Home wind turbine - Page 1
Forum section: electronics / general

author: Simon
author_rank: Unknown
timestamp: December 14, 2019, 10:50:46 pm
content: So my roof is smothered in panels and i was wondering what small wind turbines cost these days..... not much if i beleive the amazon prices. But are these turbines any good? Has anyone got recommendations on a wind turbine?

author: Kleinstein
author_rank: Super Contributor
timestamp: December 14, 2019, 11:08:15 pm
content: There is a small market for small wind turbines, e.g. for use on boats. However these are often made for rather high winds and more seasonal use.There is an advantage of scale with wind turbines. The large ones are further up (especially way higher than the trees and houses) and thus get more and more steady wind. There is another problem with small size: there will be more turbulence as the Reynorld's number goes up and thus more noise (and less efficiency) with a small one than with a large one. So the conditions are not that great for a small turbine.It really depends on the local conditions how much wind to expect.

author: Simon
author_rank: Unknown
timestamp: December 14, 2019, 11:10:59 pm
content: I know it's not a great solution in small sizes but i want to tinker. I seem to have quite a bit of wind down the back of my house.

author: fourtytwo42
author_rank: Super Contributor
timestamp: December 15, 2019, 06:03:16 pm
content: Quote from: Simon on December 14, 2019, 11:10:59 pmHi Simon that's exactly what I thought a few years ago so I bought a 600W unit to play with and TBH it was fun and I was lucky enough to be able to sell it for more than I paid so free fun tooResults....Hmmmmm, lookup LAMINAR FLOW if you aint got it then your stuffed in broad terms! The problem is nearby obstructions (houses tree's etc) cause turbulent flow and that's an anethma to a turbine, it basically spends it's life hunting the wind direction and rarely powering up. I tried everything, rewinding the alternator, changing the blade angle but the only thing that made it better was height and I mean a lot! Now take a look at our glorious planning laws and you find you are not supposed to erect a turbine if when it comes crashing down (apparently they do this all the time) the blade tips would cross your boundary! If your lucky and live on a farm all well and good but for most of humanity our gardens aint big enough! I had mine about as far as I could get from the house (~10M)with a solid existing foundation (tall tree stump) and about 10M up but nowhere near good enoughSo to cut a long story short, another reason to go live in the wilderness xept as usual the other half doesn't see it the same way

author: Simon
author_rank: Unknown
timestamp: December 15, 2019, 06:08:57 pm
content: Well it would go on an outbuilding that sticks out from my house and my neighbours. So yes a bit of "a thing" for the air to slam into and then try to get over. I would of course have to keep it low.What about those vertical turbines? I no that they are not great in scaled up sizes but is it a case that on a small scale with wind that is a bit turbulent it could offset the disadvantages ?

author: fourtytwo42
author_rank: Super Contributor
timestamp: December 15, 2019, 06:19:16 pm
content: Quote from: Simon on December 15, 2019, 06:08:57 pmNot wishing to be a jona basically there is physics and salesmen/misinformation, I refer you to a recent callout here in the Dodgy tech section regarding wt claims and there's a lot of it about. Best readup yourself about stuff in reliable text books rather than listening to hearsay or people with golden tonguesBTW not a good idea mounting on a building, the vibration down the pole is quite a lot even on a 600W unit, I would have thought enough to loosen some brickwork and the sideload forces need accounting for as well.At least on a pole down the garden the worst it can do is entagle her indoors washing rather than tear the building down

author: Simon
author_rank: Unknown
timestamp: December 15, 2019, 06:23:35 pm
content: Hm yes, i might just give up on the idea. What I was more interested in is are these relatively cheap units reliable? You can get 600W for 200 quid now.

author: fourtytwo42
author_rank: Super Contributor
timestamp: December 15, 2019, 07:00:30 pm
content: Quote from: Simon on December 15, 2019, 06:23:35 pmWell I took mine down after about 18 months but nothing failed in or on the unit just that I could not get the right wind for it. If I had been successful maybe something would have lasted only a few years, my guess would be the yaw slip rings/brushes, as that was a sealed unit I never had it apart. The other possibility would be the front (and only) main bearing due to moisture ingress but it might be stainless, finally there is the plastic molding around that bearing, I have had that problem in a power drill before but fixable with plenty of epoxy. Of course if you buy electronics with it (charge controller etc) then that's a whole other story! Of course like all hobbies the main thing is have fun