What is Combined Heat and Power?

Combined heat and power (CHP) (also referred to as Cogeneration) is the use of a power plant to simultaneously generate electricity and useful heat. It is among the most common forms of energy recycling.

Conventional power plants emit the heat created as a by-product of electricity generation into the environment through cooling towers, flue gas, or by other thermodynamic processes. CHP systems are designed to capture the by-product or waste heat for heating purposes. This heat is typically used at the same site or distributed to facilities close to the plant. This systems is also called Combined Heat and Power District Heating or CHPDH

In the United States, the Consolidated Edison Company of New York (CECONY) distributes 30 billion pounds of 350 °F/180 °C steam each year through its seven cogeneration plants to 1800 large customers (typically large buildings or institutions in Manhattan. It is the largest steam district in the world. The peak delivery is 10 million pounds per hour (corresponding to approx. 2.5 GW)

By-product heat at moderate temperatures (212-356°F/100-180°C) can also be used in absorption chillers for cooling. A plant producing electricity, heat and cold is sometimes called a tri-generation or more generally a poly-generation plant.

Cogeneration is a thermodynamically efficient use of fuel. In separate production of electricity some energy must be rejected as waste heat, but in cogeneration this thermal energy is put to good use.

What is Micro CHP?

Micro cogeneration is a distributed energy resource (DER). The installation is usually less than 50 kWe in a house or small business. Rather than burning fuel to heat space or water, some of the energy is converted to electricity in addition to heat. This electricity can be used within the home or business or, if the technology is available permitted by the local utility, sold back into the electric power grid.

What is Mini CHP?

Mini cogeneration is also a distributed energy resource (DER). These installations are usually more than 5 kWe and less than 500 kWe and are used in large buildings or medium sized businesses. Current Micro and Mini CHP installations use five different technologies: microturbines, internal combustion engines, stirling engines, closed cycle steam engines and fuel cells. Mini CHP has a growing role to play in the reduction of CO2 reduction in buildings.

1. energyauthority says:

   February 3, 2010 at 11:13 am

   Thanks – We sure will.