In the present study, the feasibility of P.S.I.C.H.E. (Photovoltaic Space Island for Conversion of Hydrogen as Energy vector), a stratospheric platform for hydrogen and oxygen production by photovoltaics, has been investigated theoretically for altitudes between 10 and 20 km form the ground at 45° latitude north. The upper envelope of the airship is equipped with a PV array that covers energy request during the day; surplus in power supplies an electrolyzer for hydrogen and oxygen production from water. Products are compressed and stored. With insufficient solar irradiance and during the night a fuel cell system fed by hydrogen and oxygen tanks supplies power requirements. Typically atmospheric conditions in Po plain were used for evaluation of PV performance at various altitudes. A propulsion system with electric motors grants airship manoeuvrability and hovering. Energy balance of PV-hydrogen energy supply system has been analysed for three airship shapes with equal volume with concern of overabundant hydrogen and oxygen production. Total weight and payload are calculated in relation to altitude. Storage tanks dimensions and products ground transportation frequency has been estimated. Hydrogen yearly production for PV square meter has been valued in relation to ground production at the same latitude.