Development and testing of stand-alone small-size solar photovaltaic hydrogen power system

Informations projet

N° de convention de subvention: JOU20428

Projet clôturé

Date de début 1 Juillet 1994

Date de fin 30 Juin 1997

Financé au titre de

• Specific research and technological development programme (EEC) in the field of non-nuclear energy, 1990-1994

Coût total € 0,00

Contribution de l’UE Aucune donnée

Coordonné par

Ente per le Nuove Tecnologie l'Energia e l'Ambiente (ENEA)
Italy

Résultats exploitables

Development and testing of stand-alone small-size solar photovoltaic hydrogen power system

Environmental issues have been dictating the need of utilizing non-fossil fuel sources as hydrogen. Use of hydrogen produced by direct or indirect solar energy could solve energy and environmental problems in the future. Production of hydrogen by water electrolysis powered by intermittent renewable sources like photovoltaic, its storage and regeneration of electricity by fuel cell, is a recent technology proposed to overcome the storage limitation of renewable energy sources. A promising application of this kind of plants concerns small-size stand-alone Photovoltaic Power System located in remote areas. In this perspective the goal of this Project is to develop a Stand-Alone small-size Photovoltaic-HYdrogen power System (SAPHYS) at ENEA Casaccia Research Centre near Rome (Italy). The main objectives of the SAPHYS project were: -To assess the efficiency of hydrogen used as storage medium of solar electric energy. -To design a SAPHYS for unattended operation. A Stand-Alone small-size Photovoltaic Hydrogen energy System was designed and realized in ENEA to demonstrate technical feasibility of the use of hydrogen as solar energy storage medium. A PV array (7 kw) is connected to an advanced alkaline pressurized electrolyser(5 kW) to produce hydrogen. Gas is stored into some cylinders for long-term storage and then sent to fuel cell (3 kW) to supply energy to a simulated load when direct solar energy is not enough or available. The plant is completed with the hydrogen and the battery storage, the gas treatment section and the control system for unattended operation. An-around-the-year experimentation was performed to test the overall performance and reliability of the plant, and to validate the plant modelling and the control strategy. Plant has proven capable of operating unattended, requiring little maintenance. The only faults that stopped plant were caused by auxiliary equipment. Due to the limited testing period, data are available only for SAPHYS summer operation. Even if the use of dc-dc converter simplifies the plant design and operation, it introduces further inefficiencies and complexity. Efficiency and long-term reliability improvements can be obtained by proper design and by reducing the number of plant components. The study confirms that photovoltaic-hydrogen systems are technically feasible and are capable of operating unattended for long enough periods with limited maintenance. Overall performance are intrinsically low for the reduced efficiency of hydrogen storage cycle. Further inefficiencies depend on the parasitic energy consumption of auxiliary. At the present the adoption of a straightforward configuration as well as the increase of plant size may render more competitive such a type of energy storage in remote applications. In spite of its technical feasibility, with no major breakthroughs to be found, hydrogen from renewable energy sources is presently uncompetitive. Applications in small-scale remote power systems may represent a first market niche.