Combined Heat and Power (CHP), also known as cogeneration, is a mini-power station that simultaneously generates both electricity and useful heat and can be run on a variety of fossil or renewable fuels.
Conventional large scale power plants emit heat as a by-product of generating electricity and simply vent the heat into the atmosphere through cooling towers or flue gases. The advantage of CHP is that it captures the heat and makes use of it for homes and offices or for industrial purposes. Heat customers can either be next to the plant, as is typically the case in industrial applications or heat can be distributed in the form of hot water or steam through pipes in a District Heating Network.
If an absorption chiller is added to the plant, the energy can be used for cooling, providing cold water down to 5DegC, which is suitable for air conditioning or industrial chilling applications; tri-generation.
By capturing the excess heat, CHP uses heat that would otherwise be wasted, potentially reaching an efficiency of up to 95%, compared with 35-50% for the best conventional plants. This means that less fuel is needed, dramatically reducing costs and CO2 emissions. Firing CHP with locally grown biomass adds to the environmental advantage and makes it one of the most efficient ways to produce energy.