Simon Gripenberg, an artist from Finland, developed new types of vertical windmills, inspired by ancient Persian windmills and built from recycled materials. Most interestingly, the windmills float in water or spin on ice, so that Gripenberg manages to obtain low friction at low cost.
The vertical windmill on ice uses a number of skis to benefit from the low friction of the ice. The windmill spins around an axis that is fixed into the ice. The small prototype works very good, but if scaled up in size it would be necessary to take lifting forces into account. [Video]
A similar concept is applied to a vertical windmill floating on water, contained within a rigid structure. The windmill rotates smoothly with the use of a simple water bearing. [Video]
Gripenberg also made a wind-powered carousel from a 6 ton ice sheet. [Video]
Images: Simon Gripenberg
