Arian de Bondt, an engineer at Ooms, came up with a great idea. Use the heat generated by the sun on the road in summer to heat water that you'll later use in winter to heat a building and melt road-ice... then use the cold water that comes out of this process, store it again, so you can use it in summer for cooling.
Reminds me of the water cooling project in Toronto that uses lake water to air condition buildings... but even smarter. Well, if you've got an aquifer on hand :)
Via The Economist