Founders of Solar Roadways
Julie Brusaw and Scott Brusaw are founders of Solar Roadways since 2006[6]. Before they came up with the idea of the Solar Roadways, Both Julie and Scott discussed the difficulties of placing solar panels on the rooftop of houses, explaining further that it’s a safety hazard as well as it being a difficulty of maintaining the solar panels. Then that’s when Julie had the idea for the driveway to be covered in solar panels, that way it’s much easier to access the cable corridor, easier to maintain, and imposes no safety hazards. Scott laughed and explained to Julie that it would be impossible because the panels would break from the weight of the vehicles. Due to the fact that Scott is an engineer he couldn’t help but contemplate the possible idea of implementing solar panels onto the road. After much brainstorming with Julie, they realized that they could add heating elements to make the roads snow free, make the road lines out of LEDs, generate a substantial amount of renewable energy, put those transmission lines in the corridors, use it for parking lots, sidewalks, driveways, and the roads themselves. This idea that they had could replace the majority of fossil fueled power plants and act as a unique renewable energy source to power homes and businesses.
Solar Panel
The primary purpose of Solar Roadways is to generate clean renewable energy on roadways[1][2][4][6][7]. If our roadways were to be replaced with Solar Roadways technology, then not only will the solar panels produce enough energy for consumption uses, but hazardous events will also be mitigated. Currently, power lines are either on the poles or underground. These power lines are susceptible to wind and ice damage, and when utility workers have to repair them, they have to climb up these poles to repair them, creating the chances of serious injury. The Solar Roadways technology offers a solution to this problem, a corridor. By adding this corridor, will then the utility workers be able to access the power lines safely and easily.
It’s been estimated that the cause of climate change is resulted from half of the greenhouse gases from the burning of fossil fuels to generate electricity (epa.gov, climate.nasa.gov). If Solar Roadways were to be implemented, then half of the greenhouse gases would be cut, thus reducing pollution and eliminating the dependence of fossil fuels[1][6].
Solar Roadways technology, because it’s an electric roadway, can recharge electric vehicles anywhere and anytime. These electric vehicles can also recharge from home as well.
Electrical
The Solar Roadways technology has a complex electrical layer[1][6][7]. The electric components are placed on a circuit board that’s enclosed between two pieces of glass that’s sealed to protect the components. During the daytime, excess electricity is sent to the grid, and during nighttime, that electricity is then drawn back out of the grid. That way, the system avoids the use of adding a storage system to make it environmentally friendly.
The technology has weight sensors[1][6], so if a boulder were to fall on the roadway, or if an animal is crossing the road, the roadway will be able to detect that abnormality and can warn drivers of the potential hazards in the road.
With Solar Roadways being modular, it’ll be easier to maintain and repair the modules if they were to be damaged[1][2][6]. The damaged panel would then be sent to a repair center. Not to mention, since this technology is equipped with microprocessors, it would have the ability to communicate with other panels and detect a problem if a specific solar panel were to be damaged. It would then report it to a central control center.
The technology also has the ability to shield against EMPs, thus eliminating the potential of electronics malfunctioning.
Glass
The Solar Roadways panels are made of tempered, safety glass.[1][2][6] The glass was chosen for its durability, strength, and hardness. The glass is textured to create traction for vehicles and pedestrians. The major difference between the panel’s glass and the asphalt roads is aesthetics. The hexagonal panels are a work of art that’ll make the roadways, patios, driveways, and sidewalks more beautiful. The hexagonal shape was chosen for its extra stability to wear as well as its flexibility in installing curves, hills, and odd-shaped installations.
Unlike the asphalt roadways, these panels are unaffected by potholes. Repairing potholes on asphalt roadways is expensive, a danger to people, and unnecessarily inconvenient to everyone.
The glass underwent both 3D Finite Element Method analysis and physical load testing at engineering labs. The results showed that the panels can handle up to 250,000 pounds of weight from trucks or commercial airplanes.
The panels are made to last a minimum of 20 years, but could go on for another 10 years. The hexagonal shape was chosen so it could take any force from vehicles and distribute that weight to the surrounding panels, thus increasing the durability and longevity of the panels.
