Photovoltaic-hydrogen energy systems for stratospheric platforms

Photovoltaic-hydrogen systems were analyzed regarding their usability as energy supply for high altitude platforms in long enduring missions. Main attention was directed to characteristics of current or near term available technology. Specific power weight of photovoltaics and other key components and their dependence on operation mode and power range were assessed. A pre-design of a PV-hydrogen energy supply system was carried out for a stratospheric airship. The calculated coverage ratio of photovoltaics and load share of energy system mark the frame of usability. Depending on the airship size, shape and other external boundary conditions the total electrical energy demand for full year operation can be covered by a PV-hydrogen energy system of current or near term technology. However further investigations are necessary regarding improvement of PV and minimization of thermal effects on lifting gas through photovoltaic generator.