Cogeneration or combined heat and power (CHP) is the use of a heat engine or power station to generate electricity and useful heat at the same time.

CHP generates electricity whilst also capturing usable heat that is produced in this process. This contrasts with conventional ways of generating electricity where vast amounts of heat is simply wasted. In today’s coal and gas fired power stations, up to two thirds of the overall energy consumed is lost in this way, often seen as a cloud of steam rising from cooling towers.

• CHP typically has an efficiency of over 80%
• operators typically saving around 20% on energy bills
• operators can save up to 30% on carbon emissions
• transmission and distribution losses are reduced
• increases fuel supply security

• Electricity and heat demand must be simultaneous. This is often a problem in the summer months are the need for heating is reduced, whilst the electricity demand remains fairly constant.
• High maintenance cost
• High capital cost