PV power module
As this is a stand alone set up the electrical loads have been minimised and 12VDC has been chosen for its safety and simplicity. The digester has a low power stirring motor with gears to produce a very slow but consistent motion to break any scum layer and stop stratification. The other important loads are the hot water boiler that needs electricity for control circuitry and automatic ignition and a circulation pump to maintain digester temperature. There will be an inspection lamp, some data logging and occasionally a computer.
Picture. Inside the PV module; battery and charge controller.
