Simplified DIY Rooftop Wind Turbine
This article is about building a high-efficient yet simplified DIY Rooftop Wind Turbine. Needs cooperative work, though. Feel free to add info.
Can be achieved by incorporating
- Tilt-up or freestanding design
- Variable pitch blades and
- Furling tail
- Fixed coils (so no brushes/slip rings are necessairy)
In practice 
The designs mentioned may be incorporated into already good, opensourced wind turbines (eg Hugh Piggot, Jua Kali Wind turbines, ...) Also, to make an even better system, it may be incorporated into the motorwave micro turbine array. This fan-array would achieve the best rooftop performance system (while still allowing easy repair, revision, ...). The fan array may, rather than being equipped with a rotatable mounting to constantly change to the direction the wind is coming from, be equipped with a rail system. The rail system can then turn the entire array (instead of all of them seperately) towards the wind. The rail system may receive the information from where the wind is coming from from a automated system with seperate wind direction meter.
2 designs may be created; one large design with a freestanding tower and another with the modified fan-array. They could make use of following innovations:
- Tilt-up design
- Variable pitch blades and furling tail
- Fixed coils
Other designs 
Possible other designs for the low-cost turbine may incorporate the Savonius wind turbine http://static2.instructables.com/id/Build-a-Savonius-Wind-Turbine-or-VAWT-to-make-elec/ http://static2.instructables.com/id/A-Home-Power-Plant---Wind-Power-Generator-Revised/
Or some other special designs (Swift home turbine, piezoelectric windmill project, Motorwave micro turbine; the last one is possible the most intresting) http://en.wikipedia.org/wiki/Wind_turbine