50W Telescopic Vertical Axis Wind Turbine

http://www.maplin.co.uk/Module.aspx?ModuleNo=396269

What do you think of that? Wonder what the generator inside it is?...Mmmmm

[Gotwind Ben]

Looks very interesting Vic,
The right price also, I suspect they will sell very well, comparable to a solar panel of similar power - I see they are out of stock already, I want one..
From the enlarged image
http://www.maplin.co.uk/images/full/n91hx.jpg
It looks like steel cored alternator unit, a bit like a car alternator.

Good find.

[Gotwind Ben]

Darn it..

Thank you for your email i apologise for the delay in replying to you.

This item is due in stock on the 17th of August.

Er wait a mo, look at the rated windspeed. So that's £180 or so to get 50W, oh, but only on those occasions when you happen to experience a 30MPH wind?

Surely far more cost effective to paste a flexible PV to the motorhome's roof, and far less chance of some thieving fatherless deciding to liberate that.

[Gotwind Ben]

The blurb states
Effective with wind speed of 8 - 10m/s
thats 17.6 mph- 22.3 mph
Who nows what 'effective' relates to, rated output??



1 m/s is equivalent to:

= 3.6 km·h−1 (exactly)
≈ 3.2808 feet per second (approximately)
≈ 2.2369 miles per hour (approximately)
≈ 1.9438 knots (approximately)

Of course it is. What the devil made me forget that conversion?

Lack of red wine, perhaps....

Easily remedied.

<Hic>

Edited to add: "Effective" as in "Hey, it's turning at last"?

Hrmm, this is a ~2 square foot Savonius type VAWT with max rating of 12-16v and 4A suggesting ~48W, theoretically @ around 10m/s. If this is the case then the overall CP has to be at least 0.40, a figure I find difficult to believe. I would guess the actual CP is closer to 0.20 than 0.40, and that the 50W rating is simply the alternator max capacity. If we work with the idea that the CP is ~0.20 then the swept area leads us to an 8-10m/s wind delivering 12W-22W. @ ~$260.00 US, this brings us to $21.66/W to $11.81/W. In the more typical 5-7m/s winds we might hope to get 3W-8W. Of course if you are in a high wind area then 22W * 24 hours = 528Wh, it would take an 90W solar panel to produce the same 528Wh in 6 solar hours, so from this point-of-view it is a "bargain". Even at 8W * 24 hours, this is 192Wh, and a comparable PV panel would have to be at least 32W (again assuming 6 hours of insolation) to match it's output. I think a Lenz II design could improve on performance in the price category and be made to store in roughly the same space. If you take six Lenz II design "winglets"; removed from the turbine they would store nicely in a round tube. Snap two "winglets" together to make a single longer "winglet", and attach the "winglets" to the central hub with quick disconnects and you could easily assemble a VAWT with a swept area of 24 square feet (6 feet tall by 4 feet in diameter.) With an overall CP of 0.20, this should yield 32W @ 5m/s, 142W @ 8m/s and 270W @ 10m/s. In a medium volume production setting it is likely you could make money selling such a rig for $300-$500 US.

I will say it is good to see that someone is at least attempting to produce a commercially viable VAWT :-)

Fish

Fish - you should patent your idea :)

Agree with your comment about 50w possibly being the max output of the alternator.

Yes, but I would still observe that the crux is the high wind part of it all.

Perhaps I'm soft but personally, I don't wait for sustained high winds and then say "Great! Time to do a little camping at the beach and get everything including myself sandblasted". No, if I'm on holiday at the time, I look for a pub and hope the wind dies down a bit.

Yes it could charge a motorhome battery when one's not on holiday and the thing is parked, but (a) if it's in the garage then no it wouldn't , and (b) if it's outside then this spinning moving eyeball attraction would be an irresistible yobbo magnet.

That's what would happen in the UK at least, and the police would tell you it was your own fault for attracting the yobbos in the first place. I suppose in the States, Ghurd could shoot em off the roof with his magnetic guns!

That does look good!
Looks like you could stick it in a spare chimney and get away with no planning :mrgreen: :mrgreen: