CAN PHOTOVOLTAICS BECOME AN EFFECTIVE ENERGY OPTION

The prospects about the market volume of grid-tied PV systems appear good enough to assure the development of technology learning processes. On the other hand, the grid difficulty in accepting intermittent PV power, when this latter exceeds 10-20% of the network active power capacity, introduces an upper limit for penetration of PV systems in the bulk market of central power stations. Accounting for different capacity factors between PV and conventional power (typically 20% of PV against 55% of conventional power plants), this limit corresponds, in terms of PV annual electric energy production, to a contribution of about 3.5-7%. Since the electric energy contribution to the global energy balance in industrialized countries corresponds to about 30% of the total, the PV energy contribution will be as a maximum in the order of 1-2%. What would make the photovoltaics role marginal with reference to its contribution in satisfying the world energy demand and negligible with regard to induced environmental benefits. In order to overcome this barrier it is necessary to review PV strategy, assuming as a reference for energy competitiveness a new commercial product, made of an integrated system, PV array plus H-2 seasonal storage subsystem, and related back up generator, able to assure the load supply with continuity. The recurrent oil crises, the new environmental boundary conditions for energy production and use, and the present state and perspectives of PV and H-2 technologies lead us to conclude that the PV-H-2 system development can be a very promising strategic solution, which realizes together with the PV energy cost effectiveness goal an actual, clean, renewable, and alternative energy option.