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Mistress Rose

Joined: 21 Jul 2011
Posts: 15987

Posted: Mon Dec 28, 15 10:01 am Post subject:
Looks interesting, and if it can cope with turbulence it may take wind generated power forward a long way.

RichardW

Joined: 24 Aug 2006
Posts: 8443
Location: Llyn Peninsular North Wales

Posted: Mon Dec 28, 15 2:22 pm Post subject:
Remember the roof mounted turbine that B&Q were selling? They too promised to work on a roof in an urban area. Ended up using more energy than they made.

crofter

Joined: 11 Feb 2007
Posts: 2252

Posted: Mon Dec 28, 15 4:40 pm Post subject:
It is difficult to judge the scale of the photo, but would be interesting to know what size they are. 1.5kw is a useful contribution.

Nick

Joined: 02 Nov 2004
Posts: 34535
Location: Hereford

Posted: Mon Dec 28, 15 4:47 pm Post subject:
1.5m diameter. https://dearchimedes.com/pdf/PP_022_final.pdf data comes from this poster. The original link is eighteen months old. I assume they work, or don't, by now.

crofter

Joined: 11 Feb 2007
Posts: 2252

Posted: Mon Dec 28, 15 5:47 pm Post subject:

Thanks Nick.

From that same link

Quote:

1.Under 2 m/s condition, even though the generating electric power may be not so sufficient, this Archimedes
spiral wind turbine can produce the electric power

It would be useful to have a figure for the "not so sufficient" power.

found this:

Quote:

at 15 m/s results in 1500W
costs about 3500 euros

15m/s is force 7 (near gale)

Nick

Joined: 02 Nov 2004
Posts: 34535
Location: Hereford

Posted: Mon Dec 28, 15 6:20 pm Post subject:
If you track back to the home page, there's a ton of links. Might be stuff in there. Clearly, it's manufacturer data which, while often accurate, is almost always an incomplete, biased picture. However, it's there.

Treacodactyl
Downsizer Moderator

Joined: 28 Oct 2004
Posts: 25795
Location: Jumping on the bandwagon of opportunism

Posted: Mon Dec 28, 15 6:29 pm Post subject:

Nick wrote:

If you track back to the home page, there's a ton of links. Might be stuff in there. Clearly, it's manufacturer data which, while often accurate, is almost always an incomplete, biased picture. However, it's there.

There's a rather skeptical blog post about the claims. I had a bit of a google when HL first posted up the link but couldn't find out much meaningful info apart from the various articles from 2014 that seem to refer to the same press release.

The link in HL's post seems to contains a bit of 'spin', but I like the idea and all the small wind turbines I've seen have been rather noisy and not having something looking like a common wind turbine would be useful.

RichardW

Joined: 24 Aug 2006
Posts: 8443
Location: Llyn Peninsular North Wales

Posted: Mon Dec 28, 15 10:18 pm Post subject:

crofter wrote:

It is difficult to judge the scale of the photo, but would be interesting to know what size they are. 1.5kw is a useful contribution.

A normal turbine would need to be about 3 to 4m across.

You can only extract X% of the energy out of the wind or the air flow will stall. Then you have to take into account the Betz limit which reduces further the amount converted to elec.

crofter

Joined: 11 Feb 2007
Posts: 2252

Posted: Mon Dec 28, 15 11:51 pm Post subject:
They claim 80% of Betz' limit on the original link

dpack

Joined: 02 Jul 2005
Posts: 46238
Location: yes

Posted: Tue Dec 29, 15 1:26 am Post subject:
i wonder if a wet version would work in moving water

Hairyloon

Joined: 20 Nov 2008
Posts: 15425
Location: Today I are mostly being in Yorkshire.

Posted: Tue Dec 29, 15 9:28 am Post subject:

crofter wrote:

Quote:

1.Under 2 m/s condition, even though the generating electric power may be not so sufficient, this Archimedes
spiral wind turbine can produce the electric power

It would be useful to have a figure for the "not so sufficient" power.

I had read that to be badly translated.

crofter

Joined: 11 Feb 2007
Posts: 2252

Posted: Tue Dec 29, 15 11:12 am Post subject:

Hairyloon wrote:

crofter wrote:

Quote:

1.Under 2 m/s condition, even though the generating electric power may be not so sufficient, this Archimedes
spiral wind turbine can produce the electric power

It would be useful to have a figure for the "not so sufficient" power.

I had read that to be badly translated.

I suppose it can generate *some* power at low windspeeds because it is more efficient than a conventional propeller type turbine. From the graph on the link which Nick posted, for March 2nd 2014, average wind velocity for the day was 2.74m/s & average power 58Wh so "not so sufficient" seems a good enough translation to me!

RichardW

Joined: 24 Aug 2006
Posts: 8443
Location: Llyn Peninsular North Wales

Posted: Tue Dec 29, 15 4:46 pm Post subject:

crofter wrote:

They claim 80% of Betz' limit on the original link

Even the biggest ones struggle to get to 80% of Betz limit.

RichardW

Joined: 24 Aug 2006
Posts: 8443
Location: Llyn Peninsular North Wales

Posted: Tue Dec 29, 15 4:52 pm Post subject:

crofter wrote:

From the graph on the link which Nick posted, for March 2nd 2014, average wind velocity for the day was 2.74m/s & average power 58Wh so "not so sufficient" seems a good enough translation to me!

Do you mean 58Wh total generation or that it averaged 58watts for each of the 24 hours it was metered? IE 1.392kWh or 1392Wh.

If the former then its controller prob used more than that over the 24 hours.

If the latter then that is a good production for a 2.74m/s wind speed. Most dont make any power at that speed.

Thats the problem with averages. There could have been no wind all day apart from one hour that pushed the turbine to the limit of its production.

dpack

Joined: 02 Jul 2005
Posts: 46238
Location: yes

Posted: Thu Dec 31, 15 7:49 pm Post subject:
a bit of an aside but a waterwheel of an appropriate sort and some gears and tings are very reliable

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