Biomass for Combined Heat and Power (CHP)
Using biomass solely for electricity generation is seen as an inefficient use of biomass. Modern commercially viable heating, cooling and cogeneration technologies can reach efficiency levels of up to 80-90%, whereas bio-power efficiencies are 25%. Only a small portion of the total energy created from burning biomass actually gets converted into electricity. Combustion of biomass produces heat, which is used to generate steam, which in turn rotates a turbine to create electricity.
When steam passes through a turbine it only loses a portion of its thermal energy. When it exits the turbine it still has a relatively high thermal energy and normally this heat is vented to the atmosphere through smoke stacks. Combined heat and power systems (CHP) focus on capturing this heat and using it for productive purposes. By attaining a higher efficiency in energy creation, CHP can result in energy cost savings, waste heat reduction and lower CO2 emissions. Processing plants that require high amounts of heat and electricity such as pulp and paper mills are ideal for this application. The key to a successful CHP plant is that there must be a demand for the heat that is captured from the electricity generating process. In Europe small scale district high plants are used with CHP technology and these plants have proven to be very efficient.
Image source: http://www.unendlich-viel-energie.de/en/electricity/details/article/111/functioning-principles-of-a-biomass-combined-heat-and-power-chp-station.html
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