Are anaerobic digesters a net loss for the environment?

Most people are probably only dimly aware of AD – if at all – even though many are helping to feed the plants by putting aside food waste for collection by the local council.

The leftovers of unwanted children’s meals and food past its best-before date are placed in closed digesters and left to decompose in an airless environment – the result is the production of a methane-rich biogas that can be burned to produce heat or electricity (or both) or which can be fed directly into the natural gas distribution network.