Solar is a highly efficient way to heat water. Combine it with underground storage, and a year-round system can be created where the system can cover heating requirements in the winter and cooling in the summer.

The Dutch company Ooms Avenhorn Holding BV has taken this concept and moved it a step forward with the Road Energy System^® (RES).

Rather than putting tubes on a rooftop, RES lays the collection system within concrete -- like the black asphalt of a road or runway. The piping connects to underground storage areas. Remember the last time you walked on black asphalt on a sunny August day, and you'll understand the heat being transferred into the water in the pipes.

This water is then transferred into the storage area. On demand, in cold weather, the hot water is used to heat buildings and to keep the road above freezing. After cooling, the water is moved into cold storage to provide air conditioning for summer months.

This creates a year-round solar/geothermal heating/cooling system for both the road and buildings. The renewable combo greatly reduces electricity requirements (and thus pollution), and the cooling/heating of the road reduces maintenance requirements by lowering/eliminating the deicing and plowing requirements in winter.

And it is deployed: "Solar Energy collected from a 200-yard stretch of road and a small parking lot helps heat a 70-unit four-story apartment building in the northern village of Avenhorn. An industrial park of some 160,000 square feet in the nearby city of Hoorn is kept warm in winter with the help of heat stored during the summer from 36,000 square feet of pavement. The runways of a Dutch air force base in the south supply heat for its hangar."