An on-farm source of alternative energy is an anaerobic digester, which can be run off of liquid manure. Anaerobic digestion produces digestate and a bioga composed of carbon dioxide and methane. Biogas can be used for energy or fuel, and have a decent energy output. Using additional material, like high energy crops, as well as liquid manure are usually necessary for proper functioning, and will also greatly increase the energy produced. Management for the anaerobic digester requires some management and skill to have it functioning properly. As well, it is useful to be connected to a grid as excess electricity can be produced. Ways to deal with payment or cost of electricity include net metering and the standard offer program (Ontario), and there are various funding programs available in Ontario.