On Thu, 13 Nov 2008 11:06:50 -0000, "Vortex2"
wrote:

For the past few years I've been very intrigued about these MicroCHP boilers
that are under development, for example I can see that the so-called "BAXI
Ecogen"
should be coming to market next year:

http://www.baxi.co.uk/baxiecogen

Have any uk.d-i-y ers encountered this technology yet? There must be
hundreds of these on test out there in the field.

There were, Powergen (I think) got awfully enthusiastic about them in
2004 as potential subsidy generators and imported the Whispergen
units. After some initial reports of unreliability with many being
removed it all went very quiet and although reports were that 80,000
units had been contracted for I don't think more than a few hundred
were ever installed and the production rollout date has been one year
away for the past half decade.

The Baxi unit is I presume based upon the work they did with the now
defunct British Gas subsidiary Microgen Energy Ltd.

One major problem with MicroCHP is that it only really work well in
large houses which need a lot of heating. They are very inefficient
on short run cycles. The more you insulate your house and lower the
heat requirement the less the CHP boiler generates as they only
generate electricity parasitically on top of the heating load.
Typically the carbon savings in a reasonably well insulated house will
be below 5% and in modern houses insignificant.

I'm especially interested in the noise performance. Surely these things
must produce some kind of 50/100Hz Hum!!!!!!! That would drive me nuts.

From past performance the major problem with noise appears to be the
complete absence of it as the units seem to spend a lot of time dead.
With their low life expectancy and unreliability it might be wise to
allow others to buy the first few production batches.