There are 2.7 million miles of public roads in the United States, and in the past we’ve seen several innovative designs that transform these paved surfaces into energy and heat-generating solar roads. One company, Solar Roadways, has even come up with a prototype solar panel for roads, however they are expensive ($7,000 each) and it has been estimated that the cost for transforming the whole country’s roads solar would top $35 trillion. Faced with this is ridiculous cost, the University of Rhode Island has come up with four feasible methods for super-charging our roads with solar power – read on for a look at each!
The first method is to gather solar energy from Jersey Barriers, the walls that are often used to separate opposite lanes on narrow roads. The research team from the University believes that if flexible photovoltaic cells were installed along the tops of these barriers, then the energy collected could be used to power street lights and road signs.
“This is a project that could be implemented today because the technology already exists,” said K. Wayne Lee, URI professor of civil and environmental engineering and the leader of the team. “Since the new generation of solar cells are so flexible, they can be installed so that regardless of the angle of the sun, it will be shining on the cells and generating electricity.”
Lead Image © Wolfgang Staudt
Image © University of Rhode Island
Another method would see the installation of water pipes under the roadway. Heated water could be flushed through the pipes to melt ice one the roads, making them safer to drive on. It would also eliminate the need for salting roads, which would reduce carbon emissions related to hauling and spreading salt by truck. Graduate student Andrew Correia has built a prototype of such a system in a URI laboratory to evaluate its effectiveness. “One property of asphalt is that it retains heat really well,” Lee said. “My tests showed that during some circumstances, the water even gets hotter than the asphalt.”
The third options uses the thermoelectric effect, which occurs when hot and cold spots are linked by semiconductors. By planting semiconductors at different depths, the heat from the asphalt can be collected.
Finally, the last method is the most expensive – replacing asphalt with self-contained, durable modules that include photovoltaic cells and other equipment to generate electricity and provide illumination. Due to the costs and technology needed, this is the most unlikely approach. However Lee believes it is inevitable. “This kind of advanced technology will take time to be accepted by the transportation industries. But we’ve been using asphalt for our highways for more than 100 years, and pretty soon it will be time for a change.”
Via Energy Matters