Micro Combined Heat & Power (CHP) is defined as the
simultaneous production of useful heat and power within the home. 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 t
o
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 80% of the energy in the gas is converted into heat and the remaining 20% is lost in the flue gases. The electricity generated in the home has a value which covers the investment cost of the micro CHP unit and provides a net saving.
The micro CHP works very much like the gas central heating boiler and heats the home in just the same way. However, at the same time it generates electricity, some of which you will use, the remainder is exported to the grid to be used by your neighbours. The only difference you will notice is lower fuel bills...and a cleaner planet!
It is most likely that, at least in the early stages, you will not actually buy the micro CHP unit. Instead you will be offered a package of services by an energy supplier which may include the rental of the unit, electricity and gas supply, and a maintenance service contract.