Micro CHP (Combined Heat & Power) is the simultaneous production of useful heat and power within the home.  It works very much like the gas boiler in a central heating system and heats the home in just the same way.  However, at the same time it generates electricity, some of which you will use in your own home; the remainder is exported to the grid to be used by your neighbours.

The technical and economic demands on such a system are extremely onerous and it is important to recognise that micro CHP is not simply a scaled-down version of conventional CHP. However, micro CHP offers significant opportunities to enhance the profitability of an energy company’s supply business as well as providing substantial environmental benefits.  These economic benefits may be passed on to the consumer in the form of reduced energy bills, whilst the environmental benefits are of value to all of us.

Natural gas is consumed in a Stirling engine (or other prime mover) to provide heat and electricity for use within the home. A total of around 70-80% (Gross Calorific Value) of the energy value of the gas is converted into heat, principally in the form of hot water which is used for space heating and domestic hot water as in a normal central heating system. Between 10-25% is converted into electricity, and the remainder (5-15%) is lost in the flue gases. This compares with a conventional gas central heating boiler where around 90% of the energy in the gas is converted into heat and the remaining 10% is lost in the flue gases.  Although the total "efficiency" of a micro CHP system is similar to a boiler system, the electricity produced has a much higher value than heat.  It is the value of this electricity which covers the investment cost of the micro CHP unit and provides a net saving.