Stove turns heat into sound and sound into power

This is achieved using a technology that is currently being production engineered with the help of a Malaysian loudspeaker manufacturer. The £2million project called Score - Stove for Cooking, Refrigeration and Electricity - is being led by the University of Nottingham, which is responsible for the linear alternator that turns the sound into electricity. Another research team at City University in London has been working on the actual stove design and the thermo acoustic engine. 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 the heat from the biomass burning stove while the other rejects a slightly smaller amount into a hot water store or for some other use. Click the link at the bottom for a diagram of how the concept works. The project has reached the point where a propane fuelled demonstrator recently produced 5.3W to charge a 24V battery. The picture (above right) shows the technology lighting up a bulb. The team at Nottingham is currently working with Daiichi, one of the largest loudspeaker manufacturers in Malaysia, in order to reduce production costs. Although the Score unit is in no way like a loudspeaker, it is compatible with Daiichi's manufacturing process. Other sources of noise that might possibly be usefully converted directly into electricity include jet engine exhaust and car exhausts. The Score device has a target cost of just £20 per household, based on the production of 1million units. It is expected to weigh no more than 20kg.