http://www.bwea.com/pdf/mid%20wales%20microwind.pdf

There are a couple of commercial windpower systems (i.e windsave)

http://www.energytech.co.uk/Windsave%20040205.pdf

The concept seems simple enough, there are a couple of homebrew turbines out
there (mast mounted), but afaik not one that can be connected as easily.
Despite this the system is not avaliable for DIY installation.

Would a homebrew roof mount system be a reasonable project?

On Tue, 25 Oct 2005 12:01:21 GMT, "Jim" Jim
wrote:

http://www.bwea.com/pdf/mid%20wales%20microwind.pdf

There are a couple of commercial windpower systems (i.e windsave)

http://www.energytech.co.uk/Windsave%20040205.pdf

The concept seems simple enough, there are a couple of homebrew turbines out
there (mast mounted), but afaik not one that can be connected as easily.
Despite this the system is not avaliable for DIY installation.

Would a homebrew roof mount system be a reasonable project?


A roof mount is NOT an efficient place for a wind turbine. The turbine
needs a smooth flow of air. The air will become unsmooth some distance
before it reaches the roof.

Its easy enough to make for a small turbine, but are you sure that
your building can take the strain ?

I have always felt a telegraph pole would be an ideal mount for a
small turbine.

Rick

Rick wrote:
On Tue, 25 Oct 2005 12:01:21 GMT, "Jim" Jim
wrote:

http://www.bwea.com/pdf/mid%20wales%20microwind.pdf

There are a couple of commercial windpower systems (i.e windsave)

http://www.energytech.co.uk/Windsave%20040205.pdf

The concept seems simple enough, there are a couple of homebrew
turbines out there (mast mounted), but afaik not one that can be
connected as easily. Despite this the system is not avaliable for
DIY installation.

Would a homebrew roof mount system be a reasonable project?


A roof mount is NOT an efficient place for a wind turbine.

given the requirements of the OP it most certainly is.

The turbine
needs a smooth flow of air.

no it doesn't, all it needs is sufficient airflow to turn it.

The air will become unsmooth some distance before it reaches the roof.

so ?

Its easy enough to make for a small turbine, but are you sure that
your building can take the strain ?

eh ? a 1-2Kw wind genny will destabilise a few hundred tons of brick,
mortar and slate ? even in the hebrides, that's a nonsense.

On Tue, 25 Oct 2005 12:01:21 GMT, "Jim" Jim
wrote:

http://www.bwea.com/pdf/mid%20wales%20microwind.pdf

There are a couple of commercial windpower systems (i.e windsave)

http://www.energytech.co.uk/Windsave%20040205.pdf

The concept seems simple enough, there are a couple of homebrew turbines out
there (mast mounted), but afaik not one that can be connected as easily.
Despite this the system is not avaliable for DIY installation.

Would a homebrew roof mount system be a reasonable project?

I'm pretty sure this has been discussed before and a large thermal
store was suggested. This seems reasonable since an immersion heater
isn't too sensitive to variations in voltage - (i.e. + or - 20 %
wouldn't matter much).

A homebrew roof mount system would be a very interesting project.
Reasonable is a matter for you to decide! :-)

Mr F.

Jim wrote:
http://www.bwea.com/pdf/mid%20wales%20microwind.pdf

There are a couple of commercial windpower systems (i.e windsave)

http://www.energytech.co.uk/Windsave%20040205.pdf

The concept seems simple enough, there are a couple of homebrew turbines out
there (mast mounted), but afaik not one that can be connected as easily.
Despite this the system is not avaliable for DIY installation.

Would a homebrew roof mount system be a reasonable project?

Does this help?

http://www.cat.org.uk/catpubs/book.tmpl?sku=ww

MBQ

On Tue, 25 Oct 2005 12:19:19 GMT, "news" wrote:

Rick wrote:
On Tue, 25 Oct 2005 12:01:21 GMT, "Jim" Jim
wrote:

http://www.bwea.com/pdf/mid%20wales%20microwind.pdf

There are a couple of commercial windpower systems (i.e windsave)

http://www.energytech.co.uk/Windsave%20040205.pdf

The concept seems simple enough, there are a couple of homebrew
turbines out there (mast mounted), but afaik not one that can be
connected as easily. Despite this the system is not avaliable for
DIY installation.

Would a homebrew roof mount system be a reasonable project?


A roof mount is NOT an efficient place for a wind turbine.

given the requirements of the OP it most certainly is.

The turbine
needs a smooth flow of air.

no it doesn't, all it needs is sufficient airflow to turn it.


Need may be have been the wrong word. A smooth airflow has more power
obtainable from it, than a disturbed airflow.


The air will become unsmooth some distance before it reaches the roof.

so ?

Less power will be obtainable from a turbine mounted on a roof, than
one mounted on a pole.

Its easy enough to make for a small turbine, but are you sure that
your building can take the strain ?

eh ? a 1-2Kw wind genny will destabilise a few hundred tons of brick,
mortar and slate ? even in the hebrides, that's a nonsense.


If the mount was at the bottom of the wall, then maybe it would have
to effect the whole wall, but the mount will likley be attached at the
top of the wall, where only a few bricks (for example) will need to
come loose.

