Cogeneration, also called Combined Heat and Power (CHP), is the simultaneous generation of both electricity and useful heat in a single process. The core components of a CHP plant comprise a primary mover, such as a reciprocating engine or a steam turbine, driving an electrical generator, paired with a connected system to recover the heat that is produced as a by-product of this process.
By capturing the waste heat, CHP significantly increases fuel efficiency by drastically reducing the losses inherent in electricity production. CHP is available in a wide range of sizes for many different applications using a variety of fuels. The recovered heat is typically used as part of industrial processes, hot water, space heating, or cooling.
A conventional power plant typically loses up to two thirds of its input energy in heat losses from the plant and transmission losses from the grid. CHP makes full use of the available energy by recovering the heat and avoiding long distance transmission.
CHP is a widely proven technology and is recognised across the world as a highly efficient alternative to conventional power and heat generation. Cogeneration receives strong support from the U.K. government and many Member States of the European Union, who view the technology as the solution to meeting increasingly strict carbon reduction targets and growing electricity demand. CHP is one of the most effective and practical methods of reducing carbon emissions outside of usage limitations.
CHP plants are typically sized to make full use of the available heat output, and since heat cannot be transmitted over long distances without significant energy losses, CHP plants are sited at the point of use. In contrast to conventional centralised power plants, CHP therefore eliminate electrical transmission losses through the grid, further increasing fuel efficiency.
Micro-cogeneration, or micro combined heat and power (m-CHP), is the application of CHP to the scale of commercial and residential buildings with unit electrical outputs up to 50 kWe. A typical m-CHP system features a small natural gas automotive engine which is directly coupled to a generator to produce electricity. Heat is recovered from the process by a series of heat exchangers for the engine coolant and exhaust gases, and is then piped into an appropriately sized buffer vessel where it can be used as a heat source to serve a building's hot water, space heating, or cooling systems.
Ideal applications for m-CHP
- Sports and Leisure Centres
- Swimming Pools
- Nursing and Care Homes
- District Heating Schemes
- Student Accommodation