Cooking with sound - SCORE stove enters test stage

Components of a bio-mass powered generator which could greatly enhance the availability of electricity for rural communities in Africa and Asia are undergoing initial testing at Queen Mary, University of London.

The £2m SCORE (Stove for Cooking, Refrigeration and Electricity) device works by converting heat energy into sound and then into electricity, providing an affordable, versatile domestic appliance that can be used in the world’s poorest communities.

The initiative is funded by the Engineering and Physical Sciences Research Council (EPSRC) and brings together experts from across the world, including Queen Mary, Nottingham University, Manchester University, City University London, the charity Practical Action, and Los Alamos National Laboratory.

Researchers in the School of Engineering and Materials Science at Queen Mary are working on the heat transfer aspects of the device. In the basic design, two heat exchangers produce a temperature gradient in a porous material in which some of the thermal energy is converted into sound. One heat exchanger takes heat from a wood-burning stove: the other rejects a slightly smaller amount to a hot-water store, or makes use of it in some other way. The sound is then turned into electricity by a ‘linear alternator’.

Professor Chris Lawn commented: “There are many ways in which conventional technology makes this possible. However, the emphasis here is on doing it in a design which is potentially cheap and robust, with virtually no need for maintenance. Moreover, heat transfer to the oscillating flows associated with sound waves is not well-characterised, so we are building a rig with some prototype components to confirm our calculations.”

Dr Cat Gardner, who is responsible for building the rig, added: “A significant challenge is generating the high intensity sound, to acoustically excite the complete device, which will occur naturally in the finished product. With help from Pioneer, a drive system consisting of two mega sub-woofers has been devised that will give us the acoustic power required to fully test the heat exchanger performance”

The SCORE team is now looking for sponsorship to fund testing in the countries in which the generator will eventually be deployed.

Practical Action, a charity which promotes the development of sustainable technology to tackle poverty in developing countries are already leading field trials of the cooking component in Nepal and Kenya and will expand the test site when more units are made available.

It’s thought that complete units will be available for testing in field trials next year, with full production of the SCORE generator taking place after 2012.