"Jim" Jim wrote in message
. uk...
http://www.bwea.com/pdf/mid%20wales%20microwind.pdf

There are a couple of commercial windpower systems (i.e windsave)

http://www.energytech.co.uk/Windsave%20040205.pdf

The concept seems simple enough, there are a couple of homebrew turbines
out there (mast mounted), but afaik not one that can be connected as
easily. Despite this the system is not avaliable for DIY installation.

Would a homebrew roof mount system be a reasonable project?


Actually, putting a turbine on the roof ridge might be a good idea, as the
roof acts like a one-sided venturi and speeds the air up ( Bernoulli's Law
and all that ).

I would be concerned about the architectural acne side of things - it won't
look good, but fine if you're out in the boondocks.

Andy.

"Jim" Jim wrote in message
. uk...
http://www.bwea.com/pdf/mid%20wales%20microwind.pdf

There are a couple of commercial windpower systems (i.e windsave)

http://www.energytech.co.uk/Windsave%20040205.pdf

The concept seems simple enough, there are a couple of homebrew turbines
out there (mast mounted), but afaik not one that can be connected as
easily. Despite this the system is not avaliable for DIY installation.

Would a homebrew roof mount system be a reasonable project?

I just happened to be browsing the BBC site this morning and saw this about
an inventor needing planning permission for his wind turbine.

http://news.bbc.co.uk/1/hi/england/london/4373148.stm

rusty

Rick wrote:
On Tue, 25 Oct 2005 12:19:19 GMT, "news" wrote:

Rick wrote:
On Tue, 25 Oct 2005 12:01:21 GMT, "Jim" Jim
wrote:

http://www.bwea.com/pdf/mid%20wales%20microwind.pdf

There are a couple of commercial windpower systems (i.e windsave)

http://www.energytech.co.uk/Windsave%20040205.pdf

The concept seems simple enough, there are a couple of homebrew
turbines out there (mast mounted), but afaik not one that can be
connected as easily. Despite this the system is not avaliable for
DIY installation.

Would a homebrew roof mount system be a reasonable project?


A roof mount is NOT an efficient place for a wind turbine.

given the requirements of the OP it most certainly is.

The turbine
needs a smooth flow of air.

no it doesn't, all it needs is sufficient airflow to turn it.


Need may be have been the wrong word. A smooth airflow has more power
obtainable from it, than a disturbed airflow.

smooth airflow doesn't matter, as long as the required revolutions are achieved
the required output will be produced. 'smoothness' is irrelevant.

The air will become unsmooth some distance before it reaches the
roof.

so ?

Less power will be obtainable from a turbine mounted on a roof, than
one mounted on a pole.

so, a turbine mounted on a pole, in a valley, will make less power
than a turbine mounted on a gable end of a house on a hill ?

here comes the science !! ~~~~

If the mount was at the bottom of the wall, then maybe it would have
to effect the whole wall, but the mount will likley be attached at the
top of the wall, where only a few bricks (for example) will need to
come loose.

aside for the affect/effect issue and the 'likley' situation:

hahahahahahaha !!

"news" wrote in message
...
Rick wrote:
On Tue, 25 Oct 2005 12:19:19 GMT, "news" wrote:

Rick wrote:
On Tue, 25 Oct 2005 12:01:21 GMT, "Jim" Jim
wrote:

http://www.bwea.com/pdf/mid%20wales%20microwind.pdf

There are a couple of commercial windpower systems (i.e windsave)

http://www.energytech.co.uk/Windsave%20040205.pdf


So for £1000 capital outlay and a further £1000 for the inverter (£2000) he
produces some 600 KwH per year at say 7p per KwH which is £42 worth of
electricity a year which is only (2000/42) 47 YEARS to just break even,
assuming no maintenance and other problems..... He will probably die
before breaking even, especially if he falls off the ladder installing it.

Is it any wonder why there is not a rush to
do this on economic grounds ?

About the best I have seen are geothermal systems for house heating, but
even this has ongoing maintenance issues, a long break even time and a
requirement for at least a largish plot of land to dig trenches into for the
collectors, or a bore hole...
However, it is a lot closer to being viable in the nearer future...

Nick.

Nick wrote:
(about house-top wind powered generators)
So for £1000 capital outlay and a further £1000 for the inverter (£2000) he
produces some 600 KwH per year at say 7p per KwH which is £42 worth of
electricity a year which is only (2000/42) 47 YEARS to just break even,
assuming no maintenance and other problems.....

I'd noted that, also...

Is it any wonder why there is not a rush to
do this on economic grounds ?

Is it viable on resource grounds? How much energy and resource does it
take to make one of these things?

news wrote:

Its easy enough to make for a small turbine, but are you sure that
your building can take the strain ?

eh ? a 1-2Kw wind genny will destabilise a few hundred tons of brick,
mortar and slate ? even in the hebrides, that's a nonsense.

I can't remember which site, but at least one of the major domestic
turbine manufacturers stipulates their turbines should not be installed
on a building constructed using lime mortar. Turbines are far from
vibration (and noise) free, and can certainly cause damage to a
masonray wall over time.

LGF

I work on a figure of around 10% for the cost of the embodied energy of
most manufactured goods. So, within somewhere between 5 and 10 years,
you can be fairly certain that the device has repayed it's energy of
manufacture/transportation/installation. I can't help but think that
domestic wind turbines can be no more than a rich person's status
symbol.

