In article om, Dave
Liquorice writes
On Thu, 05 Oct 2006 06:13:52 +0100, Dave Fawthrop wrote:

Worse synchronising the turbine output with mains AC at the correct
frequency, phase etc, then adjusting the phase angle to feed power back
into the mains is **VERY** **VERY** difficult.

No it's not. Bung it across the mains and it will sync *very* quickly,
probably to the detriment of part of your kit though depending on how far
out you are. B-)

Commercial boxes can be bought that do everything but these small
turbines generate so little power that that expense probably isn't
justified. So you then either have a LV battery supply and distribution
or some seperate mains via an invertor to seperate mains distribution.

Also the control box needs to fail safe. It *must* disconnect your
generated power from the mains when the mains fails but if you are
feeding the mains how does it know that the mains has failed?


ISTR that one of the biggest problems was syncing with the mains. Why
feed power from small installs back into the grid why not simply use it
for heating and other purposes on your premises?..
--
Tony Sayer

On 2006-10-05 09:29:05 +0100, "Dave Liquorice" said:

On Thu, 5 Oct 2006 08:08:28 +0100, Andy Hall wrote:

Ah OK. So are you then able to do an omnidirectional coverage of a
large-ish area or is this to get the height/distance for a longer point
to point connection?

This is a point to point site with links up to 5km or so. APs are also
located at good sites and some user links are a few km long. Generally
outside of the town there is a small flat plate antenna at the AP and
short yagi at the user end.

I see. So topology is kind of like a tree with some links being
base-user--user
|
--user


?

Do you do anything to contend the bandwidth per user?

The message
from David Hansen contains these words:

"Dave Liquorice" wrote this:-

As I see it wind is not really the way to go. To get sensible outputs you
have to have huge devices(*) that on average only generate 1/3 to 1/4 of
their rated output over a year.

Are you sure you are not being over generous? Even the propagandists
don't go that far:

"One 1.8 MW wind turbine at a reasonable site would produce over 4,7
million units of electricity each year"

I make that a load factor of only 0.3.

The uninformed might believe your statement indicates that there is
something different about wind turbines. However, it is a fact that
all forms of electricity generation do not produce 100% of their
rated output over a year.

Now that is a statement worthy of a religious fanatic.

There is indeed a crucial difference between wind power and conventional
forms of generation. That is that while wind power is completely at the
mercy of the wind conventional generation can when needed produce 100%
of its rated output on demand at all times except during downtime for
maintenance or repair.

--
Roger Chapman

On 4 Oct 2006 11:15:00 -0700, dg wrote:

I noticed a wind turbine in B&Q, and it is nothing more than a motor,
on a pole with a propellor and some box of electronics.

How are these valued at over £1500 when it seems it can be made for a
fraction of that? How much would the parts be?

They are priced at £1500, not valued at £1500. Similar turbines and control
packs can be bought for £900.

On 4 Oct 2006 11:15:00 -0700, "dg" wrote:

I noticed a wind turbine in B&Q, and it is nothing more than a motor,
on a pole with a propellor and some box of electronics.

How are these valued at over £1500 when it seems it can be made for a
fraction of that? How much would the parts be?

dg

Navitron.org.uk
may be cheaper.
--
Get away from it all
http://www.travelfreebies.co.uk/thomson-holidays.htm
Late deals, mega cheap flights and bargains

In article . com,
dg wrote:
I noticed a wind turbine in B&Q, and it is nothing more than a motor,
on a pole with a propellor and some box of electronics.

Why would you want to make wind?

--
*Lottery: A tax on people who are bad at math.

Dave Plowman London SW
To e-mail, change noise into sound.

The message
from The Natural Philosopher contains these words:

I once saw this girl who had lost a remarkable amount of wight -
actually I saw her a few days ago, and she is still remarkably well
formed after over 12 years since that time..the secret..? "Eat less" she
said....

Ah, yes, the "If you don't put it in your mouth it can't go round your
waist" diet.

--
Skipweasel
Pay no attention to that man behind the curtain.

