graphic: Dan Walden
feature
solar highways by: mike howe
ver the past decade or more there has been a significant push to move toward green energy. Any over-theroad trucker has witnessed this firsthand as the scenery has evolved from blowing trees and tumbleweeds to large wind turbines churning out electricity. What once were vast fields now stand ever sprawling wind and solar farms. And, as globalwarming discussions intensify and tensions in the Middle East continue to escalate, there is consistent pressure for the United States to wean itself off foreign fossil fuels and become more clean-energy independent. While wind power seems to have received much of the renewable-energy attention over the past decade, solar power continues to be a source many look at as the ultimate solution to the nation’s long-term energy needs. One innovative company has identified a unique opportunity for the nation’s highway system and solar energy to unite in conquering the clean-energy challenges facing the country. Imagine, if you will, driving your truck down the highway,
O
18 C H A L L E N G E A P R I L 2 0 1 2
but instead of the traditional paved highway it is a solar highway. That’s right, a highway that is basically one large solar energy system. This is what Scott Brusaw of Solar Roadways (www.solarroadways.com) envisions. Scott and his wife, Julie, had long been concerned about global warming, and one day Julie asked Scott if the vast amount of highways couldn’t be turned into solar roads to solve the energy problems. Scott, who is an electrical engineer with more than 20 years of industry experience, was intrigued by this question and began to research it a little. “Interestingly, the inspiration and research goes quite a ways back for Julie and I,” says Scott. Julie and Scott have known each other since they were about 4 years old. “Her mom used to babysit me, and I remember playing with those old race tracks with the electric cars. That’s really probably the beginning of the entire story,” says Scott. Of course, the idea has developed quite a bit since then.
Among the first questions is whether developing solar highways is even feasible. The Solar Roadways website has a number of statistics that suggest it is. The website notes, “In the 48 contiguous states alone, pavements and other impervious surfaces cover 112,610 square kilometers – an area nearly the size of Ohio – according to research published in the 15 June 2004 issue of Eos, the newsletter of the American Geophysical Union. Continuing development adds another quarter of a million acres each year.” Doing some quick math that eliminates rooftops, that leaves about 29,000 square miles of roads, parking lots, driveways, playgrounds, bike paths and similar paths to use with this project. Based on current commercially available solar-panel-efficiency data, using an average of only four hours of peak daylight hours per day with a 230-watt solar panel, and covering the entire 29,000 square miles, the amount of electricity generated would be more than 13.8 billion kilowatts. The amount of energy one can realistically expect to produce on the highway is interesting too. The solar panels are 12 feet by 12 feet and produce 7.6 kilowatts per day based on four hours of good sunshine, with about a 15 percent efficiency rating. A mile of road requires about 440 panels. So, a four-lane highway will produce about 13.376 megawatts per mile. The average home, according to the Energy Information Administration, uses 936 kilowatts per month. Certainly, the energy output is significant. After researching the concept and putting real numbers to it, Scott and Julie learned that it could be done and there was enough material available to make this a reality. “We then started a website and decided to apply for grant funding in 2009,” says Scott. That year, they received a $100,000 grant from the Federal Highway Administration (FHWA) to test the theories and build a prototype solar road panel. “This enabled us to go down the road of developing a highway that can pay for itself over time,” says Scott. The initial grant helped fund Phase 1 of the project, and this was completed in 2010. “Once we completed Phase 1 we submitted our final report to the FHWA,” says Scott. “We also applied for an additional $750,000 in FHWA grant money for Phase 2.” That phase would be a two-year contract to essentially take the lessons learned from Phase 1 and improve upon them. FHWA awarded them their $750,000 Small Business Innovative Research Phase II grant last July. “The plan with that is to begin retrofitting our own parking lot for testing,” says Scott. If the idea is to develop a solar highway, why are they retrofitting a parking lot first? “FHWA told us that they weren’t going to alw w w. p t c c h a l l e n g e . c o m