Two boxes that look a bit like an air conditioning unit are installed under the eaves of a house in a quiet residential district on the outskirts of Nagaoka, Niigata Prefecture.

The smaller box is a fuel cell generator and the bigger one is a tank holding hot water produced by the generator. Electricity production proceeds quietly, and not a sound is heard.

The house is one of 32 sites nationwide used to test fuel cells in homes. The tests are being conducted by the New Energy Foundation with the support of the Ministry of Economy, Trade and Industry.

A family of four lives in the house but Naoki Shida of the Niigata prefectural government's industrial development division said the family does not have to pay much attention to the ongoing tests.

''All they have to do live normal lives using electricity, dipping in the bath or taking a shower,'' Shida said. 

The fuel cells operate automatically and the data are transmitted to the Industrial Institute of Niigata Prefecture in Niigata via a personal computer linked to the generator.

Fuel cells, which are an efficient clean-energy source, are considered minigenerators as they release water and heat in addition to generating electricity through a chemical reaction between hydrogen and oxygen.

One of their major benefits is that they do not emit carbon dioxide which causes global warming or release air pollutants.

The sites picked for the experiments during fiscal 2003 included ordinary households like the one in Nagaoka and stores. 

Energy-related enterprises such as electric, gas and oil companies, electric machinery makers and local municipalities took part in the tests.

From the beginning, the Niigata prefectural government has been putting efforts into a plan to promote the introduction of new regional energy sources.

''Niigata Prefecture yields natural gas that extracts hydrogen,'' Shida said. ''We suggested that we should participate in the experiments to find whether fuel cells can be used widely even in snowy areas. In due course, we'd like to lead the experiments to foster industries to produce hydrogen in cooperation with local enterprises.''

But fuel cells for home use have not yet gained much recognition, certainly not to the extent fuel cell cars that Japanese, U.S. and other automakers in the world are striving to turn out.

''To be sure, fuel cells for home use are not as visibly colorful as cars,'' said Tomio Komata, chief of the fuel cell division of the foundation's planning headquarters. ''But what we are after is energy saving, a cutback in CO2 and low running costs. By realizing the three goals, we will be able to cope with demand for energy that will increase in the future and also prevent the environment from deteriorating.''