"Andy Wade" wrote in message
...
dennis@home wrote:

http://www.britishwindenergy.co.uk/you/byo.html R&D already done.

There's a link on there to Hugh Piggott's site at

http://www.scoraigwind.com/index.htm

which is quite interesting (although not a model for good Web page
design). About half-way down the page there's a section headed "rooftop
wind turbines are a load of nonsense" - interesting that, coming, as it
does, from an obvious home-brew wind power enthusiast.

Well you aren't going to get a decent flow of wind unless you put it on a
pole at least 2-3m above the roof.
You probably want 5+m.
People object to TV aerials on poles I suspect that they will treat wind
turbines the same way.

"Roger" wrote in message
k...
The message
from David Hansen contains these words:

"Dave Liquorice" wrote this:-


The uninformed might believe your statement indicates that there is
something different about wind turbines. However, it is a fact that
all forms of electricity generation do not produce 100% of their
rated output over a year.

Now that is a statement worthy of a religious fanatic.

There is indeed a crucial difference between wind power and conventional
forms of generation. That is that while wind power is completely at the
mercy of the wind conventional generation can when needed produce 100%
of its rated output on demand at all times except during downtime for
maintenance or repair.

There's another fundamental difference between wind power and conventional
(i.e. gas or coal) forms of generation.

Wind generated power is not polluting, does not use precious resources and
does not produce carbon dioxide.

It will never be able to generate all the (some imagined) need for
electrical power but it will reduce the demand for fossil fuelled
generation.

To some of us that's important - call it religious fanaticism if you like,
you won't change our minds. We care about the future.

Mary
--
Roger Chapman

On Wed, 4 Oct 2006 19:45:15 +0100, Andy Hall
wrote:

On 2006-10-04 19:15:00 +0100, "dg" said:

I noticed a wind turbine in B&Q, and it is nothing more than a motor,
on a pole with a propellor and some box of electronics.

How are these valued at over £1500 when it seems it can be made for a
fraction of that? How much would the parts be?

dg

They are not *valued* at £1500 at all. The price charged is what
they believe sufficient people will pay to justify the shelf space.
It also gives them plenty of room for manoeuvre when the inevitable
happens and they don't sell. They could probably knock 60% off the
price and still make a reasonable margin,

Also, AIUI, the price includes a survey and fitting.

With the claims they are making, the things will sell. This "30%"
business, and having it injected straight into the house mains will
camoflage the failings of the things. Only when buyers notice no
difference in their electricity bills will the con be found out, and
far too late for those who bought. In the meantime, the racket from
them will be enjoyed by neighbours.

Nobody has commented on the "solar panels", a snip at "Only £2498.00".

The message
from "Dave Plowman (News)" contains these words:

Why would you want to make wind?

It's that or bust.

--
Skipweasel
Pay no attention to that man behind the curtain.

Mary Fisher wrote:
Wind generated power is not polluting, does not use precious resources and
does not produce carbon dioxide.

The fact that more energy is probably used manufacturing them than they
will ever produce obviously isn't a consideration.

On 2006-10-05 12:02:04 +0100, EricP said:

On Wed, 4 Oct 2006 19:45:15 +0100, Andy Hall
wrote:

On 2006-10-04 19:15:00 +0100, "dg" said:

I noticed a wind turbine in B&Q, and it is nothing more than a motor,
on a pole with a propellor and some box of electronics.

How are these valued at over £1500 when it seems it can be made for a
fraction of that? How much would the parts be?

dg

They are not *valued* at £1500 at all. The price charged is what
they believe sufficient people will pay to justify the shelf space.
It also gives them plenty of room for manoeuvre when the inevitable
happens and they don't sell. They could probably knock 60% off the
price and still make a reasonable margin,

Also, AIUI, the price includes a survey and fitting.

With the claims they are making, the things will sell. This "30%"
business, and having it injected straight into the house mains will
camoflage the failings of the things. Only when buyers notice no
difference in their electricity bills will the con be found out, and
far too late for those who bought. In the meantime, the racket from
them will be enjoyed by neighbours.

