* Target of 100-150 Watts electrical thermo-acoustic generator (stove, fridge, electricity) for £20 in 1 million quantities with half the wood and no smoke
* weight: 10-20kg
* 1.6 kWth for cooking and 0.75 kWth for simmering.
– Fuel: consumption 1 kg/hour, wood, dung and other bio-mass.
* fuel is placed inside the stove and burned. The fire heats compressed air that has been pumped into specially shaped pipes located inside the stove’s chimney and behind the stove. The heated air begins to vibrate and produce sound waves. Inside the pipes, the noise is 100 times louder than a jet taking off. But because the pipes are stiff and do no vibrate, the sound waves have nowhere to go. So outside the pipe, people hear only a faint hum.
* The sound waves vibrate a diaphragm located at the end of the pipe. The diaphragm is attached to a coil of metal wires that sit inside a magnet. As the wire coil vibrates — about 50 times per second — it generates an electrical current, which is captured by wires and converted to the proper voltage.
* The stove has electrical sockets, where the homeowner can plug in, for example, a mobile phone for charging. Or she can sell the electricity as a phone-charging service.
* For refrigeration, the heated, compressed air is sent through a different part of the pipe, where sound waves cause the air to expand. As it expands, it cools to a temperature that can produce ice. It takes about two hours of stove use to produce enough ice that will keep the fridge cold for 24 hours. But homeowners have the option of producing more ice to sell for income.
* 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.
The ice that is produced could be placed into the 5-6 day commercial coolers. A constant supply of ice would enable the coolers to constantly keep food cold. The thermo-acoustic generator would be very useful for camping or for survival situations.