Solar Roads: Renewable Energy Solution Or Pipe Dream?

“There is not the slightest indication that nuclear energy will ever be obtainable. It would mean that the atom would have to be shattered at will.”— Albert Einstein

Snow removalI came across the Solar Roadways project last month from an article on Fast Company’s Co.Exist website. The basic premise of the project is that if all the roads in the country were “paved” with solar panels they would produce more energy than the country consumes in a year. The article also discussed some of the features of the solar panels like embedded LED lights for dividing lines, heaters to keep the panels free of snow and ice, and the tempered glass that can support a 250,000 pound vehicle and is textured to provide traction. The article also mentioned that the owners of the company developing the project were currently trying to raise $1 million on the crowdfunding site Indiegogo in order to hire additional engineers in order to perfect their product.

My initial thought was that it is a pretty cool idea but I didn’t think that implementing it would be practical or feasible.  I had almost forgotten about the project until videos about it started popping up in my Facebook newsfeed over the past several days and I decided to take another look. The project has gotten a ton of attention over the last several weeks and appears to have garnered as many detractors as it has supporters. They’ve easily surpassed their crowdfunding goal of $1 million raising over $2 million as of yesterday morning with another nine days still to go for their campaign.

The Solar Roadways project started back in 2006 by founders and inventors, Scott & Julie Brusaw. They received Phase I funding through the U.S. DOT’s Small Business Innovation Research (SBIR) program in 2009 in the amount of $100,000. This funding allowed them to build a 12-ft by 12-ft prototype to test out the electronics with a separate system to test the solar energy collection. This led to an additional $750,000 in Phase II funding through the SBIR program in 2011 to build a prototype parking lot.

In Phase II they were able to perform load, traction and impact resistance testing on the glass for the panels. They also reduced the size of the panels and changed the shape. The new panels are hexagon shaped and measure roughly 4 square feet. The prototype parking lot measures 432 square feet and the panels are fully functional with solar cells, LED lighting, heating elements and the textured glass surface. Once the Phase II contract wraps up in July they are expected to be able to calculate what the costs would be to manufacture their panels.

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One good thing the company behind this project has going for them is they only have to find the best way to implement their project and make it cost effective to manufacture on a large scale. There are plenty of companies and scientists out there doing research on the major components of these solar roadway panels. Thanks to nanotechnology and other breakthroughs, solar cells are being developed to be more efficient and capable of absorbing the entire spectrum of sunlight at any angle meaning the panels won’t have to be tilted to be more efficient. There are a number of lighting companies that are making LED lights brighter, cheaper and more energy efficient glass manufacturers developing ways to make glass stronger and more durable.

The project has received some harsh criticism from people who think the concept isn’t feasible. Some of the critics have been pretty mean-spirited going as far as accusing the inventors of being scam artists by raising funds for their project through Indiegogo. Despite the attacks on the concept, most of the blog posts and articles I’ve read against the project do raise some valid questions, most of which have been addressed on the company’s website.

I don’t think they are doing themselves any favors with having the quote “Our technology works. Now it’s time to gear up for manufacturing”, while at the same time stating that they need to hire more engineers to further their research and development. They also have a video and some photos of a tractor being driven on their prototype project. The problem is the tractor appears to be a John Deere 3038e which has a lower curb weight than a Honda Civic so it’s probably not a great example of the prototype parking lot in use. One of the promotional videos shows the inventors loading crushed colored glass into a wheelbarrow when talking about using as much recycled material as possible. One critic correctly pointed out that turning colored glass into clear tempered glass panels would not be economically feasible. That glass was actually used as aggregate for the base layer that the panels are placed on top of and not to create the tempered glass for the panels.

Let’s assume that the cost to manufacture, install and maintain the solar panels would pay for themselves over the course of their lifetime through the sale of the electricity generated. The biggest obstacle I see to the project is I haven’t seen raised is how long it would take to install these panels on a road and what kind lifecycle the panels will have when they have thousands of vehicles driving over them and parking on them every day for 15 to 20 years. In one of the company’s videos it shows two people manually installing each panel one at a time.