It certainly will. They claim 33dBA at a wind speed of 5 m/s (11mph)
but 55dBA at 7 m/s (15mph) at 5m distance.

The latter will be highly audible. Conveniently, they don't say what
it will be at the rated speed of 12.5 m/s (28mph). 65dBA? 75?
Either way, one hell of a racket.

Hopefully customers will have a get out if neighbours complain or
planning departments intervene.


Nobody has commented on the "solar panels", a snip at "Only £2498.00".

That one's too much of a joke to even be considered.

On 2006-10-05 12:22:08 +0100, "Chris" said:


Mary Fisher wrote:
Wind generated power is not polluting, does not use precious resources and
does not produce carbon dioxide.

The fact that more energy is probably used manufacturing them than they
will ever produce obviously isn't a consideration.

Of course not. When did reality ever enter into religion?

"Chris" wrote in message
ups.com...

Mary Fisher wrote:
Wind generated power is not polluting, does not use precious resources
and
does not produce carbon dioxide.

The fact that more energy is probably used manufacturing them than they
will ever produce obviously isn't a consideration.

Give me some authenticated accurate figures for that and I might believe it.

Mary

On Thu, 5 Oct 2006 10:56:11 +0100 someone who may be Roger
wrote this:-

The uninformed might believe your statement indicates that there is
something different about wind turbines. However, it is a fact that
all forms of electricity generation do not produce 100% of their
rated output over a year.

Now that is a statement worthy of a religious fanatic.

Excellent, personal abuse.

There is indeed a crucial difference between wind power and conventional
forms of generation. That is that while wind power is completely at the
mercy of the wind

We know from the work done by Oxford University that a distributed
set of wind farms will always be generating some electricity. Their
study just looked at land based wind farms by the way.

Wind power is diffuse and variable, but that doesn't mean it is not
a useful way of generating large amounts of electricity. It is clear
that with current prices up to 20% of total generation can be by
wind without the need for expensive changes to the electrical
system.

There are plenty of detailed reports on this subject for those with
an open mind to read.

conventional generation can when needed produce 100%
of its rated output on demand at all times except during downtime for
maintenance or repair.

Incorrect. One of the ways that it is incorrect is that, like any
plant, "conventional" generation can suddenly fail without warning.
Small numbers of large power stations introduce greater
vulnerabilities into the system. At the moment the largest failure
to be guarded against is the sudden failure of Sizewell B, followed
by things like the line to France. Fortunately renewables are on
hand to help guard against such things, the rapid start ability of
hydro stations keeps the lights on many times a year during such
failures. They buy enough time to fix the problem or wind up some
other forms of generation.


--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

On 5 Oct 2006 08:34:18 GMT someone who may be "Bob Eager"
wrote this:-

Rudyard Kipling did it in 1903...!

And the monks at Fort Augustus provided a public supply from a hydro
plant in ISTR the 1880s.


--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

On 5 Oct 2006 08:28:44 GMT someone who may be Huge
wrote this:-

The last time I worked it out for here (when our 'leccy bill hit
GBP1K/annum) the repay time for an aerogenerator was in excess of
its expected lifetime. Waste of money.

One could say the same sort of thing about many things people
install, like double glazing. That does not mean it is not worth
doing for other reasons.

We've started an aggressive
electricity saving campaign instead.

Saving is better and cheaper than extra capacity.


--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

Mary Fisher wrote:
"Chris" wrote in message
ups.com...

Mary Fisher wrote:
Wind generated power is not polluting, does not use precious resources
and
does not produce carbon dioxide.

The fact that more energy is probably used manufacturing them than they
will ever produce obviously isn't a consideration.

Give me some authenticated accurate figures for that and I might believe it.


Its your religion not mine.

On Thu, 5 Oct 2006 10:48:16 +0100 someone who may be tony sayer
wrote this:-

Why
feed power from small installs back into the grid why not simply use it
for heating and other purposes on your premises?..

Some do. The problem then becomes what to do with any excess
electricity. Batteries are expensive and bulky and have a host of
environmental problems associated with them. One could heat a
thermal store. An alternative is to use the external system as, in
effect, a battery.

