The tech behind smart cities

Solar farms take up valuable land space, so French company Ciel & Terre developed a floating version that sits atop bodies of water.

Ciel & Terre's fixtures (which hold slide-on solar panels) can be anchored in anything from industrial water ponds and dams to canals and irrigation reservoirs.

The panels are made of recyclable materials, easy to install and generate renewable energy. The technology is even safe to put over drinking water reservoirs.

The first Ciel & Terre plant was installed in Piolenc, France, in 2011; the largest floating installation -- which has 4,536 solar panels -- is in Okegawa, Japan.