What I find most striking is the discrepancy between the output from
actual installations and the marketing hype. I really don't know how
they get away with it! I

"Nick" wrote:

So for £1000 capital outlay and a further £1000 for the inverter (£2000) he
produces some 600 KwH per year at say 7p per KwH which is £42 worth of
electricity a year which is only (2000/42) 47 YEARS to just break even,
assuming no maintenance and other problems..... He will probably die
before breaking even, especially if he falls off the ladder installing it.

Is it any wonder why there is not a rush to
do this on economic grounds ?

The 7p per kWh is this years price. The price rises on their way over
the coming years could give you payback in a few months.......of
course doing a Rod Hull is slightly more likely. ;-)


--

rusty wrote:

I just happened to be browsing the BBC site this morning and saw this about
an inventor needing planning permission for his wind turbine.

http://news.bbc.co.uk/1/hi/england/london/4373148.stm

rusty

inventor?

In article . com,
writes
rusty wrote:

I just happened to be browsing the BBC site this morning and saw this about
an inventor needing planning permission for his wind turbine.

http://news.bbc.co.uk/1/hi/england/london/4373148.stm

rusty

inventor?

Course this begs a question...

Suppose you have a small village of say 200 houses or family units. Now
what would be more efficient to have 200 small home sized ones, or one
big 'un mounted outside the village which supplied the whole lot?....
--
Tony Sayer

DIY windy miller:
http://www.dnisbet2.uklinux.net/

"Phil" wrote:

DIY windy miller:
http://www.dnisbet2.uklinux.net/

The website looks distinctly DIY too.


--

On Tue, 25 Oct 2005 17:35:48 +0100, Chris Bacon
wrote:

Nick wrote:
(about house-top wind powered generators)
So for £1000 capital outlay and a further £1000 for the inverter (£2000) he
produces some 600 KwH per year at say 7p per KwH which is £42 worth of
electricity a year which is only (2000/42) 47 YEARS to just break even,
assuming no maintenance and other problems.....

I'd noted that, also...

Is it any wonder why there is not a rush to
do this on economic grounds ?

Is it viable on resource grounds? How much energy and resource does it
take to make one of these things?

My place in in one of the Welsh Assembly TAN-8 areas, where they wish
to promote windmill buliding. So I phoned up a few suppliers for a
10KW windmill, and none would sell me one. They said the wind at my
house was too low to make it worth the government giving me the 10K
grant towards the machine. So why did the Welsh assemply put the TAN-8
area here ?

Rick

Nick wrote:
"news" wrote in message
...
Rick wrote:
On Tue, 25 Oct 2005 12:19:19 GMT, "news" wrote:

Rick wrote:
On Tue, 25 Oct 2005 12:01:21 GMT, "Jim" Jim
wrote:

http://www.bwea.com/pdf/mid%20wales%20microwind.pdf

There are a couple of commercial windpower systems (i.e windsave)

http://www.energytech.co.uk/Windsave%20040205.pdf


So for £1000 capital outlay and a further £1000 for the inverter (£2000) he
produces some 600 KwH per year at say 7p per KwH which is £42 worth of
electricity a year which is only (2000/42) 47 YEARS to just break even,
assuming no maintenance and other problems..... He will probably die
before breaking even, especially if he falls off the ladder installing it.

Is it any wonder why there is not a rush to
do this on economic grounds ?

About the best I have seen are geothermal systems for house heating, but
even this has ongoing maintenance issues, a long break even time and a
requirement for at least a largish plot of land to dig trenches into for the
collectors, or a bore hole...
However, it is a lot closer to being viable in the nearer future...

There was an item on the beeb about it today.

At present professional installations are way over th hoped for
eventual cost of them if we all splurge. In which case it would be
worth while if you lived in a suitable area:
http://groups.google.com/group/alt.t...0cce4b38999b96

We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember "Jim" Jim
saying something like:

Would a homebrew roof mount system be a reasonable project?

If you really want a constant thrumming racket, yes.
--

Dave

Jim wrote:
snip

Would a homebrew roof mount system be a reasonable project?

Sorry - I came to this late - I am seriously looking for a device to
install here at home and it seems to me that only 2 makers are in the
running, but I would like to be proved wrong.

Renewable Devices (hooked up with SSE to the tune of £9M) and Windsave
(currently looking to float for £55M).

What sets them apart is the connection directly into the mains so they
export energy when it is not being used internally (no batteries).
Supposedly there is a quicker payback.

All the above auguments about efficiency, turbulence, noise, etc apply.

What makes them less than ideal consumer products is the price. I
calculate that the RD genny comes in at £9,000 installed. OK, grants
& payback may offset that, but that is not an attractive price for
1.5KW.

Similarly, but better positioned, is the Windsave at about £1500 for
1KW.

Come on. Whereas this thread is engineering based, due to the
interests of contributors, and the 'big windfarm debate' across the
country is landscape based, I feel this is a marketing issue. If these
were made in volume the cost should not be more than a dishwasher.
Every house should have one.

If you look at a micro wind generator there is not much that is more
complex than is found in a DVD player or such common appliance.

The argument should be to get these into volume production, get people
installing them and the energy equation will change rapidly.

On 17 Nov 2005 14:24:16 -0800, "OLDTOWNGUY" wrote:

If you look at a micro wind generator there is not much that is more
complex than is found in a DVD player or such common appliance.

