vinny1275
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| posted on 11/1/07 at 09:08 AM |
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Wind turbines
OK, completely off-topic.....
I've been thinking about wind turbines for power generation (I have quite a long drive to work...)
People object to the big noisy clanky ones based on the fact that they're mahoosive, painted bright white, and make a noise when they turn.
Birds (the feathered variety) don't seem to like them much either....
I was wondering if making the turbines smaller, but adding some flow control to them so they turn faster would be feasible. (The concept I'm
thinking of is like the circular housing round a jetski prop) - forcing the air through a narrowing opening with a funnel will speed it up and turn
the turbine faster. This means it can be smaller, less noisy, and less intrusive for the same power output.
Problems I can think of are making it turn into the wind (a rudder-thing behind it?), and mounting it so that it can turn (a ring contact on the head,
or a shaft to transmit the torque down and run the generator at the end of the shaft?), and the thing getting blocked (possibly with bird's
nests...)
Anyone have any comments / suggestions? I'm not sure I'll be out in my garage this weekend building one, just something that's
keeping my brain ticking over at the moment.......
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ecosse
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| posted on 11/1/07 at 09:38 AM |
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I looked into this a while back and found this company http://www.provenenergy.co.uk/ who have developed rotor that adjusts itself
depending on the strength of the wind, they claim it will even work in a hurricane and still produce power!
Maybe not exactly what you were looking for but the site has a lot of info about wind power (check the literature and downloads section) so may be
worth a look.
Cheers
Alex
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tiffshaw
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| posted on 11/1/07 at 09:42 AM |
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The problem you have is that the air needs to be driven through the constriction otherwise a high pressure area forms in from of it and restricts
flow.
At uni we looked at making a similar device for crop spraying and the size of the duct required turned out to be about 90% of the wing lenth
Chris
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Howlor
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| posted on 11/1/07 at 09:47 AM |
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I personally am quite in favour of the wind turbines. I have to admit that I do not live next to one but whenever I have been close to them the noise
seems minimal lets say in comparison to living close to a motorway.
Lets face it, if you lived next to windy miller a few years back I reckon that would have been noisier but no one would complain if somebody wanted to
restore an old windmill. In fact I am sure they would get grants etc to help them!
I pass the two turbines on the A47 regular and think they are an absolutely fantastic sight.
By the way I can see your thinking with the ducting to accelerate the flow.
They are in final planning for building a wind farm near us but there is a local campaign group to stop this. What is refreshing though is that there
has developed an equally large campaign group of locals that are for them!
Steve
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macnab
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| posted on 11/1/07 at 09:55 AM |
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here's a good site I found a while ago.
my place is very very windy so I was going to get the 2kw one.
www.navitron.org.uk
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flak monkey
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| posted on 11/1/07 at 09:55 AM |
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We have loads of turbines around close to home. I think they look great and arent that noisy. I can appreciate some of the concerns, but many are just
NIMBYish. There are 2 that supply the power to a whole large villiage when they are turning, which is nearly every day, even when you think
there's not eough wind!
[Edited on 11/1/07 by flak monkey]
Sera
http://www.motosera.com
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macnab
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| posted on 11/1/07 at 10:07 AM |
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Yeah we have about 20 very large turbines between Aberdeen and Inverness, I love them but they are along side the road and are one hell off a
distraction when your driving.
There’s also suppose to be a large wind farm being built offshore from Aberdeen but I’m not sure it will go ahead. Pity.
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Kissy
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| posted on 11/1/07 at 10:31 AM |
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Generally I'm in favour of them - I intend to have one or two small ones when we eventually move to Skye - the issue that concerns me is this
planned (approved) Government development off the west Scotland coast on one the Isle of Lewis. This will be hundreds of 400ft high turbines. Not
surprisingly the few locals are a bit upset, mainly because the power is actually for the mainland - so they don't get any benefit, the service
roads will rip across what is currently stunning untouched scenery, and the fact that the most significant threat to eagles and other similar rare
birds is currently turbines.
