For the purpose of this report only natural gas fired CHP was considered. Whilst not classified as a renewable energy technology, CHP is categorised as having a high-energy efficiency when applied optimally. It should therefore be considered as a "sustainable" technology.

The key issue with this technology is to optimise the waste heat recovery and use.

Various well proven technologies are available, the most common being reciprocating gas engines. For larger applications gas turbines can be used

Advantages

· Capability to provide the power and heat requirements for the whole development.
· Flexible and reliable
· Highly cost effective and all the heat is put to good use.

Limitations

· Balancing the heat load requirements.
· Secure supply of natural gas required.

Costs

Estimates in the range of £300 to £600 per Kwe installed.

Applications

Optimised when the heat produced is fully utilised. Therefore from a sustainability point of view, the installation size should be determined by the amount of heat required, rather than the amount of power required. In the UK this presents problems as heat is normally required for only 4 months of the year. This issue can be balanced by the application of absorption chilling for climate control.

Leisure centres, hotels and hospitals generally have the best, balanced heat and power requirements.