Combined heat and power (CHP, also known as cogeneration) is the simultaneous production of power (electricity) and heat from: natural gas (dominantly), coal, oil, biomass, biogas and waste heat (recovery), among other sources. Waste heat can be heat from waste incineration, waste heat from power production and/ or industrial/ commercial/ even residential waste heat. Fuel sources vary from project to project, country to country.
For example, in Iceland, the dominant source for CHP is geothermal. Over half the energy use in Iceland, which has the highest energy use (per capita) of any nation in the world, is geothermal, and much of it CHP. This is energy production for electricity and heated water/ steam for fish farms, pools, etc… and also for geothermal district heating and space heating in general.
CHP can be seamlessly integrated in a number of energy technologies. Often, systems are developed exclusively for onsite generation of electrical and/ or mechanical power, in addition to HVAC and water heating. CHP is most often developed with a gas turbine and a heat recovery unit or a steam boiler with a steam turbine. CHP exists in industrial and commercial buildings, institutional campuses, municipal facilities (district energy systems, wastewater treatment facilities, etc…) and is also implemented for residential properties.
CHP significantly reduces greenhouse gas emissions by 1/3 to ½ or more, and is significantly more efficient, requiring less fuel to produce a given energy output. CHP can produce electricity and thermal energy on site, avoiding the grid and avoiding energy losses that occur via standard transmission and distribution, as well as power outages. The high efficiency inherent in CHP saves consumers money on their utility bills, offering a reliable source of high-quality energy.