Hydrogen could solve storage problems of renewable energy sources
Environmental issues have promoted the use of alternative energy sources. Storage of the energy produced by renewable energy sources (RES) has always been their limitation, resorting to solutions such as battery storage for small systems to grid feeding for large ones. On the other hand, alternative fuels, such as hydrogen, are environment friendly and their exploitation with fuel-cell technology is a promising solution for future clean power production. A combination of the above is the production of hydrogen by water electrolysis powered by a typical intermittent RES like photovoltaic panels, storing the hydrogen fuel to be used by the fuel-cell as needed. Such a system has been designed by the ENEA Casaccia Research Centre, in order to assess the efficiency of hydrogen as a storage medium of solar electric energy, coupled with unattended operation. The system is build around a 7kW PV array connected to an advanced alkaline pressurized electrolyser for hydrogen production. Produced hydrogen is stored in cylinders and fuels a 3kW fuel cell, which supplies electrical energy to a simulated load. Batteries are used for storing excess electrical energy and a control system manages the operation of the complete power plant. The plant has proven capable of operating unattended, requiring little maintenance, confirming that photovoltaic-hydrogen systems are technically feasible. Despite its feasibility, present costs are not competitive. The increase of plant size may render such a system competitive for remote energy storing applications.
