Ed Lenz Vertical Axis Wind Turbine - Revision history

Marcin: /* Kostas Latoufis Comments on Ed Lenz and Dan Connell Turbines */

2021-03-09T02:33:31Z

Kostas Latoufis Comments on Ed Lenz and Dan Connell Turbines

← Older revision		Revision as of 02:33, 9 March 2021
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	Connells to do that.		Connells to do that.

	Cheers,		Cheers,
	Kostas		Kostas

Marcin: /* Kostas Latoufis Comments on Ed Lenz and Dan Connell Turbines */

2021-03-09T02:33:21Z

Kostas Latoufis Comments on Ed Lenz and Dan Connell Turbines

Marcin: /* About */

2021-03-09T02:32:31Z

About

← Older revision		Revision as of 02:32, 9 March 2021
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	=About=		=About=
	~~See~~ https://www.thebackshed.com/Windmill/articles/Lenz2.asp		https://www.thebackshed.com/Windmill/articles/Lenz2.asp

			https://www.windstuffnow.com/main/vawt.htm - 52W with 12.5mph.

			Maysville MO is 17.5 average wind speed. 52*(17.5/12.5)^3 = 142W! Not bad. Supersize it with 3" shaft and we are in business. A few kw are readily available,most of the time.

	=Dan Connell=		=Dan Connell=

Marcin: /* Dan Connell */

2021-03-09T02:18:08Z

Dan Connell

← Older revision		Revision as of 02:18, 9 March 2021
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	=Dan Connell=		=Dan Connell=
	*		*See http://opensourcelowtech.org/wind_turbine.html

	=Kostas Latoufis Comments on Ed Lenz and Dan Connell Turbines=		=Kostas Latoufis Comments on Ed Lenz and Dan Connell Turbines=

Marcin: /* Kostas Latoufis Comments */

2021-03-09T02:17:59Z

Kostas Latoufis Comments

← Older revision		Revision as of 02:17, 9 March 2021
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	*		*

	=Kostas Latoufis Comments=		=Kostas Latoufis Comments on Ed Lenz and Dan Connell Turbines=
	Hi Marcin,		Hi Marcin,

Marcin: Created page with "=About= See https://www.thebackshed.com/Windmill/articles/Lenz2.asp =Dan Connell= * =Kostas Latoufis Comments= Hi Marcin, If one is going to self-build a VAWT then it sho..."

2021-03-09T02:17:12Z

Created page with "=About= See https://www.thebackshed.com/Windmill/articles/Lenz2.asp =Dan Connell= * =Kostas Latoufis Comments= Hi Marcin, If one is going to self-build a VAWT then it sho..."

New page

=About=
See https://www.thebackshed.com/Windmill/articles/Lenz2.asp

=Dan Connell=
*

=Kostas Latoufis Comments=
Hi Marcin,

If one is going to self-build a VAWT then it should be the Ed Lenz
design. It is the only one that has been around for long enough. And
looking at the wind tunnel tests the efficiency seems good.

Yet, wind tunnel tests can be pretty tricky and such efficiencies would
be expected from a Darrieus three bladed vertical axis rotor with
slender blades. I would prefer a power curve measurement which is more
easy to conduct and the result can be trusted.

The HAWT school of WT design has a lot to say about VAWT:
www.wind-works.org/cms/index.php?id=116

> Unloaded and not set high, but survived the two worst winters in
> Massachusetts history, apparently.

Unloaded tests are not indicative as the torque on the shaft is almost
zero so there are no stresses on the blades. The main problem with VAWT
is that they have forces acting on the blades in the horizontal
direction which causes fatigue and failures on the blades, but I do not
have evidence for this, it is one of the disadvantages I have heard of.

In addition the rotors in the links are quite small, they produce up to
100W, and I wander what would happen if these were scaled up to 1kW or
more.

Personally, I would want a 500W to 1kW design to be installed somewhere
for 2-3 years at least (preferably 5 in order to make sure all
maintenance issues will have occurred), and see a measured power curve.
This can be done anywhere and at a low cost. So I would encourage Dan
Connells to do that.

Cheers,
Kostas

← Older revision		Revision as of 02:33, 9 March 2021
Line 10:		Line 10:

	=Kostas Latoufis Comments on Ed Lenz and Dan Connell Turbines=		=Kostas Latoufis Comments on Ed Lenz and Dan Connell Turbines=
	Hi Marcin,		Hi Marcin,

	If one is going to self-build a VAWT then it should be the Ed Lenz		If one is going to self-build a VAWT then it should be the Ed Lenz
	design. It is the only one that has been around for long enough. And		design. It is the only one that has been around for long enough. And
	looking at the wind tunnel tests the efficiency seems good.		looking at the wind tunnel tests the efficiency seems good.

	Yet, wind tunnel tests can be pretty tricky and such efficiencies would		Yet, wind tunnel tests can be pretty tricky and such efficiencies would
	be expected from a Darrieus three bladed vertical axis rotor with		be expected from a Darrieus three bladed vertical axis rotor with
	slender blades. I would prefer a power curve measurement which is more		slender blades. I would prefer a power curve measurement which is more
	easy to conduct and the result can be trusted.		easy to conduct and the result can be trusted.

	The HAWT school of WT design has a lot to say about VAWT:		The HAWT school of WT design has a lot to say about VAWT:
	www.wind-works.org/cms/index.php?id=116		www.wind-works.org/cms/index.php?id=116

	> Unloaded and not set high, but survived the two worst winters in		> Unloaded and not set high, but survived the two worst winters in
	> Massachusetts history, apparently.		> Massachusetts history, apparently.

	Unloaded tests are not indicative as the torque on the shaft is almost		Unloaded tests are not indicative as the torque on the shaft is almost
	zero so there are no stresses on the blades. The main problem with VAWT		zero so there are no stresses on the blades. The main problem with VAWT
	is that they have forces acting on the blades in the horizontal		is that they have forces acting on the blades in the horizontal
	direction which causes fatigue and failures on the blades, but I do not		direction which causes fatigue and failures on the blades, but I do not
	have evidence for this, it is one of the disadvantages I have heard of.		have evidence for this, it is one of the disadvantages I have heard of.

	In addition the rotors in the links are quite small, they produce up to		In addition the rotors in the links are quite small, they produce up to
	100W, and I wander what would happen if these were scaled up to 1kW or		100W, and I wander what would happen if these were scaled up to 1kW or
	more.		more.

	Personally, I would want a 500W to 1kW design to be installed somewhere		Personally, I would want a 500W to 1kW design to be installed somewhere
	for 2-3 years at least (preferably 5 in order to make sure all		for 2-3 years at least (preferably 5 in order to make sure all
	maintenance issues will have occurred), and see a measured power curve.		maintenance issues will have occurred), and see a measured power curve.
	This can be done anywhere and at a low cost. So I would encourage Dan		This can be done anywhere and at a low cost. So I would encourage Dan
	Connells to do that.		Connells to do that.

	Cheers,		Cheers,
	Kostas		Kostas