LEDs
The Solar Roadways panels have embedded LEDs[1][6] to replace paint to make road lines and signage. Because of this, it would eliminate the need for paint and the maintenance for keeping up with painted road line marking. Using LEDs instead of paint opens up a lot of possibilities. Roads, parking lots, and signage could become more flexible and customizable.With embedded sensors, the panels could use the LEDs to warn drivers of a potential danger. Safety can also be enhanced by making the roadways more visible, especially in the night time or even if a fog is clouding your vision.
The LEDs in Solar Roadway panels could be used in many different ways to create a more modernized traffic management system. These panels can also enhance the safety of people; the panels can communicate with drivers and pedestrians. Which could mean that crosswalks will be able to flash and tell drivers to slow down when a pedestrian is walking on the crosswalk to the other side.
A lot of people have poor vision at night. With LEDs it would make it much easier to see. The LEDs would also provide more visibility, which could reduce car accidents. The LEDs, combined with heating elements, will improve visibility in all weather conditions, enhancing the safety of the drivers.
Heating
Solar Roadways panels have an integrated heating component.[1][6] The heating system in the panels maintain a temperature above freezing. Because of this, it keeps the roadways free of snow and ice. The implementation of a heated roadway system would save a huge amount of time in snow removal. For homeowners, the panels can provide safe and efficient walking and parking surfaces. It can also remove the need for shoveling and plowing, which is time consuming and may result in injuries. With this technology, homeowners would be saved from winter inconveniences. The heaters only have to keep the surface warm enough to prevent snow and ice accumulation.
The implementation of the panels could provide added safety and eliminate the need for snow plows, shoveling, and road chemicals. According to the US Department of Transportation, the U.S. spends over 2.3 billion dollars on snow and ice control yearly. Poor road conditions are also responsible for many accidents that occur.
Water
Toxicants from damaged road surfaces contaminate waterways[5][6], especially during a storm event, all of the water washes over surfaces that contain debris, chemicals, nutrients, and sediments, as well as many more. All of this causes harm to the environment. As a solution, Solar Roadways integrated a stormwater capture system. In doing so, all of the contaminants that cover the roadways can be washed away by a storm and collected in a tank below the frost line within the Cable Corridor. In the collection tank, the water can be pumped in any direction, such as a water treatment facility, aquifers, agricultural centers, etc. The water collection system also helps prevent hydroplaning and flash flooding by giving the water a channel off of the roadway. In an event of submersion, the panels remain functional, as they are sealed. The panels are also more likely to handle the damages from a storm since they can’t be damaged by wind or hail.
The Solar Panels positioned at ground level would be able to survive hurricanes and tornadoes much better than traditional solar panels hooked up on the roof. Another option for stormwater is treatment and recycling. The resulting water would be undrinkable, it could however be used for a variety of household or business purposes or for irrigation.
Engineering Tests
Four different tests[2] were conducted on the Solar Roadways panels to see if it’s a reliable replacement on our current road system, with the added benefit of producing electricity. These four engineering tests tested the mechanical properties of the pavement material while submerged in water, tested the durability of the panels while subjected to extreme temperature conditions, tested the under dynamic loading conditions, as well as tested the panels by applying shear stress.
The moisture conditioning and freeze/thaw test showed that the extreme weather does not have a huge adverse effect on the panels. There was no defects during the freeze/thaw cycle and no measurable weight gain during the moisture conditioning test.
In the heavy vehicle testing there was no physical damage in the panels. However, only 1/3 of the LEDs in some of the panels remained operational. This as attributed to the manufacturing process.
After the shear test was conducted, it showed that the panels were resistant to the deformation under shear loading.
The results of the four tests shows that the Solar Roadways panels are strong, resilient, and functional.
Calculations
In the 48 contiguous states alone, pavements and other impervious surfaces cover over 112,610 km2 . It’s believed that continuing development will add another 250,000 acres each year.
112,610 km2 = 43,443.54 mi2
This data was used from a report in 2001, so in 2020 -- 19 * ¼ million acres -- So an additional… 4,750,000 acres = 7,421.875 mi2 → 7,421.875 mi2 + 43,443.54 mi2 = 50,865.415 mi2 of impervious surfaces. 50,865.415 mi2 of impervious surfaces contains ⅓ to be rooftops and ⅔ to be pavements. So removing ⅓ for the rooftops leaves around 33,910.28 mi2 of roads, parking lots, driveways, playgrounds, bike paths, sidewalks, etc., that we have.
