Last month, Hawaii received $1.7 million in grants to modernize its electric grids to accommodate an influx of renewable energy, with an eye toward electric cars. Why Hawaii? The geothermal power . . .

This electric helicopter has coax rotors, so it doesn't need a tail rotor, which consumes up to 25% of the energy in conventional helicopters, to stabilize them. It's also much quieter than conventional helicopters, as tail rotors make 30-40% of the noise

A global emission trading scheme will not work. Instead, an international agreement should set targets, with technicalities worked our locally, backed up by trade sanctions. Feebates work best to achieve reductions.

Since July 2007, a program called Vélib' has dotted Paris with 10,000 electric hire-bicycles, stationed in 750 bike ranks. To drive them, you'll need a one-year membership, which can . . .

The image on the right shows the Anderson Mill, in Travis County, Texas, which was built in the 1850s as a corn mill. Since ancient times, waterwheels and wind mills have been used to grind grain to produce . . .