An Idaho company that sees the nation’s energy future tied to highways made of solar power panels last week flipped the switch on its first public demonstration project.
Solar Roadways installed its hexagonal panels in a town square in Sandpoint, 60 miles south of the Canadian border. Company co-founders Scott and Julie Brusaw view their technology -- similar to what's used in rooftop solar panels -- as a way to enhance already-developed land so it can harness clean energy from the sun to power nearby homes and offices.
The company is also gearing up later this fall for a similar project in Missouri, where Solar Roadways panels will be installed in a 12- by 20-foot sidewalk area near a welcome center along historic Route 66.
These decentralized solar projects could provide alternatives to building large solar panel arrays on pristine lands, such as panoramic desert areas in the Southwest.
But the Brusaws are already encountering speed bumps along their solar highway.
A snafu with a lamination machine during the manufacture of the solar panels caused some of the modular units at Sandpoint to fail.
“We’ve got to get damaged panels replaced and make it all perfect,” the Brusaws said in an email to AMI Newswire.
The 150-square-foot Sandpoint project, where visitors can walk or ride their bikes over the panels, is designed to tap solar rays to generate an electric current, which will power nearby restrooms and a fountain, according to a city news release. The more than 300 LED lights embedded in each of the 70-pound panels can be programmed to produce coordinated, colorful light displays as well. They are also equipped with electric heating elements to melt snow in wintertime.
The Brusaws, whose company is located in Sandpoint, are starting small by installing the panels in pedestrian areas and parking lots, but they envision roadways built with the panels, which are waterproof and can be installed on top of existing roads. The couple estimates that replacing existing roads with electrified roads could produce three times the electricity the nation currently consumes while cutting greenhouse gases by 75 percent.
Some observers, however, wonder how maintenance of such high-tech highways could be funded when many of the nation’s roads lie in disrepair. They also question the high price tag of building electrified roadways, which some analysts have pegged at five times the cost of conventional paved roads, and see a diminished potential for generating energy because cars would be constantly rolling over them and blocking the sun's rays.
“In theory, solar (photovoltaic) roadways sound great,” Mark Jacobson, director of civil and environmental engineering at Stanford University, told AMI in an email. “The issue is the cost, which depends on the power output and repair costs, in comparison with PV in large utility-scale arrays on the ground, on rooftops, on parking structures and even elevated above roads.”
The constant wear and tear from cars and trucks would likely lead to higher maintenance costs than in PV projects that are not subject to these stresses, Jacobson said. And black tire dust and diesel exhaust particles, along with cars themselves covering the panels during continuous traffic, would lead to reduced solar power output, he said.
“The advantage is that the road surfaces are already there and don’t require land acquisition costs as PV power plants do,” Jacobson said, “but in PV power plants, panels can be rotated to face the sun continuously and don’t have so much grime settling on them.”
Utility-scale solar projects are now the second least-expensive form of renewable electricity, after onshore wind power, making those projects more competitive in the real-world economy, he said.
“I think it would be difficult for a solar road to compete on cost with that, but this does not mean it can’t if this is done on a large scale with cheaper and cheaper material,” Jacobson said.
Others have questions how the solar roads would operate at night or on cloudy days, especially since the Brusaws’ panels draw power by using LED lights to create road lines and word warnings to drivers.
“The energy can be pulled from either the grid or storage systems when the sun is not shining” the Brusaws said.
In the Sandpoint project, a virtual grid system allows surplus power to flow to the grid on sunny days, while the project can also draw energy when required, the Brusaws said.
In addition, energy storage systems can be used in conjunction with Solar Roadways panels, the couple said.
“Many homeowners tell us they plan to pair our product with Tesla’s Powerwall,” which is a home battery system that stores energy from solar panels during the day so the power can be available in the home at night, the Brusaws said.
Cost comparisons with conventional roads remain an unknown because the company has yet to begin mass-producing their products, they said. In addition, the roads’ ability to generate energy will help offset costs, as will the reduction in snow plow runs. Another potential cost offset, they said, is the ability of such roads to carry electrical current, thereby reducing the need for overhead power lines.
The Brusaws said they expect the life span of highway solar panels to exceed that of conventional roads. “We won’t know for sure until we have that real-world data, but we think 20 years or so,” they said.
An even more futuristic concept could allow solar roads and highways to charge electric vehicles while they drive. The Brusaws’ company is now in talks with a consortium headed by Utah State University to develop a coil induction system within an electrified roadway that would provide dynamic charging for EVs, thereby increasing their range, according the Solar Roadways website.
So far, the company has gained financially from private and public interests, including three federal Department of Transportation grants as well as millions of dollars in donations through a crowd-funding website.
“The Solar Roadways project is revolutionary technology,” Sandpoint Mayor Shelby Rognstad said prior to the demonstration project’s debut. “It can change the face of the world and how we travel.”