On 12/07/2012 19:00, John Rumm wrote:
On 12/07/2012 17:10, harry wrote:
On Jul 12, 2:00 pm, GB wrote:
General priciples discussed a while back here
https://groups.google.com/forum/?hl=...csearchin/uk.d...
People are looking at this the wrong way around. It's an electricity
generator first and foremost. The Carnot Cycle means that rather more
than half the energy used will be waste heat that is just dumped at the
power station or used to heat the nearest greenhouses. With this
mini-CHP, that waste heat will be used to heat your home. That's the
theory, anyway.
Nice that somebody can understand what's going on.
There are a lot of very uneducated people round here and it shows in
their replies..
Harry, go have a look at the specs of some of these things so that you
understand what;s going on... Many are heating boilers first and
foremost, producing at most 1kW of electrical power from a stirling
engine of some form.
The one that started this thread claims "The target performance for the
Kingston appliance is to have an overall efficiency equivalent to a
high-efficiency condensing boiler and an electrical efficiency of 10%."
http://greentech.co.uk/energetix-lau...r-uk-homes-341
Converting gas into electricity at an efficiency of 10% does not sound
that impressive. It is unclear whether their claim of "overall
efficiency equivalent to a high-efficiency condensing boiler" includes
the lekky as well. If not the you might argue its worth having since its
"free", but as with most free lunches, you can end up spending money
that its hard to recoup on the plate and cutlery.
I think they must mean that you convert 10% of the gas input into
electricity, as well as having the same heat output as from a standard
boiler.
I agree with you that the practice is probably far from perfect, but you
can't really argue with the theory, especially given the ridiculously
generous FIT of 11p/KWh.
I haven't been able to find out how much these appliances cost - I
expect a fortune.
BTW, what happens if there's a power cut? You can't go on supplying the
grid, or you'll electrocute the poor technician at the local substation
trying to fix the problem.
Or should that be
?