Although energy prices are at their lowest level ever in real
terms, there is no doubt that many families have difficulty in affording a warm
comfortable home. At the same time, the UK is faced with significant challenges
in meeting the environmental commitments agreed at Kyoto. Energy taxes are
proposed to focus attention on energy efficiency measures, but, as history has
shown, they are extremely unpopular. So is there a solution which both provides
cheaper energy and lower environmental impacts?
CHP (Combined Heat & Power) has been identified as the
most significant single measure in reducing our pollutant emissions and is a
highly efficient method of meeting the energy needs of industry and
householders. Traditionally we have generated electricity in a power station and
thrown away the heat in cooling towers. We then pay again for heat in the gas
boilers in our homes. CHP on the other hand, takes the waste heat and pipes it
to the homes of people living nearby. This makes better use of the fuel and thus
provides lower fuel bills to the householders.
However, there are limits to how far the heat can effectively
be transported and this kind of CHP, known as Community Heating, is only
economical in high density housing areas. For individual blocks of flats a
packaged CHP unit may be installed, but economic considerations make this
difficult for smaller schemes. So how can we obtain the benefits of CHP for the
homes which do not fall into either of these categories?
Micro-CHP is effectively a power station in your kitchen.
Instead of using a gas boiler, the waste heat from the micro CHP unit is used to
heat the home. At the same time it provides effectively free electricity, some
to your home and the excess to your neighbours.
The micro CHP unit is based on the Stirling engine invented
as long ago as 1815. Natural gas is burned to provide the motive power in the
engine which drives an electrical generator. The waste heat from the engine, in
the form of hot water, is pumped through the radiators of a conventional central
heating system. The micro CHP unit runs just as a gas boiler would, heating the
home whenever you need. But there are times when you need electricity, but no
heat, like in summer. Then you need to buy some electricity from the grid as
before, but you also sell your excess to the grid reducing the overall
electricity bill dramatically. In practice it is most likely that Energy Service
Companies will be set up to handle all this for you, so all you will notice is
lower fuel bills.
But before investing in new technology, you should consider
every practical means of reducing energy consumption, by loft insulation, cavity
wall insulation, double glazing, draught sealing and so on. However, there are
many homes where such measures are simply not feasible and it is for those that
micro CHP is ideally suited.
In order to encourage the uptake of CHP in housing, the
Energy Saving Trust have set up the Residential CHP programme which provides
advice through a network of expert consultants, as well as funding for
feasibility studies and capital costs.