Wind turbines - can be DIY made?

[Mary Fisher]

Graceful - another positive word. I always think theyt're elegant, I shall add 'graceful'.

Thanks, David.

Mary

[David Hansen]

On Fri, 6 Oct 2006 14:45:21 +0100 someone who may be Roger wrote this:-

Perhaps I have confused people by not referencing all the relevant reports. The report on wind patterns in the UK is

which the following is a summary:

There was not a single hour over the study period when wind speeds at every location were too low to generate any electricity.

Low wind speed conditions extending across 90% or more of the UK during winter occur around one hour in every five years.

At an individual site low wind speed conditions are experienced

15-20% of all hours.

The single windiest site experienced high wind conditions for less than 2% of all hours.

There has never been an occasion when the UK experienced high wind speeds at the same time.

The windiest hour in the study period affected around 43% of the UK and one would expect this to happen around one hour in every ten years.

not bothered to mention what is written at the bottom of that page, which is "Oliver Tickell is a freelance writer based in Oxford".

Should one wish to get one's information from the horse's mouth, rather than a freelance writer, then this is easy to do at

which can be reached by going to and following the departmental links.

Mr Tickell claims that, "In evidence he presented to the House of Lords Science and Technology Committee in 2003", yet the horse's mouth says this was presented in 2004.

As to the claim you quoted, this is a rewording of paragraph 26 of Mr Sinden's evidence to the House of Lords in 2004, available at

one can see from the whole of the evidence this is actually a comparison between placing all one's eggs in one basket and having a variety of sources. I suspect that selective quoting of this evidence is why Mr Sinden expended on it subsequently in his oral evidence and particularly the Supplementary Memorandum

[David Hansen]

On Fri, 6 Oct 2006 09:57:34 +0100 someone who may be Roger wrote this:-

The report entitled "The Costs and Impacts of Intermittency: An Assessment of the Evidence on the costs and impacts of Intermittent Generation on the British Electricity Network (2.77 MB)" is the report referenced at that link and it does not contain those words.

In another message you will see where those words do come from.

[David Hansen]

On Fri, 6 Oct 2006 17:59:51 +0100 someone who may be Roger wrote this:-

Several appeared on the server I use at one go, presumably a propagation problem. Unfortunately by then it was too late to respond properly and I have been busy with other things, including work, since then.

The basic work in this area was done by Oxford University

that does allow for low and high winds.

Electricity suppliers don't work on averages. If they did the lights would go out rather often.

Rather they work on statistical models, including forecasts of supply and demand, which are outlined in the UKERC report. So far you have yet to demonstrate a flaw in that report. "The Costs and Impacts of Intermittency: An assessment of the evidence on the costs and impacts of intermittent generation on the British electricity network" March 2006.

What in those two sentences is an exaggeration?

[David Hansen]

On Fri, 6 Oct 2006 14:43:14 +0100 someone who may be Roger wrote this:-

Is anybody proposing this, by which I assume you mean throwing away capacity which still has plenty of life left?

Ditto.

One needs to be very careful in separating out "backup" that would be provided no matter how the electricity is provided and any extra "backup" that is provided solely because of the use of intermittent generation.

Having done that one then needs to consider whether that "backup" is new, or existing plant that is either not run so often or is run at less output.

One also needs to understand the different forms of "backup" and their varying timescales. The report I have referenced before, "The Costs and Impacts of Intermittency: An assessment of the evidence on the costs and impacts of intermittent generation on the British electricity network", covers these in section 2 and is well worth a read for those who want to know more.

[David Hansen]

On Fri, 6 Oct 2006 20:32:46 +0100 someone who may be Guy King wrote this:-

300 minutes (5 hours) according to

[David Hansen]

On Tue, 10 Oct 2006 12:38:09 +0100 someone who may be "Mary Fisher" wrote this:-

Another word is relaxing (and the related calming).

I suspect that some who have never seen such a machine imagine the blades hurtling round like an aeroplane propeller. In reality they rotate relatively slowly (which is one reason why they are not a great danger to birds) and people have reported watching them as being rather relaxing.

[David Hansen]

On Tue, 10 Oct 2006 08:51:29 +0100 someone who may be Roger wrote this:-

Well, I can see it above what I'm typing now. Your point is?

The generators are generating into the grid and electricity is being taken out elsewhere. Electricity is not a flow of electrons, particularly AC where the electrons hardly move but are simply waggled back and forwards a bit.

[David Hansen]

On Tue, 10 Oct 2006 10:05:47 GMT someone who may be "Brian Sharrock" wrote this:-

Nice try, but incorrect. Life-cycle carbon dioxide emissions are a great concern to people who think like me. However, those emissions (in running and upgrading, as well as building the place) are outweighed by the reductions in carbon dioxide the place achieves.

One may ask about decommissioning, but hydro schemes are seldom decommissioned. Indeed the pumped storage scheme at Foyers was an upgrade to the original scheme which was installed for aluminium production.

Ah, aluminium production. Certain aluminium products are marketed as being produced using hydro electricity. I suspect the number of products marketed this way will increase as more people understand the issues.

[Mary Fisher]

YES! Keep 'em coming :-)

I find them relaxing, but almost hypnotic.

I can't understand the damage to birds reports.

Cue for lots more flack :-)

MAry

[The Natural Philosopher]

No, he has a valid point. Net AC current flow through the grid is a function of the position of generation and load.

However line losses are the least worry...the transformers probably lose more.

BUT the fact remains that small scale generation is in itself inherently less efficient, in almost every way. The costs - particularly labour and energy costs - of lots of little turbines - do not scale linearly. The wind speeds closer to the ground are particularly inclined to be less, and fluctuate more.

In short, a turbine in your back garden is likely to be a carbon negative investment.

[Owain]

You could add "poised" and "dignified" if you had a thesaurus.

Owain

[Mary Fisher]

It won't surprise you to know that I have a Thesaurus - a very well thumbed

1982 one - which is next to the computer. It's only consulted when I'm writing an article, not for self expression.

Mary

[The Natural Philosopher]

You add poised and dignoified if you are taking the right DRUGS, but to me they just look angular spiky and man made against a more or less semi-natural landscape.

[Huge]

FWIW, I think they're lovely.

And *much* nicer than a conventional power station.

[Roger]

The message from David Hansen contains these words:

That the population of Greater London is roughly double that of Scotland.

Per Wikipedia, estimates for 2005

7,517,700 and 5,094,800

[Roger]

The message from David Hansen contains these words:

No current, no power.

[Roger]

The message from David Hansen contains these words:

The submission doesn't actually say when it was submitted but even if the year was wrongly quoted the words quoted are accurate.

selective quoting is your own. When I originally quoted the item above I went on to say:

"Sinden goes on to say that the standby capacity could be reduced to 400 megawatts if the 10% was provided by 65% wind, 25% dCHP and 10% solar but no mention is made of what would be the case if wind was left out of the equation not what the installed wind capacity would have to be in order to provide its minor share in reducing the standby capacity."

[Roger]

The message from David Hansen contains these words:

What is average but a statistic.

"The second implication is that 'system margin' as defined in Section

2.3.2, becomes less meaningful when intermittent generation is introduced onto a system. The difference between installed capacity and expected peak demand is no longer a good indicator of how reliable supplies are likely to be. Intermittent generators will be generating at full capacity for only a small percentage of the time, and only at 30% or less of their capacity (assuming a 30% capacity factor) for half the time, and at 15% for a quarter of the time."

[Roger]

The message from David Hansen contains these words:

So the documented deaths of a Red Kite in Wales, four White Tailed Eagles in Norway and thousands of birds in California is relaxing is it?