Note also that, done properly, wind installations stabilise the
local electricity system to some extent. This was extensively
studied around the first commercial wind installation at Delabole,
which it is worth remembering is nearing its 15th birthday. The
effect of the wind farm was to stabilise the local system, with the
result that the tap changers in the area operated far less often.


--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

On Oct 5, 12:45 pm, David Hansen
wrote:
On Thu, 5 Oct 2006 10:56:11 +0100 someone who may be Roger
wrote this:-

The uninformed might believe your statement indicates that there is
something different about wind turbines. However, it is a fact that
all forms of electricity generation do not produce 100% of their
rated output over a year.

Now that is a statement worthy of a religious fanatic.Excellent, personal abuse.

There is indeed a crucial difference between wind power and conventional
forms of generation. That is that while wind power is completely at the
mercy of the wind

We know from the work done by Oxford University that a distributed
set of wind farms will always be generating some electricity. Their

Well, obviously, but define "some" as a proportion of total potential
capacity?

study just looked at land based wind farms by the way.

Wind power is diffuse and variable, but that doesn't mean it is not
a useful way of generating large amounts of electricity. It is clear

Its a useful way to generate _some_ electricity. The problem is in the
way that the green zealot are trying to force it upon us whilst
conveniently ignoring all the problems.

that with current prices up to 20% of total generation can be by
wind without the need for expensive changes to the electrical
system.

"up to" being the crucial weasel words. A local shop has a sale with
"up to" 50% off. What does it really mean? If we give over 20% of our
supply to wind power, how much conventional capacity do we need to keep
on-line as cover for when the wind isn't blowing? How much total
potential wind capacity would we need to build to get that 20% when
only a few can actually operate during calm weather?


MBQ

On 2006-10-05 12:45:27 +0100, David Hansen
said:

On Thu, 5 Oct 2006 10:56:11 +0100 someone who may be Roger
wrote this:-

The uninformed might believe your statement indicates that there is
something different about wind turbines. However, it is a fact that
all forms of electricity generation do not produce 100% of their
rated output over a year.

Now that is a statement worthy of a religious fanatic.

Excellent, personal abuse.

Hardly. Just an observation. If you feel that it applies, then that
is really your issue.




There is indeed a crucial difference between wind power and conventional
forms of generation. That is that while wind power is completely at the
mercy of the wind

We know from the work done by Oxford University that a distributed
set of wind farms will always be generating some electricity. Their
study just looked at land based wind farms by the way.

Wind power is diffuse and variable, but that doesn't mean it is not
a useful way of generating large amounts of electricity. It is clear
that with current prices up to 20% of total generation can be by
wind without the need for expensive changes to the electrical
system.

There are plenty of detailed reports on this subject for those with
an open mind to read.

conventional generation can when needed produce 100%
of its rated output on demand at all times except during downtime for
maintenance or repair.

Incorrect. One of the ways that it is incorrect is that, like any
plant, "conventional" generation can suddenly fail without warning.
Small numbers of large power stations introduce greater
vulnerabilities into the system. At the moment the largest failure
to be guarded against is the sudden failure of Sizewell B, followed
by things like the line to France.

Both of which are easily addressed. Duplicate the link from France is
an obvious one.

Fortunately renewables are on
hand to help guard against such things, the rapid start ability of
hydro stations keeps the lights on many times a year during such
failures. They buy enough time to fix the problem or wind up some
other forms of generation.

So build some more schemes like Dinorwic. This was originally intended
to store energy produced by Wylfa and Trawsfynydd.

"Dave Fawthrop" wrote in message
...
On Thu, 5 Oct 2006 04:37:56 +0100, "nightjar" nightjar@insert my surname
here.uk.com wrote:

|
|"Mary Fisher" wrote in message
.net...
|
| "nightjar .uk.com" nightjar@insert my surname here wrote in message
| ...
|
| "dg" wrote in message
| ups.com...
|
| ... How much would the parts be?
|
| Traditionally, you use the generator from an old bus and make the rest
| from other bits of scrap.
|
| If it's so easy I wonder why aren't people doing it ... or perhaps they
| are and are keeping quiet about the results :-)
|
|Generating electricity from wind turbines is not difficult. Generating it
|when you need it is more of a problem. The B&Q turbines rely upon mains
|electricity as a backup. Using the mains supply as the secondary source
used
|to be a breach of most domestic electricity supply contracts and selling
|domestically generated electricity to the generating companies was once
|quite unheard of.

