Sorry - I'll have to jump on you for this one as well ferel air...
'A successful s-vawt? Define successful...'
Something that's reasonably cost effective over the course of time. To accomplish that it needs to produce reasonable power and be reasonably reliable.
'I think most of the people that build steel barrel vawts just set 'em up and let 'em be...never really updating their web pages or giving progress reports.'
That's because they're probably very dissapointed in the performance. They may have some merit if you're just wanting to pump a bit of water or grind coffee...
' Why would they?..it's up and doing it's job.'
Actually - it's probably slacking off rather badly on its job if it's an electric machine.
' Of course there's lots of other types and construction methods too but that seems to be the first vawt people come across or recognize.'
Yes.. because it seems so easy and barrels are a dime a dozen and there are a few people out there saying things like... if I were going to build a wind turbine I'd make a VAWT!
'What kind of report are you looking for?'
KWH per month or something... something better than pictures and a you tube video at any rate. (is this the sort of thing you had in mind?)
http://www.youtube.com/watch?v=RZJ7tWRQy4w
' As far as long-term reliability, that's in the design and build quality and hawts can suffer there too. If we're just looking at the numbers (or anecdotal evidence, anyway), hawts fail way more often than vawts.'
Actually - no... they don't. There are lots more HAWT failures only because 99 (guessing)% of wind turbines (and way more than that if you figure 'workable' wind turbines) are HAWT's.
'Numbers rarely tell the whole story though. :-)'
Wind power is all about numbers and I think they deserve at least some attention.
'Personally, I think it's easier to design and build a rugged all-weather s-vawt that you can leave unattended.'
Nice idea.. I wonder how you keep it under control in high winds? I'd probably worry about that after I actually figured out how to get real power from one though.
' Just use beefier materials all around - the basic concept and construction remains the same.'
It's not that simple.
' There's no furling system on an s-vawt that can fail'
Furling systems done right don't fail, they're very simple. You still need to come up with something though - on every VAWT that accomplishes the same task as a furling system. There is no 'easy' way to do that with a VAWT.
'and it will never throw a blade at lethal speeds.'
You don't think?
' That's not to say that you couldn't screw the design and/or build it poorly though...that's always a possibility...and an s-vawt failure could be lethal with a heavy enough rotor and tall enough pole. What are the chances though?'
The chances of failure seem fairly high to me - lethal... I guess that depends on where you stick it.
'I think I'm rambling now...like I said, I'm biased.'
Yes, I think you are and so am I. Let's look at things this way. Think about a home made 10' diameter wind turbine that's perhaps 20% efficient (I'm being conservative), sweeping about 80 square feet, and weighing about 100 pounds sitting on a decent tower which is getting it about twice the 'wind energy' as it would be if it were sitting on the ground. It spins quickly and therefor can have a fairly small direct drive alternator.
Then consider the large barrel S VAWT which might be 10% efficient (I'm being optimistic). To sweep the area I guess it'd have to be 5' wide and 16' tall. It only has half the efficiency so it needs to sweep twice the area. So 5' wide and 32' tall. I think if you're lucky, such a machine might compete with a 100 pound 10' diameter HAWT on a tower - although this monstosity is likely sitting on the ground and the very top is only 32' up so to be fair - you need something even larger. Doesn't seem very practical - and in 70mph winds it actually seems quite scary to me.
Look around at people who actually power their homes with wind and you won't notice any such machines. Not to say there are not VAWT designs that have some potential - but I don't believe there are any that can be as cost effective as a good HAWT (yet).