The mini domestic power station replaces the pilot light in an everyday boiler and can generate heat and electricity at a fraction of the cost of normal power. 

The super-green device will also more than double energy savings, its British developer, Ceres Power, claims. 

The generator can do all this mainly by using cheaper materials at more efficient temperatures. 

Instead of components put together with expensive platinum, the cells are made largely from stainless steel and ceramics, using fairly standard low-cost manufacturing techniques. 

Fuel and air create a chemical reaction at an optimum temperature of 550C, generating enough electricity in the average home to make power stations obsolete, the company claims. 

"It is like the shift from mainframe computers to PCs, " said Peter Bance, Ceres Power chief executive. 

"Electricity is no longer the realm of the big." Conversion of domestic boilers is said to be straight-forward, and cost about GBP2,500 the same as a conventional premium boiler. 

Although natural gas and oil can be used to power the cells, other fuels, including hydrogen, can be used, producing water rather than carbon dioxide as a by-product.