I'm really determined to try a small VAWT myself to get some feel for how it works (so I can stop being so wet about it!) and I'll try a drag-type unit like that first since we have a plastic drink bottle about to become available! This one won't be forepower, but I'm eventually aiming for (say) a maximum of 30W peak @12V in a reasonable breeze, ie a little more than my laptop load to be able at best to power it and provide a little top-up.
Ben, aren't these drag-type VAWTs meant to be severely limited in maximum efficiency by how fast they can move? Isn't a lift type (even just aerofoils fitted onto existing blades such as yours) said to me potentially and actually much more effective?
From the figures I saw on a commercial site, your mill, if converted to lift, should be able to put out ~50W in a decentish wind at my entirely unskilled guess. For that same swept area what would you hope to get from a HAWT?
(Anyone got a link for wind speed and theoretical power allowing for Betz that I can use?)
Rgds
Damon