Worse synchronising the turbine output with mains AC at the correct
frequency, phase etc, then adjusting the phase angle to feed power back
into the mains is **VERY** **VERY** difficult. If you do not understand
what I said above it is more or less impossible.

That was the primary reason why it was not permitted when I was in the
electricity supply industry. Loss of revenue was a secondary consideration,
although not a very important one in the days of Nationalisation. We were
capped at 2% profit and the main problem facing the accountants was making
sure we didn't go over that. They even cut prices to stay within the cap,
upon occasion.

Colin Bignell

On Thu, 05 Oct 2006 12:50:28 +0100 David Hansen wrote :
The last time I worked it out for here (when our 'leccy bill hit
GBP1K/annum) the repay time for an aerogenerator was in excess of
its expected lifetime. Waste of money.

One could say the same sort of thing about many things people
install, like double glazing. That does not mean it is not worth
doing for other reasons.

There are other reasons for double glazing, such as improved comfort
and (possibly) reduced maintenance. What other reasons are there for
buying a wind turbine other than saving money: if the answer is
saving the planet, then there are much better ways of using the
money - buy a condensing boiler for your elderly neighbour!

--
Tony Bryer SDA UK 'Software to build on' http://www.sda.co.uk

On 5 Oct 2006 04:22:08 -0700 someone who may be "Chris"
wrote this:-

Wind generated power is not polluting, does not use precious resources and
does not produce carbon dioxide.

The fact that more energy is probably used manufacturing them than they
will ever produce obviously isn't a consideration.

It is a good job you put the word probably into your incorrect
assertion.

This tired old assertion is trotted out by the anti lobby, but it
remains a myth no matter how often it is trotted out.

================================================== ==================

How long does it take for a turbine to 'pay back' the energy used to
manufacture it?

The comparison of energy used in manufacture with the energy
produced by a power station is known as the 'energy balance'. It can
be expressed in terms of energy 'pay back' time, i.e. as the time
needed to generate the equivalent amount of energy used in
manufacturing the wind turbine or power station.

The average wind farm in the UK will pay back the energy used in its
manufacture within six to eight months, this compares favourably
with coal or nuclear power stations, which take about six months.

http://www.bwea.com/ref/faq.html#payback

================================================== ==================

Next contestant please.


--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

David Hansen wrote:

The average wind farm in the UK will pay back the energy used in its
manufacture within six to eight months, this compares favourably
with coal or nuclear power stations, which take about six months.

Next contestant please.


Was actually referring to the ones in B&Q I have no doubt that
commerical wind farms are viable.

On Thu, 05 Oct 2006 11:02:04 GMT, EricP wrote:

Nobody has commented on the "solar panels", a snip at "Only £2498.00".

I stared at it in disbelief. I bought 2x 20 tube units recently at £400 per
panel. B&Q are having a laugh selling flat panels at that price.

On 2006-10-05 13:43:52 +0100, David Hansen
said:

On 5 Oct 2006 04:22:08 -0700 someone who may be "Chris"
wrote this:-

Wind generated power is not polluting, does not use precious resources and
does not produce carbon dioxide.

The fact that more energy is probably used manufacturing them than they
will ever produce obviously isn't a consideration.

It is a good job you put the word probably into your incorrect
assertion.

This tired old assertion is trotted out by the anti lobby, but it
remains a myth no matter how often it is trotted out.

================================================== ==================

How long does it take for a turbine to 'pay back' the energy used to
manufacture it?

The comparison of energy used in manufacture with the energy
produced by a power station is known as the 'energy balance'. It can
be expressed in terms of energy 'pay back' time, i.e. as the time
needed to generate the equivalent amount of energy used in
manufacturing the wind turbine or power station.

