One of those brilliant ideas that I wish I had thought of first: paving roadways with electricity-generating solar cells. Idaho-based startup Solar Roadways have been awarded $100 000 to develop their road-based solar panel technology:
The 12- x 12-foot panels, which each cost $6,900, are designed to be embedded into roads. When shined upon, each panel generates an estimated 7.6 kilowatt hours of power each day. If this electricity could be pumped into the grid, the company predicts that a four-lane, one-mile stretch of road with panels could generate enough power for 500 homes. Although it would be expensive, covering the entire US interstate highway system with the panels could theoretically fulfill the country’s total energy needs.
Furthermore the panels would create road markings with embedded LEDs.
It occurs to me that roads are the perfect media for ground-source heat pumps as the constant passage of cars heats up the road surface, even on cold days. When a new road is laid down (or an existing road is resurfaced) you fill it with the necessary pipework and plug it into the heating systems of nearby houses. Heat pumps would be more useful in urban areas of more northern, colder countries than solar panels due to shorter days in the winter.