Combined Heat and Power (CHP)

Combined Heat and Power (CHP)

Combined heat and power (CHP), also known as cogeneration, provides thermal energy for buildings or processes while simultaneously generating part of the electricity needed at the site. It is the sequential production of two forms of useful energy from a single fuel source.


A CHP system recovers heat from electricity generation for productive uses such as heating, cooling, dehumidification, and other processes. This heat is usually wasted at conventional power plants. Because the electricity is generated near the point of use, it is subject to fewer transmission losses than electricity supplied by distant central power plants. For these reasons, properly designed CHP systems can be more than twice as efficient as the average U.S. fossil fuel power plant. Growing numbers of Federal facilities are turning to CHP technologies to gain greater control, reliability, supply quality, and flexibility in their power systems, as well as to cut costs and to meet Federal energy efficiency and emissions reductions goals.

The conversion of fuels to electricity produces large quantities of waste heat as a by-product, which conventional power plants simply reject to the environment. There has been an upsurge in interest in fuel-efficient distributed energy resources such as CHP among project developers, Federal facility managers, and policy makers because these systems help mitigate some key power sector constraints. For example, CHP systems decentralize power generation to locations near facilities having thermal requirements that can be met with waste heat. Also, CHP systems are potentially 70% to 85% efficient in utilizing fuels. They can also meet increased energy needs, reduce transmission congestion, increase power quality and reliability, and increase the energy security of a facility. CHP systems recover usable heat and avoid transmission and distribution losses to potentially deliver total efficiencies of 70% to 85%.

Source: United States Department of Energy

illustration of cogeneration, or combined heat and power