Thread: Hawts and Vawts
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Old 09-09-10, 05:00 AM   #3
Big Al
Big Al
Join Date: Jul 2010
Location: Scotland
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Patrick , many thanks your response and ref to Lenz. With all due respects to Lenz this looks to be a drag turbine and a "science fair project " 63 Watts indeed !! If I ever get round to it (too many projects !!) I would build a helix bladed lift Vawt and would n't think it worth the effort unless I could get 2-5 KWhr a day.
This might sound pie in the sky but I have the metal working machines to build this and a lucky bonus in that I've just completed a tree house for the grandkids with a lookout tower extending to 10 metres above ground level. Climbing to the top of the lookout tower I noted I have nothing between the top of the tower and the Gargunnock hills 5 miles away to the south west which is where the prevailing wind comes from in Scotland.
I don't dispute your and Bob McG's point hawts win but the point is , is it better to have a reasonably quiet and attractive vawt producing say 200W @ 6 m/s wind speed or an ugly, potentially noisy and more dangerous (more RPM ) Hawt producing say 600W at 6m/s but which has to shut down as soon as the wind reaches real power producing speeds? I don't know and am attempting to find out just what the gap between Helically bladed Vawts and Hawts is ; given the points on blade strength and potential operation in higher wind speeds for Vawts (lower TSR for a given wind speed plus extra bearings and better blade support I made in my post. Rgds Big Al.
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