"Rural communities in the developing world could soon be using a combined cooker, electricity generator and fridge powered by a system that turns heat from burning wood into sound waves." IET Engineering & Technology, June 2007
Is it April the first?
No it's not April the first
This is a weird but fascinating technological development. It's a very large and well-funded project to improve the efficiency of energy use in impoverished places, and develop a robust piece of equipment that people all round the world can use.
Crazy as it seems, using a simple open wood fire is less efficient than the proposed technique, which involves: burning wood in a special chamber that heats gas "patchily" in a specific way that produces sound, then converting that sound to electricity.