The Wind is Free!

I don't quite follow exactly what the graphs are. Have you taken into account generator efficiency? Blade efficiency? etc? Intuitively it seems a bit close, i.e. the available power should be more above the output power.

40Ah in 24 hours = about 2amps continuous, which is about 25 watts Lets take a 1m radius blade, and work with max possible power. 10km/h = 2.7m/s max power 21Watts 15km/h = 4.2ms max power 82 Watts So wind speed is critical. Since you will lose power by gearing up with ...

I am confused by your post. Under "1.5m blades" I see only one graph
containing the 1.5m blade curves. The graph name is "AE 3.0m.jpg".
The graph title is "Aero Energy 3.0m". What am i missing?

Hi Aero. I am trying to plan a generator to match your 1.5m blades, so I need the power curves. I see under "1.5m blades" above you posted a graph, but the graph is title "1.9m". Do you have anything for the 1.5's? I understand its ...

OK,
This is what I came-up with sofar:

... It will end-up the same answer, I'm sure. I'll check it out now-now. :D PS: Yep, . . . . aVerage windspeed becomes 4.3 m/s, which - with a 2m blade - will generate 311 Watt

Starting torque is useful when there is a lot of cogging resistance. In the air core generators, there is no cogging.

Four blades is 1/3rd more work, I am not sure if it is worth it.

Once you give me figures, I can calculate for 3 and 4 blades.

... may be able to generate that, I have not tested up to that power. You would need to use thicker winding wire than the 1mm I use. You would need blades somewhere between 2 and 2.5 metres long for a standard blade design. For vertical axis Savonius, you would need (it is less efficient) somewhere ...

Does anyone out there have plans for me to build a 3-5kw wind charger? Is a savonius as good as a blade version. I am very new at all of this

Thanks windgat. I'm going to need your help soon.

BTW: I can't get out of a pulley system to get to the voltages I need (minimum ±90V), so I'm considering to go for a 4-blade propellor instead, in order to increase the starting torque.

Is that a good idea

Blade aerodynamics would not be affected.
In fact you performance might just get a bit better due to increased diameter.
You just need to make sure there is enough material clamping the blade.

About the plate. I was already assuming you were using 2 plates

How about if I mounted the blades an extra 20mm out from the centre? Would that throw out the blade aerodynamics? Otherwise carving a bit off the root as you say shouldn't be hard. For the hub, perhaps I'll put a second plywood disk on, ...

... and moving the holes would require some modifications to that jig. Its not impossible but it would probably take us a few months. The part of the blade interfering with your bolts is completely solid (wood) and one solution is obviously just to create a small gap in the blade with a drill. There ...

Years ago (as in jonks ago) I spoke to a professor on the subject of glasfibre reinforcements for helicopter tail blade mountings. He said that you can't use an ordinary glassfibre weave to reinforce the mounting bolt holes. What you need to do is to pre-drill a template and then ...

Hi Greystoke, here is a calculation for your blades. Last two columns are what you are after: blade setting and chord length (linearised for easy construction). Near the root shapes is not important, so just ignore that and make the root in any ...

Ok! I will model some blades for you based on that. Have you factored in power loss in the pulley? And did you do an analysis of 3 vs 1 phase? Or even 5 phase? I take it all yr coils in this design are in series? Here is a very rushed ...

I will help you with the blade profiles... once I know RPM wind speed and desired kW. If you can estimate generator efficiency that would also be helpful. When you are ready , post that (under the Blades section) and I will give you chord sizes and twist angles.

... wire, or maybe multiple stators/rotors. In a 10m/s wind, your actual tip speed would be 60m/s. In a gust of 15m/s, that's 90m/s. Would your blade material handle that? Or would the generator load not allow that speed? I have started to realise that generator load (or resistance torque, or ...

... of turns per coil, ⋅ increased the size of the rotor and stator to speed-up the magnets, and . . . ⋅ gone for a hi-speed 2-blade rotor with a recommended TSR of 6 (not sure yet if I can make such a blade). ⋅ I’ve dropped the wire diameter to 0.8mm, which gives ...

... increased the number of turns per coil, increased the size of the rotor and stator to speed-up the magnets, and ? gone for a hi-speed 2-blade rotor with a recommended TSR of 6 (not sure yet if I can make such a blade). ? I’ve dropped the wire size to 0.8mm diam, which gives me more space ...

... for home builders? I have used two part polyurethane resin, which is liquid and when mixed sets in about 30 min. Perhaps an idea is to make one blade from PVC, and use it to make a mould for another kind of (pourable) plasitc? Hi-density poly in granular form may be a good bet. You could form ...

What plastic do you recommend that's practical for home builders?

I have used two part polyurethane resin, which is liquid and when mixed sets in about 30 min. Perhaps an idea is to make one blade from PVC, and use it to make a mould for another kind of (pourable) plasitc?

... cut-in then the rpm is virtually clamped and for a big range of wind speeds thereafter there is very little increase in rpm. A clear case of the blades being too short !!!! Well Windgat is set up for 1 meter blades with his moulds etc and he said he'd appreciate it if I made 1.5 meter blades ...

... the max speed is 4 - 5m/s. At those speeds I still want a useful power output. I think you may get 1kW out of the design just by doubling the blade length (to 2m). WOW :!: To heat-up a 100L geyser 30 degrees (ie: from 45° to 75°) over a twelve hour period, you need about 300 Watt. That level ...