Photovoltaic Space Isle for Conversion in Hydrogen as Energy Vector: the Concept of a Stratospheric Airship for Energy Production, Telecommunications and Territorial Surveillance

A new interest of airships has begun about 15 years ago and it is witnessed by futuristic and fascinating projects. But nowadays it seems that some projects are going to become reality, despite the economic crisis. Specialized aerospace magazines presented the project JHL40 teamed by Boeing with the Canadian company SkyHook. It is a heavy-lift aircraft that combines helicop-ter rotor systems with a neutrally buoyant airship. It is considered the first heavy transport hybrid which is going to be operative. Some high altitude platforms are cur-rently in pre-design phase for civil purposes, essentially telecommunications and digital broadcasting, and military systems such as air defence and surveillance. Due to their heavy operative tasks both transport airships and high altitude platforms need large energy supply for very long enduring mission. A concrete possibility is con-stituted by photovoltaic energy production associated to a fuel cell system for hydrogen and oxygen. It is a closed mass loop cycle based on renewable solar energy, ex-cept a fractional dissipation in the hydrolytic process. It produces hydrogen and oxygen dissociation from water by electrolysis, coupled with a fuel cell system for night-time energy supply fed by O2 and H2 tanks. This paper investigates hydrogen and oxygen production by stratospheric lighter-than-air platform with large hull photovoltaic surface, at operative altitudes above 12 km, which is defined in order to avoid dangerous meteoro-logical phenomena like summer cumulonimbus and clouds shadowing in order to maximize solar energy in-tercepted in a year.