The average wind farm in the UK will pay back the energy used in its
manufacture within six to eight months, this compares favourably
with coal or nuclear power stations, which take about six months.

http://www.bwea.com/ref/faq.html#payback

================================================== ==================

Next contestant please.

The discussion is about the toy ones from B&Q, not the ugly industrial
windmills polluting the landscape.

On Thu, 05 Oct 2006 12:47:56 +0100, David Hansen wrote:

On 5 Oct 2006 08:34:18 GMT someone who may be "Bob Eager"
wrote this:-

Rudyard Kipling did it in 1903...!

And the monks at Fort Augustus provided a public supply from a hydro
plant in ISTR the 1880s.

Hmm, Godalming is cited as the first British location to have a public
electricity supply in 1881 using a dynamo provided by Siemens. I believe
I've mentioned this before.

It was remarkably early, since Swan only installed electric lighting at
Cragside in 1880 and Benwell Lamps did not start to manufacture Swan bulbs
until 1881.

The Godalming scheme ran power into private homes, shops and street
lighting using a mix of Swan bulbs and arc lighting.

The porrage eating monks were Johnny-come-latelies not getting around to
generating electricity until 1890.

http://www.kilmorack.com/html/hydro.html

You will note from this page that the Scots came second in generating HEP
(to Godalming) and that the monks were well down the list of achievers.

On Thu, 05 Oct 2006 13:43:52 +0100, David Hansen wrote:

The average wind farm in the UK will pay back the energy used in its
manufacture within six to eight months,

Since the discussion is not about wind farms would you like to try again?

The discussion is about a B&Q device costing £1500 for 1kW of installed
capacity. Now admittedly sale price does not reflect energy input, but the
average punter isn't going to see payback at that price.

On 5 Oct 2006 05:00:09 -0700 someone who may be
wrote this:-

We know from the work done by Oxford University that a distributed
set of wind farms will always be generating some electricity. Their

Well, obviously,

I'm glad you accept that. Not everyone does.

but define "some" as a proportion of total potential capacity?

The answer is not a soundbite. Electrical suppliers model their
systems using complex statistical techniques which attempt to model
the supply and demand of electricity. Matching these two involves a
variety of types of plant.

For integrating wind there are two time periods which particularly
matter in the UK electricity system. The first is an hour or so
ahead. Wind forecasts are already highly accurate over this time
period and the mismatch between forecast and actual output is small,
even when looking at an individual wind farm.

The second time period is the next few days. Wind forecasts are
obviously not as accurate over this time period, but they are
accurate enough to see how much wind is likely to be available and
thus to rearrange other forms of generation as necessary. For
example if wind speeds are going to be low then it gives time to
wind up some superannuated plant and ensure other plant is likely to
be available for example by curtailing minor maintenance.

http://www.ukerc.ac.uk/content/view/258/852 has a fairly detailed
report on the subject for those who are interested. It is not a five
minute read, but it will answer a lot of questions.

Wind power is diffuse and variable, but that doesn't mean it is not
a useful way of generating large amounts of electricity. It is clear

Its a useful way to generate _some_ electricity. The problem is in the
way that the green zealot are trying to force it upon us

If only "green zealots" were that powerful:-)

whilst conveniently ignoring all the problems.

Which are in your opinion?

that with current prices up to 20% of total generation can be by
wind without the need for expensive changes to the electrical
system.

"up to" being the crucial weasel words.

They are not weasel words at all. Up to 20% (or so) of total
generation the cost of incorporating wind generation is small. Above
that one has to modify the electrical system in more expensive ways
so that, at current prices, it becomes uneconomic. 20% is not a
magic figure plucked out of thin air, there has been a lot of work
done on the subject.

A local shop has a sale with
"up to" 50% off. What does it really mean? If we give over 20% of our
supply to wind power, how much conventional capacity do we need to keep
on-line as cover for when the wind isn't blowing?

