There are a couple of companies offering small scale...

There are a couple of companies offering small scale decentralised Biogas solutions now as it has become apparent that there is only room for a few large ones in Australia due to distances, cost of transport, etc. Mining camps are on their list. Entec Biopower out of Austria have designed a solution which is distributed in Australia by Concept Environmental Services. I believe they are a modular containerised plug and play system that requires much less feedstock but also delivers a lot less energy. I read somewhere 150kW per container, but as it is modular, you could put a few containers together. Not sure how much feedstock is required. Entec also build full scale plants, but I'm sure there is a reason that they have now also come up with this concept.