Plug Power, a US joint venture, has demonstrated a fuel cell power unit that is designed to power a single home. The residential fuel cell, which has been designated Plug Power 7000, is expected to be launched commercially by 2000.

Plug Power is a joint venture between the Michigan utility DTE Energy and Mechanical Technology Inc. The development of the residential fuel cell has been supported by the US Department of Energy.

The prototype residential fuel cell runs on hydrogen, but the commercial version will burn natural gas, propane or methanol. Home systems of this type will cut residential fuel bills by around 20 per cent, the company claims.

The unit will provide power for most of the electrical units in a house including the refrigerators, air conditioning, dishwasher oven, television, VCR, microwave and lighting. In addition, heat from the unit can be re-used for water and space heating.

In a separate development, the New Jersey Department of Transportation has announced that it is to install 65 fuel-cell powered backup systems to variable message signs on New Jersey thoroughfares. The backup units will be supplied by H Power Corp under a contract worth $749 000.

The backup units will employ Proton Exchange Membrane fuel cells. The New Jersey department has said that it expects that the fuel cells will pay for themselves in three years.