The argument should be to get these into volume production, get people
installing them and the energy equation will change rapidly.

The complexity for the connection apparatus to the grid system are one
of the killer's price wise. Corners cannot be cut as back feeding
after a system fault, particularly from numerous sources could kill.
Also one thing conveniently overlooked is that the ratings quoted for
wind turbines are *always* without exception hopelessly overstated.

Unless you want to go completely off grid forever and all that entails
then the planning implications of huge (or even less than huge)
amounts of wind generation are immense, the consumer will still need
to stump up the costs for conventional plant lying idle for the day
the wind drops. If wind renewable's expand significantly more than
the current renewable's target and compose a large percentage of that
total (as they currently do) the **** would start hitting the fan as
reality bit.

So no amount of windmill building, even up to and beyond T B Liar's
targets will keep the lights on. Tidal barrages might have some future
but again the environmentalists will moan. The ONLY possible future is
nuclear. It will really upset the environmentalists but unless action
is taken now (a firm decision to press the button for a new generation
of multiple nukes in the next 12-24 months) the lights will go out in
a couple of decades (or less).


--

On Thu, 17 Nov 2005 23:36:23 +0000 someone who may be Matt
wrote this:-

the planning implications of huge (or even less than huge)
amounts of wind generation are immense, the consumer will still need
to stump up the costs for conventional plant lying idle for the day
the wind drops.

The report at http://www.eci.ox.ac.uk/renewables/ukwind disagrees
with you.

On the myth of wind power being unavailable for long periods it has
this to say:

"Low wind speed conditions affecting 90% or more of the UK would
occur in around one hour every five years during winter;
The chance of wind turbines shutting down due to high wind speed
conditions is very rare - high winds affecting 40% or more of the UK
would occur in around one hour every 10 years."

On the myth of wild fluctuations in wind output it has this to say:

"The most likely change in power output from a diversified wind
power system from one hour to the next is less than plus or minus
2.5% of the total installed wind power capacity. Larger changes from
one hour to the next do occur - a change in hourly output equal to
around plus or minus 20% of the installed wind power capacity is
likely to happen about once per year."

Note that wind forecasting for the next hour or two is highly
accurate and hydro and gas turbine plants can start within a couple
of minutes. The anti-wind claim that coal fired plant running
constantly in reserve is necessary in case the wind suddenly stops
blowing is a myth.

As Energy Minister Malcolm Wicks is reported as saying:

"The only sensible debate about energy is one based on the facts.
This new research is a nail in the coffin of some of the exaggerated
myths peddled by opponents of wind power."

http://www.bwea.com/media/news/141105.html


As for conventional plant lying idle, unless wind exceeds around 20%
of total generation there is negligible extra plant than there would
be if that 20% was generated by nuclear, coal or whatever.

http://www.sd-commission.org.uk/page...list/wind.html and
navigate down to the "Download our booklet 'Wind Power: Your
Questions Answered', for householders" link then Section 5 of the
booklet.

"Many people wonder what happens when the wind doesn’t blow. The
truth is that the national grid system is already designed to cope
with large fluctuations in supply and demand. It must deal with
rapid surges in demand – such as during the breakfast period or at
the end of a televised football match when millions of kettles are
used at the same time.

"National Grid Company has confirmed that accommodating significant
amounts of wind capacity on the electricity system is unlikely to
pose any major operational challenges. Indeed there’s no technical
limit on the amount of wind that can be absorbed by the system – the
issue is simply one of cost.

"Wind power is becoming easier to predict. As it becomes more
dispersed around the country it is increasingly unlikely that all
the UK’s wind farms will be out of action at the same time. To cover
for any shortfall will require a small increase in the ‘balancing
services’ that are routinely used by the network operator. This, and
issues such as grid reinforcement, will add a small amount to the
cost of electricity, which is explained below.

"How will increased use of wind power affect my electricity bill?

"Let’s assume that by 2020, we have achieved the Government’s goal
of generating 20% of our electricity by renewable means – and this
done solely via wind power. In this case, the extra cost to
consumers of integrating wind power would be about 3.8% of the
current domestic charge – around £13 on the average annual UK bill.
If the environmental benefit of reduced carbon dioxide emissions is
calculated and included, the additional ‘social’ cost of wind power
will be less – possibly zero."

Those who want further information can go to the "Download our full
report 'Wind Power in the UK'" link. Section 3 of the report is the
place that covers this issue.


For some information specifically on microgeneration
http://www.sd-commission.org.uk/news...KMFYS8-5OZZIS2
is a good start.



--
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 Matt contains these words:

So no amount of windmill building, even up to and beyond T B Liar's
targets will keep the lights on. Tidal barrages might have some future
but again the environmentalists will moan. The ONLY possible future is
nuclear. It will really upset the environmentalists but unless action
is taken now (a firm decision to press the button for a new generation
of multiple nukes in the next 12-24 months) the lights will go out in
a couple of decades (or less).

Tidal barrages would be a much better bet than wind power. Not only
would a relatively few schemes producing a serious amount of power
suffice their output would be entirely predictable and if strategically
placed round the coast provide continuous cover.

--
Roger Chapman

The message
from David Hansen contains these words:

"Low wind speed conditions affecting 90% or more of the UK would
occur in around one hour every five years during winter;
The chance of wind turbines shutting down due to high wind speed
conditions is very rare - high winds affecting 40% or more of the UK
would occur in around one hour every 10 years."

