Musical stoves

Powered by sound, a revolutionary combined stove, fridge and generator could help reduce poverty and have a huge impact on the lives of people in the world’s poorest communities. SCORE – a Stove for Cooking, Refrigeration and Electricity - first converts the heat from burning wood, coke or dried cow dung into sound waves, these are then used to power the three-in-one device.

The possibility of turning soundwaves into useful energy has been studied for centuries – you've probably observed the phenomenon yourself in old-fashioned whistling kettles – but this is the first time thermoacoustic technology has been used to convert biomass fuels into energy.

SCORE works by funneling the heat from burning wood into a specially shaped pipe which then produces areas of high and low gas pressure, this then generates sound. The sound energy is converted into electricity by a linear alternator, a sort of giant microphone, which absorbs all of the sound. The electricity can then be used to power other devices.

Using thermoacoustic technology is a more efficient way of using wood as a fuel than using an open fire to cook - it also produces fewer pollutants. SCORE Project Director Paul Riley understands that to be a success the stove must have few moving parts that can go wrong and is simple enough to be made by local craftsmen: “There would be local employment, making and supplying the stoves. We will generate businesses which can use the device to make or conserve produce as well as powering radios, charging batteries, and computers.”

The current design produces about 100 watts of power and can operate for 24 hours if needed. The SCORE project team envisages a working unit within 18 months and a million units a year to be made by 2012.

Across the world, two billion people use open fires as their primary cooking method. These fires have been found to be highly inefficient, with 93 per cent of the energy generated lost. And when used in enclosed spaces, smoke from the fires can cause health problems.

An 'improved' cooking stove was trialled in Nepal, but it was found although the the hood above the open hearth reduced smoke in the hut, the lack of choking smoke reaching the roof timbers meant that the resident termite population stayed alive.