Ceres Power, a £150m AIM-listed company, recently demonstrated its new Combined Heat and Power product. This power plant is targeted at ordinary domestic homes. Combining an efficient central heating boiler with a fuel cell that converts gas to electricity, the new product has excited the City. Ceres is extremely optimistic about sales of the device, based on the cash and carbon dioxide savings it says can be achieved.

The Ceres fuel cell (on the left) is incorporated into an ordinary domestic condensing boiler (on the right)

Ceres promises reductions in utility bills of £300 a year and 2.5 tonnes savings in carbon dioxide for the typical UK house. Our short report shows why we think that these savings are unlikely even in the most appropriate UK installation. In fact, the emissions reductions are likely to be minimal and the reductions in the electricity bill will not easily justify the approximately £1,000 extra cost of the CHP cell.

Micro CHP is a difficult proposition. Other companies have found that it is hard to make substantial savings in domestic installations. CHP is not well suited to rapidly fluctuating and unpredictable demand for electricity and hot water.