The question of the month – how come no one thought of this before? Dutch company Ooms Avenhorn Holding BV has brilliantly landed on the most obvious attractor for solar energy – asphalt.

The company's Road Energy System has collected solar energy from a 200-yard stretch of road and a small parking lot to heat an apartment building, and an industrial park of about 160,000 square feet is warmed in the winter with heat stored during the summer from 36,000 square feet of pavement. Plus, it's also heated an air force base hangar with the runways.

The possibilities are endless – our airports could be heated from the runways, our malls could be powered by the parking lots, etc. An article in the San Francisco Chronicle describes how the system works:

A latticework of flexible pipes, held in place by a grid, is covered over by asphalt, which magnifies the sun's thermal power. As water in the pipes is heated, it is pumped deep under the ground to natural aquifers where it maintains a fairly constant temperature of about 68 F. The heated water can be retrieved months later to keep the road surface ice-free in winter.

Though it doubles the cost of construction, the system is designed to provide longer life for roads and bridges, fewer ice-induced accidents and less need to repave worn surfaces.

But the same system can pump cold water from a separate subterranean reservoir to cool buildings on hot days.

It is usually necessary to heat the water a bit more when it is retrieved later, and the installation costs are pricy, but lowered heating bills and a 50 percent decrease in carbon dioxide emissions make up for all that.