Combined Heat and Power

Overview

Conventional power stations operate at efficiencies between 30% and 50%. That is, only one third to one half of the primary energy input is converted into electric power. The remainder is given off as heat. Further losses are incurred in the transmission and transformation of electricity.

Decentralised solutions for the generation of power, in the form of combined heat and power (CHP) stations, allow the heat which is given off during the generation of power to be used. In a well-designed systems, the overall efficiency will be over 80%. In other words, 80% of the primary energy input to the system can be put to good use, some as electricity, the rest as heat.

There is rarely a convenient balance between the heat and electricity requirements of a building or group of buildings. Systems will only be cost effective if there is a need for heat during the summer, for example in swimming pools or in many industrial processes. A distinction is made between two types of operation: power-driven and heat-driven. In the case of power-driven CHPs, the prime consideration is the production of electricity when it is most profitable. In the case of heat-driven CHPs, considerations of the overall efficiency are at the forefront; electricity is only generated when there the 'waste' heat can be put to good use.

In general, we advocate the heat-driven use of CHP as this optimises the efficient use of resources. We use our systems engineering expertise to design CHP installations that fulfil our clients' needs at minimum cost. This generally means that CHP systems provide the base heat load, with a second heat source topping up the heat output.

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