A brief review shows that domestic production of hydrogen to fuel a car is feasible by using various means. Among these, the solar-photovoltaic electricity-electrolysis process seems to be the most practical if a renewable energy source is to be used. A simplified model has been developed to determine and optimize the thermal and economical performance of domestic photovoltaic-electrolyzer systems, either with fixed or sun tracking panels using annual total solar radiation on a horizontal surface and climatic data. Twelve locations in the United Sates from four climatic zones (tropical-sub tropical, dry, temperate, cool snow-forest) have been selected. Simulations have been carried out to produce data for hydrogen production for these various locations and the resulting data have been correlated to obtain hydrogen production in kg/kW(p)/year photovoltaic system as a function of total annual solar radiation on horizontal surface. The economical feasibility has been studied by taking the photovoltaic and electrolyzer systems' price as variable parameters. It is assumed that the necessary capital is 100% borrowed from a financial institution to pay back in monthly installments. It has been found that the hydrogen production with fixed photovoltaic panels varies from 26 to 42 kg/kW(p)/year and the cost from 25 to 268 $/GJ. (C) 2004 Elsevier Ltd. All rights reserved.