....which is here
I connected the two 12V batteries on the bottom shelf in series so that the system would run at 24V. For the test divert load, I'm using some cheap 3KW convector radiators from B&Q. Running at 24V, each of them should eat about 300W.
The three 5 ft wooden blades are mounted onto a 5mm thick aluminium disk, here it is with the central locating hole for each blade drilled. Each blade is actually mounted using five 10mm high tensile steel bolts, but the other 4 in each group hadn't been drilled when this pic was taken.
The whole lot was pushed up facing West on a couple of 4 inch fenceposts.
The first real "blow" gave me a small problem in that the prop really needs to have quite a bit of torque to start the thing turning and so it needs to have a large diameter, but bigger props rotate slower than smaller ones and it was only rarely getting up to about 250RPM which is where it reaches 24V and starts to charge the batteries. So I moved the batteries into parallel to bring the required voltage down to about 12V. That got me this:
....and I opened the champagne.
Future developments: Instead of a badly carved nine-foot 3-blader, perhaps I'll try a badly carved six foot 6-blader. Hopefully I'll get the torque I need with a smaller diameter which should turn faster. Maybe. Or maybe I'll just buy a set of properly-aerodynamic blades instead!
Also I'll get rid of the upper fencepost and use some scaffolding pole instead to push it up a bit higher, and also stick it on a swivel mount with a tail so it can turn to face the wind.
