Here's a project with real vision: UK researchers are trying to build a three-in-one cooker, generator and refrigerator that runs on biomass fuel, like wood. And they're going to use some interesting technology. The clip below shows a mockup of what it may look like - the five-year project has just started.
(Video: Paul Riley/University of Nottingham)
The heat from the fuel will be used to create sound using specially shaped piping - like a whistle. The sound will be converted into electricity by a microphone-like device to supply the fridge and power sockets. The sound will be at 50 Hertz to produce alternating current like that from the mains. Fifty Hz sounds like a low-hum to human ears - but the pipe should contain most of the noise.
Imagine the impact the SCORE project (Stove for COoking, Refrigeration and Electricity) could have in a poor community in the developing world. Having a source of electric power for light and the ability to refrigerate food would improve quality of life immensely, and reduce the risk of food-borne disease.
Perhaps the perfect complement to the SCORE device would be some kind of simple biofuel fermenter/distiller for communities to make some cleaner fuel. Although as we've reported before, they can also cause health problems.
"The sound will be converted into electricity by a microphone-like device to supply the fridge and power sockets. The sound will be at 50 Hertz to produce alternating current like that from the mains."
The sound level needed to deafen a human contains surprisingly little energy. So to carry so much power this sound must be... well, loud.
The principle of operations for this type of engine can be explained on my blog. www.jontwiford.com
I posted a video from a Spanish professor, but a post or two back links to an article that explains it lay-mans terms.
The engines can most certainly be used with solar power. They can work with any heat source. If the temperature differences and cylinder are made properly than there is no need for any moving parts other than the piston (or speaker!)