Links:
http://news.bbc.co.uk/2/hi/uk_news/scotland/4557255.stm
" target="_blank">http://news.bbc.co.uk/2/hi/uk_news/scotland/4635897.stm
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BenB
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| posted on 11/1/07 at 10:36 AM |
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A vane on the back for direction control is traditional windmill type technology (love the wooden windmills on circular rails where the whole thing
rotates!!)....
The usual way of adjusting power for given speeds is variable angle props.. A little complicated with the gearboxes in the hub but they work....
Ducting to increase air flow would be okay unless you over did it. Then as mentioned you'd get high pressure in front of the blade causing
stagnation and no flow... Also you'd have to be careful about how fast the air went through it and what happened to the air exiting after the
blades.
The neighbours might be happy that there isn't a huge prop flying round next door but if your tubular duct resonates like a trumpet they might
not be too amused.... 
[Edited on 11/1/07 by BenB]
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bartonp
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| posted on 11/1/07 at 10:37 AM |
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quote:
Originally posted by vinny1275
OK, completely off-topic.....
I've been thinking about wind turbines for power generation (I have quite a long drive to work...)
People object to the big noisy clanky ones based on the fact that they're mahoosive, painted bright white, and make a noise when they turn.
Birds (the feathered variety) don't seem to like them much either....
I was wondering if making the turbines smaller, but adding some flow control to them so they turn faster would be feasible. (The concept I'm
thinking of is like the circular housing round a jetski prop) - forcing the air through a narrowing opening with a funnel will speed it up and turn
the turbine faster. This means it can be smaller, less noisy, and less intrusive for the same power output.
Problems I can think of are making it turn into the wind (a rudder-thing behind it?), and mounting it so that it can turn (a ring contact on the head,
or a shaft to transmit the torque down and run the generator at the end of the shaft?), and the thing getting blocked (possibly with bird's
nests...)
Anyone have any comments / suggestions? I'm not sure I'll be out in my garage this weekend building one, just something that's
keeping my brain ticking over at the moment.......
Can't you just use an alternator to charge the battery like eveyone else?
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Pete Jordan
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| posted on 11/1/07 at 11:00 AM |
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I was having a look on the web recently after seeing the turbines that B&Q are now doing. I found a company called Swift
http://www.renewabledevices.com/swift/ who do a turbine that they claim is nearly silent (there's a video of it running on their site
and its pretty quiet), something to do with joining the blade tips with a ring to reduce the blade tip "swish" as it rotates. It is
pretty expensive at the moment (£3,500 plus installation) but they are only just starting to supply them and intend to have the price down to about
£2,000-£2,500 in a year's time. I think a lot of the cost is not only the turbine itself but the electronics that allow it to connect to,
supply but not be driven by the domestic electrical system.
regards
Pete
[Edited on 11-1-07 by Pete Jordan]
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macnab
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| posted on 11/1/07 at 11:51 AM |
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been comparing the turbines sold a B&Q to those available on the web. B&Q's are roughly twice the price for comparable turbines...
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yorkshire-engines
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| posted on 11/1/07 at 12:15 PM |
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Wind turbines well here is my two penneth
i live on a farm in north yorks and as most of you know who has been here its remote we dont have mains electric up here but i do have a wind
turbine which cost me around £20k (less government refunds) to install
it generates approx 10 kw of free electric and powers 2 houses with 2 large garages with no problem the battery storage will last 48 hours with no
wind then we have a back up generator just in case and its gaurenteed 25 yrs maintenence free so im all for it
and its bloody windy here today so its also powering my central heating as well
im also looking at returning the excess power produced back to the electric board which i do at the moment they just pay me for the excess produced
but i could make them lay a cable to take the excess away funny old world isnt it they wouldnt lay a cable when i first asked them now i can make
them if i want
[Edited on 11/1/07 by yorkshire-engines]
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macnab
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| posted on 11/1/07 at 12:22 PM |
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Way to go
Although 20k sounds expensive. That's not all that much compared to connecting 2 houses to mains anyway, especially if you have to pay for the
transformer (as I had to )
Don't know I you have ever worked it out but how much would 25 years for 2 houses cost just for the electrically alone. I'm sure your
making a huge saving in the end.
Wish more people would have the same foresight.
