Design considerations for Mars photovoltaic systems

Considerations for operation of a photovoltaic power system on Mars are discussed with reference to Viking Lander data. The average solar insolation on Mars is 590 W/m², which is reduced yet further by atmospheric dust. Of major concern are dust storms, which have been observed to occur on local as well as on global scales, and their effect on solar array output. While atmospheric opacity may rise to values ranging from three to nine, depending on storm severity, there is still an appreciable large diffuse illumination, even at high opacities so that photovoltaic operation is still possible. If the power system is to continue to generate power even on high-optical-opacity (i.e. dusty atmosphere) days, it is important that the photovoltaic system be designed to collect diffuse irradiance as well as direct. Energy storage will be required for operation during the night. Temperature and wind provide additional considerations for array design