The sources of biomass are organic matter - vegetable or animal based products from food, agriculture and waste. Biomass is collected after either being grown specifically or collected as a by product of another activity. Biomass can be converted to electricity by through different processes like combustion, gasification, anaerobic digestion, pyrolysis and fermentation.Conversion by combustion of biomass is bioenergy produced by burning biomass like bagasse is one of the oldest methods used in Australia. Bagasse is a sugar cane by product and has been used to create steam which powers the sugar mill for nearly 100 years. Combustion of wood for heat or bagasse involves burning the biomass to produce heat and steam which is then which is then used to power turbines and generators to generate electricity.
Anaerobic digestion of biomass creates biogas - usually methane or CO2 and you might be familiar with the production of these fuels from sewerage treatment plants and your local landfill site, but is also commonly made from animal manure and organic food waste. Pyrolysis is where biomass is converted to a gas by the use of heat in an oxygen-starved atmosphere. The gas produced is used to move turbines, which activates generator to produce electricity.
One of the most important points about bioenergy is that it doesn't burn fossils like coal in order to produce power. It uses alot of waste products that would otherwise be polluting landfill or some other part of the enviroment. One ongoing issue with biofuel agricultural production is the replacement of food crops with biofuel crops - starving available food production land and driving up the price of staple foods.
Small scale bioenergy processing plants are increasingly used on farms around Australia. Urban projects like Poo power are working to harness energy from the 1400 tonnes of unwanted dog poo made in Australia every day.