All forms of electrical generation can fail and need to be backed
up. One of the good things about wind is that the wind doesn't
suddenly stop blowing and because of the distributed nature of wind
farms failure of a line does not knock out much generation. Thus it
is easier to accommodate on the network than some other forms of
generation involving small numbers of large stations.

Up to 20% any extra backup, over and above that already provided for
other forms of generation, is negligible. Above 20% rising amounts
of backup are one of the reasons costs rise.

How much total
potential wind capacity would we need to build to get that 20% when
only a few can actually operate during calm weather?

See the report for some information on this.

There are currently 135 wind projects with 1726 turbines operational
according to http://www.bwea.com/ukwed/index.asp ranging from large
sites such as Black Law to individual turbines.


--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

On Thu, 05 Oct 2006 11:02:04 GMT someone who may be EricP
wrote this:-

With the claims they are making, the things will sell. This "30%"
business, and having it injected straight into the house mains will
camoflage the failings of the things. Only when buyers notice no
difference in their electricity bills will the con be found out,

Any evidence to back up your assertion?


--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

On 5 Oct 2006 05:48:53 -0700 someone who may be "Chris"
wrote this:-

Was actually referring to the ones in B&Q

That doesn't alter the fact that the energy used to make them will
be recovered, except in the strangest of circumstances.

Obviously it is likely that such turbines will not be ideally
situated in many cases and they will not be as efficient at
converting wind into electricity as a large turbine. Thus it is
likely that they will take longer to recover the energy used to make
them, let's say a year to be generous.

That is an energy balance however. A financial balance is a
different thing. I expect that, as with almost anything else, the
early adopters will have other reasons for purchase and that the
result of their purchases will be to drive the cost down.


--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

On Thu, 05 Oct 2006 13:42:35 +0100 someone who may be Tony Bryer
wrote this:-

There are other reasons for double glazing, such as improved comfort
and (possibly) reduced maintenance. What other reasons are there for
buying a wind turbine other than saving money:

It is one way of reducing greenhouse gas emissions. There are other
ways too, but it is not an either or thing.


--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

The message
from David Hansen contains these words:

The uninformed might believe your statement indicates that there is
something different about wind turbines. However, it is a fact that
all forms of electricity generation do not produce 100% of their
rated output over a year.

Now that is a statement worthy of a religious fanatic.

Excellent, personal abuse.

No so. It was a statement of fact. However your remark above that
prompted mine does rank as abuse, abuse to all those fair minded folk
who can see through your squalid little ruse.

There is indeed a crucial difference between wind power and conventional
forms of generation. That is that while wind power is completely at the
mercy of the wind

We know from the work done by Oxford University that a distributed
set of wind farms will always be generating some electricity. Their
study just looked at land based wind farms by the way.

More obfuscation. Some doesn't have to be very much at all and at the
other end of the scale there are wind speeds that should prevent any
generation whatsoever.

Wind power is diffuse and variable, but that doesn't mean it is not
a useful way of generating large amounts of electricity. It is clear
that with current prices up to 20% of total generation can be by
wind without the need for expensive changes to the electrical
system.

You don't consider wind turbines as expensive changes to the electrical
system? No, of course not, just plant the turbine seedling and it will
grow into a fully functioning generator under the influence of nothing
more than water and sunlight.

There are plenty of detailed reports on this subject for those with
an open mind to read.

More personal abuse.

Of all the forms of 'free' energy wind is the least deserving of any
support. As you mention below hydro is already well established and in
the hillier parts of the UK it has much more scope for domestic use at
lower cost and much greater reliability. Tides are 100% reliable and
tidal power has the scope to dwarf the puny output of wind farms. And
even wave power is a better bet than wind power.

conventional generation can when needed produce 100%
of its rated output on demand at all times except during downtime for
maintenance or repair.

Incorrect. One of the ways that it is incorrect is that, like any
plant, "conventional" generation can suddenly fail without warning.
Small numbers of large power stations introduce greater
vulnerabilities into the system. At the moment the largest failure
to be guarded against is the sudden failure of Sizewell B, followed
by things like the line to France. Fortunately renewables are on
hand to help guard against such things, the rapid start ability of
hydro stations keeps the lights on many times a year during such
failures. They buy enough time to fix the problem or wind up some
other forms of generation.

