The amount of energy that you get out of a wind turbine is directly proportional to three things:
- Wind speed
- The frequency with which the wind blows
- The area of the rotor facing the wind.
- (It’s also proportional to the mass of the wind, but for all practical purposes that can be taken as a constant).
You will come across all sorts of crazy idea on the Internet about how someone has come up with a new design of a wind turbine that extracts more power, but the under-lying physics can’t be gain-said.
If you are into mathematics and physics, you can read up the physics of wind generation here. Which is why all serious wind generators use those huge white three-bladed turbines on the tops of hills. Which cost a huge amount of money, and generate a huge amount of resistance from the local population.
Small VAWTs can go on roof tops and be hooked into the micro-grid, or they could be used stand-alone, to, say, re-charge the batteries used in an electric fence.
A degree of meteorological research is needed first, to get values for (1) and (2) above, to get an idea whether any sort of wind-turbine would be cost effective. Vertical axis wind turbines have other advantages over the “big windmill” type in that they are usually quieter, and less visually obtrusive.
I would envisage that wind-power of this type would a subject for longer-term research by the technical people living and working in the village, rather than something that is implemented early on.
One potential use for small VAWTs (with small batteries) is in distributed and portable electricity requirements, like moveable electric fences for use with variable grazing systems. There’s a lot of design work to be done there.