation is considered, and the essergy or potential work of the system is determined. The more significant case of a steady-flow process which is representative of realistic collection and utilization systems is also investigated. For the steady-flow process the Carnot efficiency for a reversible engine operating between fixed temperatures is obtained as the limiting value.