Energy Facts

Combined Cooling,
Heat and Power

 

Combined Cooling Heat and Power (CCHP) systems are widely used in countries like Denmark, and generate both heat and electricity.

The system works by making use of the heat that is usually lost as waste – for example as steam seen rising from traditional coal-fired power station cooling towers – during the process of producing electricity.

With a CCHP system, the electricity is generated and the system then recovers the heat that is normally lost during this process of electricity generation. The recovered heat is then used to provide hot water, which is then used to heat and cool homes and public buildings linked to the local CCHP network.

In its simplest form, a CCHP system uses a turbine to produce steam. This steam then turns the generator that produces the electricity used on the site. The waste heat and steam is recovered through a heat recovery boiler. This produces the hot water that is fed to the site for use in the central heating and cooling systems.

CCHP is effective because the plants are small-scale and sited close to the community that they are serving. This means that there is minimal loss of power and heat when delivering the energy to the homes, or to public buildings.

Homes linked into the community-wide CCHP system enjoy reduced energy bills as CCHP is very efficient. Also, individual homes no longer need to have their own boilers to provide central heating and hot water, so maintenance and service costs are lower.

A CCHP system typically burns fuel such as organic materials, known as biomass. This fuel is also often called 'bioenergy' or 'biofuel'. CCHP does not burn fossil fuels such as coal.

Though the main fuel so far for use in CCHP schemes has been natural gas, fuels that can be used include renewables such as municipal and industrial waste, sewage gases, biogases, biodiesel, and wood from fast-growing renewable crops.

Using biomass as a fuel has environmental and economic advantages.

The use of biomass promotes recycling and waste management by harnessing energy from products often disposed of at landfill sites. It is most cost-effective when a local fuel source is used, as this promotes local investment and employment.