That is no justification for claiming my statement was incorrect. You
need to think a little more deeply about what you are responding to.

I would be very interested to see a list of all those "many times a
year" failures that you claim hydro stations are protecting us from.

Incidentally while hydro schemes may indeed help in the event of a very
occasional major emergency at a large conventional power station wind
power would be a very uncertain element to rely on in any emergency.

--
Roger Chapman

On Thu, 5 Oct 2006 13:02:36 UTC, Steve Firth
wrote:

On Thu, 05 Oct 2006 12:47:56 +0100, David Hansen wrote:

On 5 Oct 2006 08:34:18 GMT someone who may be "Bob Eager"
wrote this:-

Rudyard Kipling did it in 1903...!

And the monks at Fort Augustus provided a public supply from a hydro
plant in ISTR the 1880s.

Hmm, Godalming is cited as the first British location to have a public
electricity supply in 1881 using a dynamo provided by Siemens. I believe
I've mentioned this before.

I was really referring to a single, private house.

--
The information contained in this post is copyright the
poster, and specifically may not be published in, or used by
Avenue Supplies, http://avenuesupplies.co.uk

David Hansen wrote:
different thing. I expect that, as with almost anything else, the
early adopters will have other reasons for purchase and that the
result of their purchases will be to drive the cost down.

Two short planks spring immediatly to mind.

On 2006-10-05 14:30:37 +0100, David Hansen
said:

On 5 Oct 2006 05:48:53 -0700 someone who may be "Chris"
wrote this:-

Was actually referring to the ones in B&Q

That doesn't alter the fact that the energy used to make them will
be recovered, except in the strangest of circumstances.

Obviously it is likely that such turbines will not be ideally
situated in many cases and they will not be as efficient at
converting wind into electricity as a large turbine. Thus it is
likely that they will take longer to recover the energy used to make
them, let's say a year to be generous.

That is an energy balance however. A financial balance is a
different thing. I expect that, as with almost anything else, the
early adopters will have other reasons for purchase and that the
result of their purchases will be to drive the cost down.

If there were enough, that might be true. However, at £1500 this is
not going to produce a significant sales volume.

It has taken legislation to introduce condensing boilers being
virtually mandatory, and in that case there almost always is a clear
financial gain.

Set against this backdrop, these toy windmills really don't stand much
of a chance. £300 installed and they might be interesting as a
curiosity to those with disposable income, but £1500 is a different
discussion altogether.

The reality is that the vast majority of people are only eco-minded to
the extent that it doesn't inconvenience them and solutions will stand
up to financial justification.

The message
from David Hansen contains these words:

The average wind farm in the UK will pay back the energy used in its
manufacture within six to eight months, this compares favourably
with coal or nuclear power stations, which take about six months.

I've no doubt said it before but I for one have no confidence in the
judgement or indeed the probity of anyone who would claim that 6 to 8
months compares favourably to about 6 months unless of course the
favourable outcome was 8 months.

--
Roger Chapman

On Thu, 05 Oct 2006 09:25:19 +0100, David Hansen
wrote:

On Wed, 04 Oct 2006 21:05:03 +0100 (BST) someone who may be "Dave
Liquorice" wrote this:-

As I see it wind is not really the way to go. To get sensible outputs you
have to have huge devices(*) that on average only generate 1/3 to 1/4 of
their rated output over a year.

The uninformed might believe your statement indicates that there is
something different about wind turbines. However, it is a fact that
all forms of electricity generation do not produce 100% of their
rated output over a year.

Yes they can, It's purely a mathematical exercise as it depends on how
you rate them. Although not electricity generation related, the space
shuttle main engines can for instance can produce 109% of their rated
thrust.

The annual load factor on some UK coal/gas generation has certainly
been above 90%, and I'd hazard a guess that some nuclear generation
runs even higher - albeit in re-rated from the original design output
due to engineering considerations, also a great many hydro plants run
at as near as dammit 100%, the only time they are off the bars is for
statutory testing of overspeed devices etc.

--