Lets start here

not that you would get anywhere if you did start from here, mind you.

My ancestor, homo meandertalensis!

THE PROJECT

I have a goldfish pond. Its continued health requires water circulation via a pump. Currently this is via a 12v dc electric pump consuming approx 40w of juice.

Its actually a bilge pump, as I didnt want to pay the ridiculous amounts being asked for purpose-designed jobbies that would deliver the required 1m head (to a waterfall)

Now 'er-indoors resents any power at all being wasted on such frivolous pursuits when it could be powering endless reruns of  game shows. Solar power is an obvious answer, but those panels arent cheap and home construction a bit beyond me. Wind power? well thats another matter!

CHOOSE YOUR WEAPON

The expert opinion is unanimous - stick a HAWT 100 feet or so in the air, and I'd have enough juice left over to power my computers (given the reliability of the local power, this is tempting)

HOWEVER the cost of safely mounting anything that high, and attendant visual pollution, rule that out.

I did consider a lower level HAWT, driving a purely mechanical pump in the same way the old american windmills used to - even got the thing half built. more on that another time, perhaps.

But theres something about the simplicity of VAWTs that appeals to me, especially considering we're on the side of a hill and the wind currents are all over the place. That sounds like VAWT country to me.

The SAVONIUS is an obvious choice, particularly if I stick with a mechanically driven pump (an alternator driving the existing electric pump would be a more flexible option - again, maybe later down the track)

but its a bit basic looking - the idea of the turbine having a a decorative sculptural aspect appeals, and there are plenty of elegant VAWT designs - such as the Ropatec, ....

And then theres the Savonius derivatives, Sandia, Benesh, etc

which to choose??!!   more on that soon.