Missouri is about to head down the path of exploring the use of solar panels on its highways, but don’t expect to see miles and miles of roadways paved in glass any time soon.
While the sun might be the key to the future of Missouri highways, the state will begin that journey with a modest step — a small section of sidewalk at the historic Route 66 Welcome Center off Interstate 44 in Conway, Mo.
“We want to start kind of smaller and just be able to test the initial application and see how it installs,” said James Pflum, resident engineer with the Missouri Department of Transportation’s Kansas City District.
“Right now, it’s kind of baby steps. It’s testing the sidewalk and seeing what works and what opportunities we have and what questions we need to answer. But from there, we would go to parking lots and then hopefully to roadways.”
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From what state officials can tell, Missouri would be the first state department of transportation to use the technology. State officials are interested because they see it as a way to possibly save money and generate revenue from the more than 33,890 miles of highways the state maintains.
The LED lights in the solar panels, for example, could replace striping and other highway markings. The heating elements could melt snow and ice. The panels also can generate energy.
“We are not necessarily looking at if the roads can generate wholesale power, rather whether they can generate enough to power a rest stop,” Pflum said.
The state could theoretically sell the excess power to fund future transportation projects.
The Missouri Department of Transportation is expected to announce this week that it has reached an agreement with Solar Roadways of Sandpoint, Idaho, to install and help test the company’s solar panels for use on roadways.
By the end of this year, crews will install solar panels on a roughly 12-foot-by-20-foot area of the main sidewalk, said Laurel McKean, assistant district engineer with MoDOT’s Southwest District in Springfield.
Transportation officials will help test the panels to see how they handle freeze-thaw conditions in Missouri, how much energy they produce and how effective they are at melting snow and ice. Testing will also check whether LED lights in the panels can take the place of traditional pavement striping.
“There’s a lot of things that by putting the panels on the sidewalk we are going to be able to test to help them look forward to their next phase of development,” said McKean, who is leading the project.
The ideal part about using the welcome center as a test site is that there’s plenty of room to grow, she said.
“With the welcome center, you could have that next test of either putting in a parking lot and having cars park or drive on it,” she said. “Or you could even extend it out to the entrance ramps into the welcome center from the interstate, so that way it would get that daily, higher-speed traffic on it.”
Solar Roadways makes the six-sided panels that are just over 4 square feet in size. Each panel weighs about 70 pounds. They have a top and bottom layer of half-inch thick tempered glass. The glass has a textured surface to create traction for vehicles and pedestrians.
The panel’s solar cells, LED lights and electronics are laminated in between. Each solar cell is a sandwich of a positive-type and a negative-type silicon that generates electricity by using sunlight to make electrons “hop across the junction” between the two types of silicon. The electricity that is generated will be converted and fed into the welcome center building.
The panels are installed similar to the way a wood or tile floor is installed. The individual panels are interlocked to create a surface. They also communicate with one another. If a panel goes bad, only that panel has to be replaced, not the whole array, McKean said.
For sidewalk installation at the Route 66 Welcome Center, two concrete sections of a sidewalk will be replaced. Installers will make sure that the aggregate base hasn’t eroded. The panels will then sit on that base. When used for roadways, the panels might need to be placed on a pavement or concrete base, McKean said.
MoDOT is testing two panels at the St. Louis Transportation Management Center to see how much energy can be generated.
Because only about 40 panels will be used for the sidewalk test, not a lot of energy is expected to be produced. Transportation officials will track how much energy is generated and what has been used on a daily, monthly and seasonal basis. The project will cost $102,000, which is coming from federal funding earmarked for research purposes.
“There are a lot of unknowns still,” McKean said. “To me, that’s what’s exciting. We are going to be learning as this gets deployed.”
The project is one of several identified under MoDOT’s Road to Tomorrow Initiative, an effort to identify innovations that would help it rebuild its transportation system to meet the needs of the future while searching for sustainable revenue streams that can provide funding.
The transportation department this spring unveiled several pilot projects in Kansas City to address future transportation funding.
“A lot of state DOTs have been looking at what is the future going to hold and what is the new technology,” Pflum said. “MoDOT took it a step further and really started asking the question of what is the future technology going to be and can there be revenue generation from it. We are really focused on new technologies that increase our revenue streams.”
Once the initial testing is complete, transportation officials hope to turn to crowdfunding to raise money for expanding the test and determining if crowdfunding could be an option to generate money for other transportation projects.
“Whether we get a lot of money or not, it’s still going to be interesting to see how that funding option can work,” McKean said.
The selection of the Route 66 Welcome Center has already created a lot of buzz, even though the solar panels will not technically be on the historic Route 66.
“This is kind of cool … to think that we are looking at the past, which everybody calls ‘The Mother Road,’ to maybe potentially look to the future,” McKean said.