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Ian Pearson
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| posted on 11/1/07 at 01:12 PM |
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Been looking at wind power for a while. The small B&Q types, (from what I've read), are not particularly practical, and take years to pay
back. Now looking at a turbine from Proven Energy, as the long term savings are much better. Looking at about £19000 less a £5000 grant. A lot of
money to shell out, but if you sell excess back to the grid, the long term savings are very good. Planning permission could be a problem but
we'll have to see!
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macnab
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| posted on 11/1/07 at 02:27 PM |
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I'd hope (yet to find out) that the local counsel would be lenient on planning permission for environmental things.
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Guinness
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| posted on 11/1/07 at 02:56 PM |
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Well, from my office I can see 10 wind turbines, 8 little ones on the pier and 2 massive ones out at sea. (I work in Blyth).
The two massive ones haven't turned a blade in nearly a year.
And today, the little ones are practically stopped, just spinning slowly. I guess it's too windy for them.
Mike
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MikeRJ
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| posted on 11/1/07 at 02:56 PM |
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quote:
Originally posted by yorkshire-engines
im also looking at returning the excess power produced back to the electric board which i do at the moment they just pay me for the excess produced
So they pay you for making excess power, but they don't have access to it? Strange old world as you say. How do they know how much excess you
have made?
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scotlad
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| posted on 11/1/07 at 03:00 PM |
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Selling excess back to the grid? you'll be lucky to get enough to juice to power your fridge, never mind a whole house.
Current windy weather aside, the last year and a half has been hopeless for wind generation with the biggest windfarm in britain generating hardly
anything (i used to be a wind turbine engineer there) so in my humble opinion, i'm afraid the b&q turbines and others similiar are a waste
of cash. The money's better spent on more loft/ wall insulation!
Anything over 25m/s wind speed for more than a few minutes and a large turbine will pitch its blades and sleep until the wind drops again whereupon it
will automatically yaw into the wind and start generating again.
[Edited on 11/1/07 by scotlad]
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smart51
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| posted on 11/1/07 at 03:34 PM |
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The 1.5kW turbine I looked at made 125W in typical wind conditions. That’s enough to power the things in your house that don’t switch off – central
heating timer, alarm clock, video on standby, fridge, burglar alarm etc. Any excess that is put into the grid is called overspill. The power
companies don’t want it. You can make them buy it but the standing charge for the tariff is more than the likely payment that you’ll get back. Just
be happy with the 30% or so less power from the grid that you have to buy.
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Ian Pearson
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| posted on 11/1/07 at 03:56 PM |
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From what I’ve read, the micro turbines are not worth it unless you live in a windy area, and your demand for electricity is low. Too much wind and
they shut down.
A 6KW turbine should provide in excess of 10MW per year, and that is based on an average wind speed of 5.1m/s. If connected to the grid, Powergen will
pay 8p per unit. It’s quite an outlay, but in the long term, offers good savings.
I’m no expert, and these are figures I’ve gleaned from various articles I’ve read recently.
The wind average for my area is 5.6m/s at roof top level, (DTI website) and rise with an increase in height, so a larger wind turbine should be a
practical proposition. Longevity and maintenance are something else to be considered though.
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rav
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| posted on 11/1/07 at 04:16 PM |
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One of the problems with wind turbines if my hazy recollection of lectures at uni is correct is tip speed.
The bigger the blades get and/or the faster it spins, the higher the tip speed. Even though the big turbines you see around appear turning quite
slowly and gracefully (IMO), the tips are capable of approaching the speed of sound I think. Can anyone confirm that - I might have imagined it??
So a turbine rotating at much higher rpm might have sound barrier problems?Dunno, just a thought.
This site has info recorded froma roof top in edinburgh, and relates theoretical windpeed to actual. Worth a read if you're thinking of
installing a small turbine - where its sited makes a big difference!!
http://www.scoraigwind.com/citywinds/index.htm
Micro Hydro is deffinitely a much better option if you're lucky enough to have a stream/river on your property with a reasonable head. Steady,
relaible power 24/7. Hydro power installs pay off very quickly, have a look at the small hydro turbines on the website mentioned before -
www.navitron.org.uk
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