Never trust politicians statistics. It doesn't take anywhere near that
extreme of wind conditions to cripple the power output from wind farms.
And stationary highs with very light winds over most of the country (as
at present) are a feature of the UK weather.

On the myth of wild fluctuations in wind output it has this to say:

"The most likely change in power output from a diversified wind
power system from one hour to the next is less than plus or minus
2.5% of the total installed wind power capacity. Larger changes from
one hour to the next do occur - a change in hourly output equal to
around plus or minus 20% of the installed wind power capacity is
likely to happen about once per year.

Rate of change in output is a red herring. What matters is the amount of
conventional capacity that has to be kept on standby and/or used to
produce the difference between wind farm capacity and actual output.

Has anybody got a figure for the actual average output of the current
wind farms as compared with their theoretical maximum?

--
Roger Chapman

David Hansen wrote:
On Thu, 17 Nov 2005 23:36:23 +0000 someone who may be Matt
wrote this:-

the planning implications of huge (or even less than huge)
amounts of wind generation are immense, the consumer will still need
to stump up the costs for conventional plant lying idle for the day
the wind drops.

The report at http://www.eci.ox.ac.uk/renewables/ukwind disagrees
with you.

On the myth of wind power being unavailable for long periods it has
this to say:

SNIP

What it doesn't say is how much land will be required by
these windmills to generate sufficient power to make the prospect of
wind-power actually feasible. The authors of the report neatly sidestep the
issue.

Rob

On 17 Nov 2005 18:07:38 -0800, wrote:

Imho no lights will go out though, prices (and energy saving drives)
will take care of that.

As a "for instance" the electricity selling price (not the cost of
generation) just dropped straight through the floor around five years
ago. As a result a major power station (7% of the installed UK
capacity) went bankrupt and was repossessed by the bankers,
fortunately they had difficulty offloading it as scrap otherwise we
really could be in the ****. That same power station is now on the
market and in a bidding war attracting offers around GBP2bn. Until
there is a coherent national energy policy and stable market
conditions no investor (other than one who has been siphoning off IMF
funds) will contemplate entering the market.

The Tories started this off in the 80's with the persecution of the
miners at any cost increasing dependence on imported fossil fuels, the
waste of North Sea oil revenues on unemployment benefit was deemed
more acceptable than state funded/assisted construction projects that
would provide real labour opportunities and provide something long
lasting and of value to the nation (like a decent rail system or 4
lane M1 etc) The Tories then carried it on into the 90's with
privatisation of the gas and electricity systems and the phoney sell
off of the nuclear industry. The tosser Tory Clone T B Liar can't even
get his head around the rapidly impending crisis after "eight glorious
years"


--

On Fri, 18 Nov 2005 09:03:11 +0000, David Hansen
wrote:

On Thu, 17 Nov 2005 23:36:23 +0000 someone who may be Matt
wrote this:-

the planning implications of huge (or even less than huge)
amounts of wind generation are immense, the consumer will still need
to stump up the costs for conventional plant lying idle for the day
the wind drops.

The report at http://www.eci.ox.ac.uk/renewables/ukwind disagrees
with you.

On the myth of wind power being unavailable for long periods it has
this to say:

"Low wind speed conditions affecting 90% or more of the UK would
occur in around one hour every five years during winter;
The chance of wind turbines shutting down due to high wind speed
conditions is very rare - high winds affecting 40% or more of the UK
would occur in around one hour every 10 years."
On the myth of wild fluctuations in wind output it has this to say:

"The most likely change in power output from a diversified wind
power system from one hour to the next is less than plus or minus
2.5% of the total installed wind power capacity. Larger changes from
one hour to the next do occur - a change in hourly output equal to
around plus or minus 20% of the installed wind power capacity is
likely to happen about once per year."

Those figures are just so ridiculous to be even considered. (see the
current weather conditions in the UK and then go for a drive to
observe the distinct lack of rotation of wind turbines)

"National Grid Company has confirmed that accommodating significant
amounts of wind capacity on the electricity system is unlikely to
pose any major operational challenges. Indeed there’s no technical
limit on the amount of wind that can be absorbed by the system – the
issue is simply one of cost.

That I do know to be incorrect, the people that do know the real facts
have in recent years been marginalised to stop them kicking up a fuss
(quite common in the UK energy business) In a future interconnected
market with significant hydro generation import from Norway it might
just be feasible but there IS a limit and suggesting there isn't is
less than honest and technically incorrect. Even with a fully
interconnected system the drawbacks of significant wind generation are
being felt in at least three European countries. If anything they are
now retreating from their previously declared intentions.

Look at the current weather pattern across the UK. A high pressure
area such as is currently being encountered is rather common in
winter. The wind speeds at the moment (5-6 mph across much of the UK
as reported by the met office) are such that wind generation is making
no useful contribution on what is quite probably the highest demand
day of the winter so far. So either you swamp each and every hillside
with turbines on the expectation of some wind, somewhere at enormous
capital and environmental cost - or you will freeze UNLESS alternative
generation is available.

