Another technology getting a bit of a move on is anaerobic digestion of putrescible wastes to give biogas. No, please don’t yawn and click away! If nothing else there’s a few high-scoring words for a scrabble game.
As a country, we produce around 15 million tonnes of food wastes which can be turned to good use in this way. Most still goes into landfill never to be seen again.
Anaerobic Digestion (AD) is a simple process (though it ends up with quite a complicated plant to do properly) which uses natural bugs to digest the otherwise rather unpleasant food wastes and, a bit like worm bins, results in useful output. In the case of AD we get a methane-rich gas which is then burnt in an engine to generate electricity or can be injected into our gas mains.
It doesn’t smell! Far from it. Rotting garbage smells because it has putrescible wastes within it. The AD process is contained in sealed tanks so the gas can be efficiently collected and the smell cannot escape. The one I saw is just south of Warminster and generates a fairly steady 500kW of electricity and the heat is also used in the process and to heat the buildings. The total UK potential could deliver 1% of our electricity.
Although we can reduce the amount of food waste we produce I doubt as a country we could never get it to zero, so this looks like a very good way to dispose of it.
PS: Thanks to Wiltshire Wildlife Trust for arranging the visit and Malaby for hosting.