Is domestic CHP dead and buried?
Posted by Simon Fixter on 21 April 2011 at 1:56 pm
The going price of a Stirling based domestic micro-CHP (combined heat and power) unit of between £3000 - £8600¹ takes some swallowing, when you compare it to prices for the most efficient A-rated (Sedbuk) central heating boilers of around £600-£1,000, (some with 5-year service-free periods included)!
So the cost per kW of heat and power over the lifetime of these devices marketed by British Gas (Baxi Ecogen) and E.on (WhisperGen) appears much higher than at first it seems. For the Baxi system, no break-even for about 7 to 8 years, by which time, perhaps, the system will need to be replaced. So at first glance the cost of ownership looks prohibitive, despite micro-CHP electricity being generated much more efficiently.
Micro CHP could be one thread of a solution to reducing the cost of electricity production if the capital prices can be substantially reduced. They can also reduce our need for coal and nuclear generation methods on centralised electricity suppliers whose efficiency, due to technology, is poor; in fact, half as efficient in comparison to CHP, 45% and 90% is the differential quoted!
I am no economist, but would be interested to see if CHP can stand the light of day, in comparison to say, the costs of building and the ongoing running overheads of 2 nuclear power stations? Just think, if that money was routed instead to the installation of CHP's, what would their cost be then?
Who is distributing CHP domestic systems to the market on behalf of the manufacturers Baxi and WhisperGen? E-on and British Gas. The question has to be asked ... is it in their interest the let the householder generate their own power? Is it in the interests of Government to lose power tax income? It's early days to see if these distributors deliver the perceived promise of the efficiencies that CHP appears to offer.
Ecogen doesn't fill me with enthusiasm for a system I would dearly consider buying, if I could be given the information upon which to make a decision! The Shrewsbury Ecogen Case study was so banal as to be insulting. Detail quoted from 'John' the homeowner, such as 'it's a fair bit of kit' and ' I like the wall plate that the unit is attached to' beggars belief.
Where are the running cost comparisons between his specific new and old systems? Cost of servicing, noise level measurements, re-piping costs, boiler re-location, response times to heat 'n' litres of hot water etc? Perhaps I'm acting as devil's advocate, as the the spreadsheet provides some figures. I'd have liked to have seen John's bills, as after all he offered himself as a case study.
I may be doing them a disservice, but the distributors have and are not helping themselves by their poor quality responses to enquiries and sparse information they are releasing. Baxi has been trialing these units for years. Why the reticence to release meaningful information on their trial sites? Is it because the results are so good it will bring a seismic change in heating and electricity generation, or so poor the apparent benefits come at a prohibitive cost of ownership?
We can't evaluate anything until we have someone to give a practical analysis of these systems. Are these prices good or are they being front loaded to discourage uptake?
All interesting questions on which the jury is presently out, but for now with the current information levels I can't make any decision. Some people know the answers and they aren't letting on.
I note that only a limited number of units are attracting feed-in tariffs. Why is that? Who is getting these units? British Gas are failing to respond to me, so I can't delve more deeply into costs at this time. What do you think?
¹ £3000 - quoted from the British Gas price comparison spreadsheet. - an incremental (?) capital cost
£8600 - approx cost of a basic E.ON system in Germany
More information about CHP from YouGen
About the author: Simon is an electrician and plumber, and has refurbished his own home.
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