May 10 2007

Powered by sound — revolutionary stove could help reduce poverty

It’s a cooker, a fridge and a generator in one — and it could have a huge impact on the lives of people in the world’s poorest communities.

The £2m SCORE (Stove for Cooking, Refrigeration and Electricity) project brings together experts from across the world to develop a wood-powered generator capable of both cooking and cooling food. By developing an affordable, versatile domestic appliance SCORE aims to address the energy needs of rural communities in Africa and Asia, where access to power is extremely limited.

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. Mostly used in enclosed spaces, smoke from the fires can cause health problems.

The researchers are using thermoacoustic technology to convert biomass fuels, such as wood, into energy to power the appliance.

Thermoacoustic principles involve the use of sound waves. The wood is burned to produce heat. This then goes into a specially shaped pipe which produces areas of high and low gas pressure in such a way as to generate sound (in similar way to a singing kettle).

The sound energy is then converted into electricity by a linear alternator (a sort of giant microphone which absorbs the sound). The electricity is then used to power the device.

The concept behind the device is revolutionary. This is the first time that thermoacoustic technology has been used to heat as well as cool in one device using biomass fuel.

The design of the proposed device is based on proven thermoacoustic engines and refrigerators developed for applications such as combustion-fired natural gas liquefaction and radioisotope-fuelled electric power generation.  Los Alamos Laboratories, in collaboration with several industrial partners, has played a lead role in the development of thermoacoustic technology.

Using thermoacoustic technology is a more efficient way of using wood as a fuel than using an open fire to cook. It produces less pollutants. The device will also have only one moving part making it more reliable.

This moving part, the linear alternator, (really a loudspeaker in reverse) is being developed in conjunction with GP Acoustics, that make KEF and Celestion loudspeaker equipment.

Mark Dodd, Head of Group Research at GP Acoustics, said: “We at GP Acoustics and our manufacturing partner Dai-ichi in the Philippines are delighted that technology originally created for the leisure market is being used to help improve the lives of people in developing countries.”

The University of Nottingham, University of Manchester, Imperial College London and Queen Mary, University of London are partners in the project — from researching engine design to the manufacture and distribution of the stove in the developing world. Led by The University of Nottingham, the project will work with governments, universities and civil organisation across Africa and Asia, many of whom have already offered support. This collaboration will ensure the device is affordable, socially acceptable and that there is scope for communities to develop businesses to manufacture and repair locally.

Researchers from Los Alamos Laboratories are also supporting the project, along with Practical Action, a charity which promotes the development of sustainable technology to tackle poverty in developing countries. The SCORE consortium is funded by grants from the Engineering and Physical Sciences Research Council as part of its initiative on energy and international development.

Professor Maksud Helali, Head of the Department of Mechanical Engineering at the Bangladesh University of Engineering and Technology has offered his support. “Bangladesh’s energy infrastructure is relatively small and inefficient, even to low income standards, and its access to energy is difficult,” he said.

“An efficient, expanding energy system is essential for accelerated economic growth and poverty alleviation. Industry and commerce depend on readily available, reliable, reasonably-priced energy to operate and expand. It will improve the quality of people’s lives.”

SCORE Project Director Paul Howard Riley added: “Designed specifically for use by the rural poor in the developing world, SCORE is a unique design that generates electricity and can cool as well as cook. Manufactured on site, it will give many business opportunities that should increase uptake by tenfold compared with current stove designs thus significantly improving health, education and wealth.”