1. General principles of cogeneration

1.1 Cogeneration principle

Combined Heat and Power (CHP) is the use of a single primary energy source to generate electricity and heat simultaneously (figure 1 ). In most cases, the primary energy source is either a fossil fuel (mainly natural gas), or biogas from biomass via a production unit.

The heat produced by cogeneration can be used in a variety of ways: hot water (i.e. for heating or domestic hot water), steam and hot air (for commercial and industrial uses).

It is also possible to convert all or part of the heat into cold using a thermo-frigorific machine. This is trigeneration: simultaneous production...