Green energy

I joined a friend today on a trip to see an anaerobic digester plant near Benson. Ana who? is a 2.5MW power station run on gas - those are the turbine flues in the image. And the gas comes from, amongst other things, discarded Tesco sandwiches and household food waste. It all gets mashed up and liquified then sits in large vats for a few months while the bacteria break it down producing gas. One of the vats is behind the turbines and flues. The top is inflated with gas.
It has a faintly farm yard like smell - les than I had expected; but the smell is a bit stronger where the bin lorries drop their cargoes!
Interesting to see the production if green gas...