Another readily available source for biomass energy generation is municipal solid waste. This includes decayable and non-decayable wastes that are usually dumped into sanitary landfills. The municipal solid waste can be converted into energy by direct combustion or natural anaerobic digestion.Another source of biomass for energy generation is forestry residues. This includes residues generated during cutting of branches in plantations, clearing of roads for logging activities, cutting stem-wood for timber, wood processing into saw dust and wood chips. These residues which are usually left on the sites to rotten can be collected and used to provide energy. Industrial wastes are also a good source for biomass energy generation. These include residues and by-products from the food industry ranging from industrial meat production to confectionery production. It also includes foods like fruits, vegetables, pulps, starch, sugars, coffee that do not meet regulatory standards and consequently disposed off. Industrial wastes also include liquid waste generated during washing of meat, fruits and vegetables as well as pre-cooking of meat, poultry, fish. Liquids generated during wine making and cleaning activities are not left out. All these are industrial wastes which can be used to provide energy.
There are different pathways through which biomass can be converted to energy. One such pathway is thermochemical conversion. Thermochemical conversion can only be used to create energy when heat recovery is involved. Heat recovered from the combustion of biomass is then used to power turbines for electricity generation or for direct water heating. Another pathway for converting biomass into energy is biochemical conversion. It is used when the biomass has a high percentage of organic biodegradable matter and high moisture content. This involves composting the biomass in a controlled and oxygen-deficient condition which results in the production of a biogas that can be used to provide electricity and heat. The third pathway for generation of energy from biomass is physico-chemical conversion. This involves processes that improve the physical and chemical characteristics of the biomass into high energy fuel pellets that are friendly to the ecosystem.Waste to energy reduces green house gas emission and is therefore a very efficient means of addressing the challenge of climate change. This is because it reduces the dependence on fossil fuel energy. It provides an alternative source of energy that is better than fossil fuel in terms of damage to the environment.