Combined Heat and Power Generation Suppliers and Advice – CHP

Combined heat and power, also known as CHP or co-generation, is a process of capturing and using heat produced through electricity generation. Electricity generated via power stations is not very efficient, with an energy efficiency of only around 37%. A large source of energy is simply released into the atmosphere and this is what is harnessed by CHP. CHP delivers good value energy. It can produce energy savings of up to 40%. CHP helps to reduce harmful carbon emissions by emitting up to half the quantity emitted by conventional systems.

For use in the home, a micro CHP unit, which is rather like a gas fired boiler, provides space and water heating as well as electricity to power appliances and for light. Properties using CHP will probably also be connected to a grid and have a back up boiler in order to receive a supply of energy when CHP plants are undergoing maintenance or where energy demand is high. CHP is most efficient when supplying energy to properties close by as it loses heat when transported over long distances. In addition, close proximity to a property means fewer carbon emissions helping to meet Government Carbon Reduction Targets.

Micro CHP units range from about 1-6kw capacity. These units are the size of a conventional boiler and are initially installed by a specialist. CHP systems are particularly useful in remote settings. The CHP system is usually combined with a gas fuel warm air boiler for supplemented space heating. CHP currently operates on a piston fired system and requires annual maintenance and servicing.

Initial costs are fairly high. For a system with electricity generating capacity of 1.2kw and 11,000Btuh heating capacity, a cost of twice the amount of conventional heating equipment is to be expected, at around £6,000 to £12,000. Cost for installation for the additional natural gas line and venting and electrical requirements are around £2,500 for 2-4.7 kw. Annual maintenance costs amount to approximately £350.

Installation involves fitting a new boiler, but existing ducts and heating pipes can remain unchanged. An indirect water heater provides hot water. An additional gas connection and vent pipe are required. Benefits include grants available as part of the Low Carbon Buildings Programme. CHP systems are best suited to properties of 3 or 4 bedroom size, and older properties where insulation is not possible, such as houses built with solid brick walls.

Current systems do not offer much in the way of financial savings for newer and smaller properties. Carbon savings are maximised when heating is required for prolonged lengths of time. CHP systems are beneficial and savings can be made on fuel bills when used for over 12 hours per day. Carbon savings of 5-10% can be expected at around 200-800kg per year. It is necessary to check with the local authority before installation to see whether or not planning permission is required, particularly if a grant is sought. An annual saving of around £150 per household can be expected, if some excess energy is sold on.