The Fukuoka prefectural government said Tuesday it will start an experiment using fuel cells at 150 households in two housing complexes, which it claims will be the world's first example of setting up household fuel cell systems on such a scale, with 100 units in a single concentrated area. The experiment is aimed at proving the practicality of using environmentally-friendly household fuel cells for supplying electric power and heat, the prefecture said, noting that the experiment will be conducted jointly along with Nippon Oil Corp and Saibu Gas Energy Co. A single unit of the system will be able to cover about 60% of power supply needs and about 80% of hot water needs of an ordinary household, resulting in a reduction of energy consumption of roughly 30%, according to the prefecture.