Solar cells have an 18.5% efficiency. There is an average of 4 hours of peak daylight hours per day, giving us, 4 * 365 = 1,460 hours per year. The company Sunpower offers a 230 Watt solar panel rated at 18.5% efficiency. The surface area is 13.4 ft2, so with what we have ((33,910.28 mi2) * (5,280 ft / mi)2) / (13.4 ft2/230W) → ((33,910.28 mi2) * (27,878,400 ft2 / mi2)) / (13.4 ft2/230W) → (945,364,349,952 ft2) / (13.4 ft2/230W) = 16,226,403,021,564 Watts
That’s over 16.22 Billion Kilowatts. With the average of 4 hours of peak daylight hours (4 * 355 = 1,460 hours per year) We have, 16.22 Billion Kilowatts * 1,460 hours = 23,681 Billion Kilowatt-hours of power! The best way to get the most power from the sun is to angle the solar panels towards the equator. However, Solar Roadway panels can’t be angled for roads or parking lots, only when they go up and down hills. So the national average angle of roads is 0 degrees. A titled solar panel produces an average of almost 31% more than if it were flat, so in fairness, 31% will be subtracted from the total since roads and parking lots can’t be angled. 23,681 Billion Kilowatt-hours * 0.69 = 16,334 Billion Kilowatt-hours
The company did some experimenting and found out that the ½-inch textured glass surface reduced the amount of power produced by solar cells by 11.12%. Subtracting that from the total: 16,334 Billion Kilowatt-hours * 0.8888 = 14,518 Billion Kilowatt-hours According to the Energy Information Administration, The United States used 3,741 Billion Kilowatt-hours of power in 2009.
From that number, it’s easy to see that the company Solar Roadways could produce over three times the power we currently use in the United States.
From continuous research, it’s estimated that around half of the greenhouse gases comes from the burning of fossil fuels to generate power. The company therefore would have the ability to eliminate half of the greenhouse gases being produced in the United States.
Another 25% comes from vehicle emissions. Since Solar Roadway is an electric road, it has the ability to recharge electric cars anywhere. It would also have the ability to charge the electric cars while they’re traveling. With Solar Roadways implemented, it would make electric cars practical.
Problems With Solar Roadways
Solar Roadways presents a solution[1] in terms of renewable energy harvesting but they present a few issues in terms of safety and viability when vehicles are traveling at higher speeds, when wet conditions are present, and steep slopes may also be a problem.
Another problem is the cost of installing Solar Roadway panels. In comparison[3], the France based solar roadway company, named WattWay, created a 1 km stretch toughened PV panels which resulted at a cost of 5.2 million USD. They were also producing around 409 kilowatt-hours per day in the first year since its’ installation which made it significantly less cost-effective.
The Solar Roadways company reported that the panels used about ⅓ of the power they use for their LEDs. Their built-in heating components could also consume its entire power capacity. As for the toughened glass material, it may not give the vehicle the friction necessary to stay on the road or to quickly break. With the LEDs, it may prove difficult to see during daylight times.
Summary
We can’t wait any longer to find a replacement for fossil fuels, which are depleting at a rapid rate. We have the technology to solve this problem at a relatively short period of time.
With Solar Roadways it will: “Create an intelligent, secure highway infrastructure that pays for itself, create an intelligent, secure, decentralized, self-heating power grid, eliminate the need for coal-fired or nuclear power plants, end our dependence on oil and other fossil fuels, cut our nation’s greenhouse gas emissions by over 50%, provide safer driving conditions, snow & ice management, traffic management, wildlife protection, national security, and the usage of recycled materials” (Review Study on Solar Roadways). The panels are proven to be robust, resilient, and functional when subjected to real world conditions.
Although it hasn’t been field-tested whether the panels could withstand under vehicular traffic, along with other problems such as the friction on the glass surface and the visibility of the LEDs during daylight, it is nonetheless a solution that could be hugely beneficial to the United States as well as other countries throughout the world.
