In message , Peter Parry
writes
On Sun, 19 Nov 2006 20:19:27 +0000, John Beardmore
wrote:
In message , Peter Parry
writes

A great pity the accreditation didn't involve actual testing of
devices to prove they worked and that their performance was at least
close to the sellers invariably vastly overstated claims.

Too bad you don't know what on earth you are talking about then. That's
precisely what the accreditation of equipment does cover !!

Neither of the toy windmills have had any performance testing or
validation of performance claims whatsoever. Their "accreditation"
is a carry over from Clearskies which didn't require any performance
testing of windmills whatsoever.

As I said - for wind, I criticised it, it was fairly weak.


That of solar panels is, to put it mildly, rudimentary.

I don't think so. Have you actually seen any test results, or is this
just rank speculation on your part ?


What testing
do installers get?

Well - proof of experience by case study or mentored installations,
inspection of installations while provisionally accredited, random
inspection of installations thereafter. There are also codes of
practice, insurance requirements etc, which is plenty of bureaucracy to
be going on with thanks.


and offered a report about it if anybody is interested,

Yes please.

You have mail, though as I said in it, please do not redistribute
without the consent of CREST. (Happy to ask them if you want to use it
for anything in particular.)


As far as I recall the Windsave machine quotes a rated power at a given
wind speed - and there is nothing wrong that per se,

Depends if it is accurate as their earlier claims, some of which
comfortably exceeded the theoretical maximum a perfect turbine could
produce.

Well - I've no reason apart from your cynicism to assume that it won't
deliver 1kW at 12 m/s.


though a proper power curve would be nice.

Yes it would, I wouldn't hold your breath waiting for it though.

I don't plan to.


The real problem is that the quoted wind speed is 12 m/s, and there is a
cube law between wind speed and the energy that can be extracted. This
is something the public - and indeed many of the sales people at B&Q
level may not appreciate.

I think the senior sales people appreciate it very clearly

Really ? I doubt most of know a cube law from a short plank ?


and
produce copy for their juniors appropriately. That's why they are so
enthusiastic about using the wildly optimistic NOABL database (when
used for urban wind) with no correction for surface roughness.

Just how enthusiastic are they ? You seem very quick to criticise, but
judging by your questions, you are keen to 'score points', and not
enormously well informed about some of the targets you choose.

Don't get me wrong - I don't think horizontal axis wind turbine urban
wind is a good idea, and I fear that there may be a backlash against
renewables as a whole if it is marketed cynically. None the less I
don't know the details of who is making what claims about urban turbines
- we just warn people off them in our consultancy work, decline to
install them, and discourage others from doing so.


Cheers, J/.
--
John Beardmore