From the BBC weather site, current and predicted conditions:

Friday:
http://www.bbc.co.uk/weather/charts/...y_05111812.jpg
(Wind speed too low, running out of water at Dinorwig top lake, lights
go out later, Tory B Liar leaves for Caribbean hideaway)

Saturday:
http://www.bbc.co.uk/weather/charts/...y_05111912.jpg
(Wind speed too low, lights out across the UK as numerous gas fired
generators loose gas feeds, Prescott says no problem, everything is
going as planned)

Sunday:
http://www.bbc.co.uk/weather/charts/...y_05112012.jpg

(Wind picking up slightly in Scotland and Northern Ireland - lights
still out in England and Wales, Prescott leaves for the heat of
Iceland)

Monday:
http://www.bbc.co.uk/weather/charts/...y_05112112.jpg

(Wind speed too low again, lights distinctly out in England and Wales
again, hundreds of oap's start dying, No one from government available
to comment)

Nukes are the ONLY way forward.

--

On Fri, 18 Nov 2005 11:27:45 GMT someone who may be
wrote this:-

Roger wrote:

Tidal barrages would be a much better bet than wind power. Not only
would a relatively few schemes producing a serious amount of power
suffice their output would be entirely predictable and if strategically
placed round the coast provide continuous cover.

Underwater turbines avoid the construction of a large dam and the
objections of the bird lobby that this involves. An experimental one
worked well enough to allow a second phase to be started. AFAIR this
will be in Strangford Lough http://www.marineturbines.com/home.htm

Wave power is another possibility. I remember lots of work being done on
'nodding donkey' devices in the 70s, what became of them?

The nuclear "industry" was asked to evaluate the most promising,
Salter's Duck. Surprise, surprise they recommended against it and in
favour of nuclear power stations. Since then there has been a degree
of work and the first commercial wave farm is being planned/about to
be built. http://www.oceanpd.com/


--
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 Fri, 18 Nov 2005 10:31:24 GMT someone who may be Roger
wrote this:-

Never trust politicians statistics.

I don't.

Are you suggesting that the University of Oxford
Environmental Change Institute are politicians?

Rate of change in output is a red herring. What matters is the amount of
conventional capacity that has to be kept on standby and/or used to
produce the difference between wind farm capacity and actual output.

In the full SDC report I referred to one will read:

"3.5 Capacity and flexibility of wind power

"The need for reserves

"It is commonly assumed that adding significant wind power capacity
to the electricity system will lead to a large expansion in the need
for balancing services, particularly reserves. This is due to an
implicit assumption that the intermittent output of wind power
results in the need for large amounts of reserves devoted entirely
to providing standby power for wind output – this is often referred
to as ‘backup plant’. Therefore, if the average output of wind plant
is 35% of its rated output (its capacity factor), the remaining 65%
must be provided as reserve, or backup capacity.

"This reasoning is seriously flawed, for three key reasons:

"• No generating plant is 100% reliable. Therefore, reserves are
required to cover for unexpected outages on all plants.

"• The rated capacity of the total installed wind plant is of minor
interest to system operators, who make supply security assessments
based on estimates of overall statistical probabilities for the
complete generating mix. This leads to the concept of ‘capacity
values’, described below.

"• Wind power is often described as ‘intermittent’, which implies a
high level uncertainty as to its actual output, but it can be quite
accurately forecast in the appropriate timeframes for balancing
electricity supply. A more precise term might be ‘variable’,
especially when considering aggregate output, which benefits from
the wide distribution of wind turbines across the country.

"Instead, system operators assign all generating plant a ‘capacity
value’ (often called ‘capacity credit’), which refers to the ability
of that plant to contribute firm capacity to the overall system.
High availability plant such as combined cycle gas turbine (CCGT)
can have a capacity value of up to 90%, meaning 10 GW of gas plant
would be treated as providing the system with 9 GW of firm capacity
– the remaining 1 GW allows for outages, both scheduled and
unscheduled. Existing nuclear plant in the UK has recently shown
lower capacity values of 75%, due to a number of problems at
individual plants.

"No plant has a capacity value of 100%, because there will always be
some statistical probability that it will not be available when
required. When determining reserve requirements, system operators
make an assessment of the needs of the system as a statistical whole
rather than considering the needs of each individual plant. This
leads to a treatment of wind output that is different than if it
were the only generating source available.

"Capacity value of wind

"Due to the variability of wind power, its capacity value is more
limited, as it will not be possible to displace conventional
generation capacity on a ‘megawatt for megawatt’ basis. The capacity
value decreases as more wind is installed on the system; at low
penetrations it has been put at roughly equal to the capacity factor
for wind (30-35%), but at higher penetrations the value decreases.
This is because with low penetrations wind output is hardly noticed
on the system, but when this increases, the variability of wind
becomes more noticeable and its ability to provide firm capacity is
reduced. National Grid Company have stated that 8,000 MW of wind
capacity would displace 3,000 MW of conventional plant, with 25,000
MW displacing the need for 5,000 MW. This means that wind power has
a capacity value of around 35% at penetrations of around 6%,
declining to around 20% at penetrations of 20%. These figures, along
with other corroborating evidence, were accepted by the House of
Lords Science & Technology Select Committee in their 2004 report
into renewable energy.

"It is worth noting that the capacity value of wind is higher in the
winter than in the summer, in line with seasonal changes in the
capacity factor. This means there is a correlation between the
capacity value and times of peak demand.

