i. What is Cogeneration?

Cogeneration is the simultaneous production of electricity and heat (or steam) both of which are consumed by one or more hosts.

How does cogeneration work?  Cogeneration, sometimes referred to as “combined heating and power,” is achieved through a heat engine or power station that uses fuel to generate electricity and captures the heat that is emitted by the electric generator.

What kinds of engines are used?  Cogeneration engines can be gas or fuel-powered.   In some smaller applications a reciprocating engine or Stirling engine – a closed cycle compression engine that is used in conventional motor or refrigeration applications – is used to generate the electricity and excess heat.  Biomass has also been used as a fuel source for combustion.  Other engines use a combination of gas and solar power.

What is trigeneration?  In addition to heat and electricity a trigeneration unit can produce cooling through an absorption refrigeration process.