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Bernie66
Joined: 14 Jan 2005
Posts: 13967
Location: Eastoft
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nathanbriggs
Joined: 23 Mar 2005
Posts: 35
Location: Chester
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MarkS
Joined: 01 Aug 2006
Posts: 2626
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dougal
Joined: 15 Jan 2005
Posts: 7184
Location: South Kent
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Jonnyboy
Joined: 29 Oct 2004
Posts: 23956
Location: under some rain.
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james_so
Joined: 10 May 2006
Posts: 1264
Location: Torbay, S. Devon
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dougal
Joined: 15 Jan 2005
Posts: 7184
Location: South Kent
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 Posted: Fri Oct 20, 06 7:27 pm Post subject: |
 
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| Jonnyboy wrote: |
So, the only thing most people need to know seems to be:
1. Will it vibrate my walls down?
2. Is there ever going to be a ROI on the capital investment
3. How much will it save per year in C02?
4. How much will it save per year off my bill? |
The problem lies with the answers to those questions.
Are the answers given by Windsave sales & marketing factually justified, or are they just BS?
How much it vibrates, how noisy it is, how long it might last and how much energy it actually generates (and hence saves, pays back etc) *cannot* realistically be quantified accurately, in advance, because they are very, very, very site-specific.
They all depend on how fast and how turbulent the wind is at your site.
And then how efficient the Windsave really is at trapping the available energy.
The only way one can *prove* for certain whether the salesman's claims regarding your site are true or false is to give the salesman loads of dosh.
Are Windsave offering *any* sort of money-back guarantee if it fails to live up to their salesmen's claims?
Is B&Q?
Although far short of *proof*, it has been consistently pointed out by damn nigh everyone that knows anything about wind turbines that Windsave's marketing/performance claims do seem to betray minds uncluttered by realism or technical understanding.
Nathan himself has pointed out that the "20 millisecond response to gusts" claim is nonsense based on misunderstanding.
Regarding the insurance point raised above, it would not be just the concern about building insurance, but having Public Liability insurance as well might be prudent...
This site has some cautionary tales...
https://www.oceansolar.com/rejwintur1.html
IMHO required reading for anyone contemplating such a purchase. |
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RichardW
Joined: 24 Aug 2006
Posts: 8443
Location: Llyn Peninsular North Wales
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dougal
Joined: 15 Jan 2005
Posts: 7184
Location: South Kent
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| Posted: Fri Oct 20, 06 8:54 pm Post subject: |
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| Justme wrote: |
| Could the shape of the house actualy increase wind speed as it flows over so helping the turbine? This is how planes get lift by using the speed increase of the wind over a curved object? |
Its because houses are NOT shaped like aircraft wings that the flow over them is turbulent.
The ideal site, as demonstrated by many traditional windmills around the country, is on the top of a wide, low, smooth, rounded to all sides, unwooded hill - where the shape of the terrain does provide a little bit of benefit.
That ain't the case with houses.
Did you look at the Wind Shadow link I posted to another page on the site Nathan flagged up?
It shows how much energy is available, compared to the building not being there. Did you spot any values over 100? I didn't.
https://www.windpower.org/en/tour/wres/shade.htm
Notice that you have to go 3/4 of the obstacle's height directly above the obstacle, to get even the wind you would have had without the obstacle...
If you only ever follow one link posted, look at the oceansolar page linked above - and indeed explore the rest of their site.
Here it is again https://www.oceansolar.com/rejwintur1.html
| Quote: |
| If the turbine can respond to gusts (ok so not in 20 mil sec) surely a gusting turbulant site is not too much of a problem for a small turbine. |
Gusts and turbulence are bad news. The turbine tries to turn to face the gust, and swings out of alignment to where the wind is coming from. Rather than benefiting from the gust, its effectiveness can be actually reduced.
Oh, and there's mechanical (fatigue) loads, vibration and noise to consider too.
Remember Windsave aren't *guaranteeing* the thing for 10 years - they *claim* that 10 years is its *maximum* safe life - which can only be reduced by adverse site conditions. Like turbulence.
Do you think your insurance is going to cover you if you leave it up beyond 10 years? And have you or they factored in the cost of taking the thing down?
Visualise turbulence on the sea - rough and irregular waves.
Now think of *sailing* a boat through such waves .
Which would sail through such turbulence better - a small boat or a big one? |
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RichardW
Joined: 24 Aug 2006
Posts: 8443
Location: Llyn Peninsular North Wales
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nathanbriggs
Joined: 23 Mar 2005
Posts: 35
Location: Chester
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RichardW
Joined: 24 Aug 2006
Posts: 8443
Location: Llyn Peninsular North Wales
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Nick
Joined: 02 Nov 2004
Posts: 34535
Location: Hereford
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Jonnyboy
Joined: 29 Oct 2004
Posts: 23956
Location: under some rain.
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dougal
Joined: 15 Jan 2005
Posts: 7184
Location: South Kent
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