"Lower capacity values have been reported in other countries. For
example, a recent report by E.on Netz, one of Germany’s network
operators, with 44% of that country’s wind capacity, quotes an
average yearly capacity factor of just over 15%. However the UK’s
greater resource means that capacity factors and the associated
capacity values tend to be higher than most other European countries
and comparisons can therefore be difficult. In addition, the
integrated nature of the GB electricity grid, differing trading
rules (eg. gate closure times), and its wide geographical
distribution, separates it from some of the other problems faced in
Germany."



--
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 Fri, 18 Nov 2005 12:22:05 +0000 someone who may be Matt
wrote this:-

Those figures are just so ridiculous to be even considered.

Ah, proof by assertion.

(see the
current weather conditions in the UK and then go for a drive to
observe the distinct lack of rotation of wind turbines)

The fact that some wind turbines are not generating does not mean
that they all are not, for the reasons given in the Oxford report I
referred to.

"National Grid Company has confirmed that accommodating significant
amounts of wind capacity on the electricity system is unlikely to
pose any major operational challenges. Indeed there’s no technical
limit on the amount of wind that can be absorbed by the system – the
issue is simply one of cost.

That I do know to be incorrect,

Ah, proof by assertion again.

the people that do know the real facts
have in recent years been marginalised to stop them kicking up a fuss

Ah, it's all a conspiracy.

Even with a fully
interconnected system the drawbacks of significant wind generation are
being felt in at least three European countries. If anything they are
now retreating from their previously declared intentions.

Ah, the E.oN Netz study.

From the full SDC report:

"A critique of the E.oN Netz study

"A recent report from the German network operator E.on Netz, ‘Wind
Year 2003 – an overview’, appears to suggest that capacity values
are much lower, and additional balancing costs much higher, than the
figures quoted above. The report also highlights a low energy
productivity of German wind. It claims that the utility needs
reserve capacities amounting to 50-60% of the installed wind power
capacity, and that the extra balancing costs (for 6% wind) were
about €12/MWh of wind – over six times the estimates of Figure 6. On
closer inspection, there appear to be several reasons why the
numbers are quite different from the ‘consensus’ data discussed
above.

"Firstly, low wind speeds in Germany mean that the system operators
will experience more fluctuations in wind output than in windier
regions. To illustrate this point, assume that the average capacity
factor across Germany is 15% and the corresponding capacity factor
in Britain is close to its long-term average of about 30%. To
generate 8.5 TWh of wind in Germany requires 6250 MW of wind plant,
whereas only half that amount of plant would be required in Britain.
The power swings from 6250 MW of German wind would therefore be
higher than from 3125 MW of wind in Britain.

"Secondly, it appears that some of the apparent difficulties the
utility has with wind are more to do with administrative procedures
and barriers; the network operators tend to operate independently,
so some of the benefits of an integrated network are lost.

"Thirdly, plant commitments are made several hours ahead, and the
extent to which schedules are revised nearer to ‘real time’ is not
clear. The concept of a ‘one hour gate closure’, as in Great
Britain, or revising a schedule up to one hour before production,
appears not to be used.

"It may also be noted that the report does not discuss the
all-important question of the interaction between variations in
consumer demand and variations in wind output."

Look at the current weather pattern across the UK. A high pressure
area such as is currently being encountered is rather common in
winter. The wind speeds at the moment (5-6 mph across much of the UK
as reported by the met office)

Answered by the Oxford report I referred to earlier, which looked at
the records of hourly average wind speed over a long period.

Nukes are the ONLY way forward.

Ah, proof by 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 Fri, 18 Nov 2005 10:42:48 +0000 (UTC) someone who may be
(Rob Summers) wrote this:-

What it doesn't say is how much land will be required by
these windmills to generate sufficient power to make the prospect of
wind-power actually feasible.

Let's start off with the number of wind turbines.

http://www.bwea.com/energy/myths.html

"Myth: Tens of thousands of wind turbines will be cluttering the
British countryside

"Fact: Government legislation requires that by 2010, 10% of
electricity supply must come from renewable sources. Wind power is
currently the most cost effective renewable energy technology in a
position to help do that. Around 3,500 additional modern wind
turbines are all that would be needed to deliver 8% of the UK's
electricity by 2010, roughly 2,000 onshore and 1,500 offshore."

Then there is the question of how much land they will occupy, which
has been answered by someone else.

The authors of the report neatly sidestep the issue.

No, it isn't an issue.

You may be imagining a "power station", with a fence round it and so
on. http://www.bwea.com/media/photo/res/...osstractor.jpg
shows the reality.

http://www.bwea.com/media/photo/nwp/rgb/novar2.jpg shows several
turbines in a wind farm.


--
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

"Matt" wrote in message
...
On Fri, 18 Nov 2005 09:03:11 +0000, David Hansen
wrote:

On Thu, 17 Nov 2005 23:36:23 +0000 someone who may be Matt
wrote this:-

On the myth of wild fluctuations in wind output it has this to say:

"The most likely change in power output from a diversified wind
power system from one hour to the next is less than plus or minus
2.5% of the total installed wind power capacity. Larger changes from
one hour to the next do occur - a change in hourly output equal to
around plus or minus 20% of the installed wind power capacity is
likely to happen about once per year."

