B&Q Wind Turbines (Merged Thread)

raymond

Hmmm I think I have figured it out now.

Windave and B&Q are being funded by labour to sell these things so that when they sell enough there will be a "wind" tax.

Think I'm joking ... tell me that in 10 years time ............

Skiduck

There is a website that will give you your local vaerage wind speed in m/s - I will rack my brains and try and remember it.

ooro

I think its a great innovation. Doubt I'll get one but the more people buy them the cheaper they will get. I saw a DVD player for under £20 quid today - and I remember thinking £100 was a good price just a few years back. As soon as the planning rules do change and you can put them up without too much fuss they will take off.

Thats what I think anyway...

Would love to hear from anyone who gets one!

O

Skiduck

wind speed date here:

http://www.dti.gov.uk/energy/sources/renewables/renewables-explained/wind-energy/page27326.html

kittiwoz

raymond wrote:

If you are thinkin about one of these then do some very very careful study first. The glossy leaflet and dvd presentation look great and its all very enticing, but if you look deeper you will find that the rated 1kW output is at 12.5m/s .... looks ok ... but there is a simple reason that they use m/s and not mph ........ 12.5m/s is almost 28mph which is one helluva strong breeze to say the least.

To be fair the reason they use m/s and not mph is that m/s is SI units. Those are standard engineering units and make calculating the Reynolds number a hell of a lot easier. No one uses mph in engineering anymore except the Americans and they still give pressure in lbs per sq inch. Use of imperial measurements transforms what should be elegant, explanatory, physical equations into messy equations full of imperical constants (frig factors).

There is also a good reason it is rated at 12.5m/s. Wind speed is variable, sometimes it is lower than average, sometimes it is higher. If a turbine were to reach its maximum capacity at average wind speed it would be wasting all the extra energy in the wind when the wind speed is high. Also I have noticed some people seem to think you can calculate the output over the year by assuming the wind speed is constant at the average. I should point out that this is incorrect. Kinetic energy is 1/2*m*V^2, hence the energy content of the wind is proportional not to wind speed but to its square and since power is rate of delivery of energy it is proportional to the cube of wind speed. Now you see why it is so important the wind turbines are able to take advantage of the higher energy content of high speed winds. It also means that to calculate the energy output over a year you would need to weight appropriately for high wind speeds. Multiplying the power supplied at the mean wind speed by the number of hours in a year would render a value in kWh that is entirely meaningless. Imagine three cubes of side, 1, 2 and 3 cm. Saying the average power produced by a turbine is the power produced at mean windspeed is like saying the average volume of the three cubes is 8cm^3 when in fact it is 12cm^3. Anyone interested in wind power should check out this guide from the Danish Wind Industry Association which is well written and provides quite comprehensive solid technical information.

Also to say that 12.5m/s is a "helluva strong breeze to say the least" is slightly misleading in that it falls bang in the middle of force 6 (strong breeze) on the Beaufort scale and is described thusly:

Large branches move. Whistling in phone wires. Difficult to use umbrellas.

Without recomending domestic wind turbines I mean only to point out that the cut in, cut out and rated speeds are quite appropriate. It is true that for some people living in very built up areas they will often not get enough wind a few metres above roof level to turn the blades but his means that their house is an inappropriate site for a wind turbine. It does not imply that the turbine should have a lower cut in speed or reach maximum power at a lower speed since at low wind speed the wind does not contain enough energy to be economically extractable. For most people living out of cities and large towns one of these turbines should be within its appropriate operating range. That is neither to say the conditions will be optimum, nor that it is necessarily economicaly advisable to buy one.

raymond wrote:

the amount of energy required to manufacture/install/run/recycle these windmills will probably be much higher than any energy they produce.

I can not comment on the Windsave device but am aware that the Swift turbine from Renewable Devices has been engineered to use the optimum amount of recycled materials and is designed to be carbon-neutral over its intended lifecycle.

matt_outandabout

My company is about to start sales (by Christmas) of similar rated turbines, ready for DIY installation, with batteries, inverter, diverter etc...for about £800...

Suddenly the payback gets financially as well as environmentally worth it

Matt

Sustainable Building Supplies

Ken-Dodds-Hairy-Knodule

matt_outandabout wrote:

My company is about to start sales (by Christmas) of similar rated turbines, ready for DIY installation, with batteries, inverter, diverter etc...for about £800...

Suddenly the payback gets financially as well as environmentally worth it

It's been worth it for a while - I know people who have them mounted on their van/trailer and hooked upto a leisure battery.

There are people who run (audio) rigs purely from solar and turbine and they can keep people dancing all weekend from just the panels on top of the van and a couple of small turbines..

The problem is the mainstream have been charging stupid money for the same things hippies/ravers have been doing cheapy for years.

Well done for bringing costs down to middle-england =]

bltchef

hi were i live i have 3 wind turbines so would it be a good idea for me to have my own wind turbine ?

harrisss

I'd love to have a wind turbine, but since they have only just gone into B&Q, I think I'll wait until the market saturates and competition brings down the price. Also, I believe blanket planning permission is on its way for most micro generated measures. I think its great that B+Q have started selling turbines, but for me, its not time yet.

Also, for real moneysaving benefits I believe you would be better off with a 6kwh grid connected turbine. Much more expensive (at about £18,000), but over its 20-25 year life span would certainly more than pay for itself. Also, by opting for a larger model you can maximise the amount of government grant available (I believe this is currently up to a maximum of £5000!)

niccy

I live on an Orkney Island (lots of lovely wind) and would dearly love a wind turbine BUT selecting the right one is giving me loads of grief.I liked the Swift but installation cost is to much in relation to cost of turbine. I am now thinking i will need to spend more so we can be self sufficant but that means a turbine which would power TWO houses