Energy Pros & Cons
Bioenergy comes from
burning biomass – organic matter such as wood
or plants. It supplies more than 90% of total energy
demand in Nepal and Malawi, and 25% to 50% in large
industrialising countries such as China, India and
Brazil. Austria uses bioenergy for 13% of all its energy
One of the crudest forms of bioenergy
is the open burning of dung or wood for cooking in
developing countries - though one power plant in the
UK burns chicken dung. This burning is often done indoors
- a practice responsible for about two million air
pollution-related deaths each year.
But bioenergy can also be used to convert sustainably grown crops or agricultural, industrial and municipal wastes into useful energy. Methods range from adding biomass products into coal-fired boilers, to fermenting sugar cane to produce ethanol-based car fuel, to burning methane gas produced as biomass decomposes.
Burning biomass can still release greenhouse gases, although plants grown for fuel manufacture also absorb carbon dioxide while they are growing. Depending on the fuel and process, bioenergy can be much cleaner, and the sources more renewable, than fossil fuels.