Those figures are just so ridiculous to be even considered. (see the
current weather conditions in the UK and then go for a drive to
observe the distinct lack of rotation of wind turbines)


The turbine I am admiring out of my window right now appears to be
significantly under-delivering in the rotation department. It has been
stationary all day. Even yesterday it was only achieving about half its
minimum speed...

OK, it's just a sample size of one, but it does mean a 100% outage of
commercial wind energy in the south east of England...

Andy.

On Fri, 18 Nov 2005 12:22:05 +0000 someone who may be Matt
wrote this:-

Look at the current weather pattern across the UK. A high pressure
area such as is currently being encountered is rather common in
winter.

In my earlier reply I forgot to add that Annex B of the SDC report I
referred to contains a concise statement on the subject.

'Winter anticyclones

'These, it is alleged, frequently becalm the whole country and cause
problems for the system operator, due to the absence of any wind
power, especially at periods of peak demand. The capacity credit, it
is argued, is therefore zero. However, the Environmental Change
Institute at the University of Oxford was quite clear when appearing
before a House of Lords Select Committee:

'"We have looked at that [stationary anticyclones in the middle of
winter over the British Isles] occurring in the wind data and the
wind data does not show it."'



--
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 Fri, 18 Nov 2005 14:35:54 +0000, David Hansen
wrote:

On Fri, 18 Nov 2005 12:22:05 +0000 someone who may be Matt
wrote this:-

Look at the current weather pattern across the UK. A high pressure
area such as is currently being encountered is rather common in
winter.

In my earlier reply I forgot to add that Annex B of the SDC report I
referred to contains a concise statement on the subject.

'Winter anticyclones

'These, it is alleged, frequently becalm the whole country and cause
problems for the system operator, due to the absence of any wind
power, especially at periods of peak demand. The capacity credit, it
is argued, is therefore zero. However, the Environmental Change
Institute at the University of Oxford was quite clear when appearing
before a House of Lords Select Committee:

'"We have looked at that [stationary anticyclones in the middle of
winter over the British Isles] occurring in the wind data and the
wind data does not show it."'

Lies, damn lies, and a distinct lack of hot (or cold) air.

How come the tabloids haven't got "PANIC FREAK WEATHER CONDITIONS
STRIKE THE UK" on the front page then? Simply these conditions *do*
happen, frequently.

About 15 miles away I can observe about two dozen of them right now
clustered in one of the highest wind installations in the country -
all of them are sat stationery, just as they have been since 6am this
morning. I passed another half dozen yesterday again sat doing
nothing due to a lack of wind.

The numerous jet trails are just sat in the sky taking about two hours
to dissipate. There is no wind, its bloody cold and the volts are
dipping. These windmills are not much bloody use today are they?


--

Matt wrote:
On 17 Nov 2005 18:07:38 -0800, wrote:

Imho no lights will go out though, prices (and energy saving drives)
will take care of that.

As a "for instance" the electricity selling price (not the cost of
generation) just dropped straight through the floor around five years
ago. As a result a major power station (7% of the installed UK
capacity) went bankrupt and was repossessed by the bankers,
fortunately they had difficulty offloading it as scrap otherwise we
really could be in the ****. That same power station is now on the
market and in a bidding war attracting offers around GBP2bn. Until
there is a coherent national energy policy and stable market
conditions no investor (other than one who has been siphoning off IMF
funds) will contemplate entering the market.

You're posing half the story only. Basic capitalist concepts tell us
that if the power station were decommissioned and we reached the point
where supply were insufficient, electricity prices would rise until
investors would return to the market. IRL the moves are slow enough and
preditable enough that a major station being decommissioned then
another getting rebuilt would be pretty unlikely.


NT

The message
from David Hansen contains these words:

Never trust politicians statistics.

I don't.

Are you suggesting that the University of Oxford
Environmental Change Institute are politicians?

They could be and in any event even scientists are not always as
impartial as circumstances should demand.

snip

"Capacity value of wind

"Due to the variability of wind power, its capacity value is more
limited, as it will not be possible to displace conventional
generation capacity on a ‘megawatt for megawatt’ basis. The capacity
value decreases as more wind is installed on the system; at low
penetrations it has been put at roughly equal to the capacity factor
for wind (30-35%), but at higher penetrations the value decreases.
This is because with low penetrations wind output is hardly noticed
on the system, but when this increases, the variability of wind
becomes more noticeable and its ability to provide firm capacity is
reduced. National Grid Company have stated that 8,000 MW of wind
capacity would displace 3,000 MW of conventional plant, with 25,000
MW displacing the need for 5,000 MW. This means that wind power has
a capacity value of around 35% at penetrations of around 6%,
declining to around 20% at penetrations of 20%. These figures, along
with other corroborating evidence, were accepted by the House of
Lords Science & Technology Select Committee in their 2004 report
into renewable energy.

It seems to me that this argument is based on the average output. No
wind at all might be almost impossible but what about the presumably
near 50% of the time when the output is below average? Sometimes it will
be well below average.

--
Roger Chapman

David Hansen wrote:
On Fri, 18 Nov 2005 12:22:05 +0000 someone who may be Matt
wrote this:-


The fact that some wind turbines are not generating does not mean
that they all are not, for the reasons given in the Oxford report I
referred to.


I'll say yes to wind turbines when Tony Blair, John Prescott and the
others agree to have one right next door to their principle residence -
sorry, I forgot, Tony Blair prefers to freeload off Cliff Richard and
others