Flying Wind Farms

This article, from the Economist, discusses a design by Sky WindPower, a San Diego based company, which takes the form of a kite with four helicopter-style rotors.

The rotors keep the kite afloat, 10km up in the atmosphere, where wind speeds are extremely high, and also drive dynamos, that generate electricity, which is transmitted to the ground.

When the winds are low, the dynamos can be reversed, to keep the rotors spinning and hence maintain the kite's height.

Rotating Solar House

This article from Sci Fi Tech talks about a house in Freiburg, Germany that has a huge array of solar panels on its roof.

It rotates during the day, to maximise the amount of radiation caught by the array.

Looks like it's in a nice location, too, so rotating means the occupants get to enjoy the scenery.

Clever Bike Gear System

The NuVinci Continuously Variable Planetary Drive is based on an invention of Leonardo da Vinci.

The video explains it well, but the basic idea is that the rider turns the handle and the input to output ratio changes smoothly.

Seems very clever. Maybe it's finally time for me to learn to ride a bike!