It seems like it would take forever to prepare an existing roadway, dig the raceways for the transmission lines and the proposed stormwater treatment system and then lay each tile by hand. Even after the tiles are placed you need to go back in and install covers for the mounting holes and place mastic between the tiles. Maybe someone needs to start engineering heavy equipment to quickly and efficiently pave the roads with these solar panels. Logistically I would think that you would basically have to close the road and reroute traffic which won’t be possible for every road in America and I doubt the DOT will allow them to be placed on roadways without thoroughly being tested and proven to withstand years of use.

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I still don’t think the idea of solar roads should be dismissed wholesale. The quote at the beginning of this post is proof positive that very intelligent people can be very wrong when it comes to predicting the feasibility of future technology. Lord Kelvin, who accurately calculated the temperature of absolute zero, thought radio had no future and that x-rays were a hoax. He was proven wrong on both counts and even had his hand x-rayed. Thomas Edison also derided alternating current as a waste of time but I’m not sure if he actually believed that or if it was more because he was promoting his own direct current technology. My point is that just because something doesn’t seem practical or feasible today doesn’t mean it won’t be someday in the future.

Paving roads with these solar panels may be decades away but I could see the company marketing these commercially for driveways, parking lots, sidewalks, greenways and residential developments.  They’ve even received letters of interest from places like Wright State University, Boise State University and NASA’s Kennedy Space Center. So, while I don’t think we are going to see all of America’s highways and byways being covered with solar panels in the next decade or two, I do think we will see solar panels on other paved surfaces in the next few years.

8 Responses to “Solar Roads: Renewable Energy Solution Or Pipe Dream?”

  1. Frantz Cartright June 12, 2014 at 10:49 AM #

    It took a long time to get the technology of our roadways the way it is now and research in that area is still very active because what we have now requires too much maintenance specially in the northern parts of the country. The present materials expand and contract with temperature and every time we salt the roads, we are actually destroying them. So we are constantly re-building roads. These costs are probably well over $100 billion at the federal level and increasing each year and that is just to keep up! It is unfair to compare an emerging use of existing technology with a technology use that has been around and under development for a century. Maybe the Brusaws won’t succeed with the roads right away but if they work it out for driveways and parking lots it will be very very huge. Give them a break and let us support American know-how, American innovation and American technology. The Brusaws have enough problems to solve. They don’t need us to put them down for every single little aspect of what they say or what they do. Let us wish them all the best.

    • KendallEJones June 12, 2014 at 11:07 AM #

      Thanks for the comment Frantz. I actually like the idea they are proposing. Obviously they still have a ways to go with field testing before we start seeing roads with solar panels popping up everywhere. I agree that if it’s proven in driveways and parking lots it’s going to be big.

  2. James Bagley June 12, 2014 at 11:14 AM #

    There are plenty of places these could work very well, but imagine the road building industry would not be in favor of and will fight cutting into their virtually unlimited costs for construction, repair and repaving of roadways – normally based on unit pricing of materials placed and quantity of work completed.

    I would also use the new technology of photovoltaic grids on metal panels – on most metal roofs, on the tops, hoods and trunks of most cars and all 18-wheelers and golf carts, converting the electricity to run the vehicles and generators turning on every axel to keep it going even longer. The same metal panels on as many roofs as feasible.
    Highway medians…manage the trees in a planned manner and sell it; lease the land for farming but at least for hay fields…much of it is already flat and level enough for farming equipment to operate efficiently. Same for right-of-ways for power lines and pipe lines — which could be another easy place to locate the panels discussed in this article.
    Best wishes to you in this endeavor!!

    • KendallEJones June 12, 2014 at 11:46 AM #

      Thanks for the comment James. One of the things the people behind Solar Roadways are looking into is installing induction plates into their panels so they can wirelessly charge electric vehicles while driving. They are also looking into adding piezoelectric generators to harvest the mechanical energy generated from passing traffic.

      • Guy Colangelo June 12, 2014 at 1:17 PM #

        The idea is superb and solves many problems. Just wondering if this is feasible vis-a-vis costs? Are there benefits to home owners in the short term to get this moving in the right direction and then implemented for commercial use?

        • KendallEJones June 12, 2014 at 1:51 PM #

          They haven’t determined what the cost will be to produce these commercially. I’m guessing they would have to get approval but I don’t see why homeowners wouldn’t be eligible for the same tax credits available for conventional solar panels. The other benefit is reduced power bills.

  3. RickFreeman June 12, 2014 at 12:50 PM #

    I see some interesting engineering problems to overcome. I’m not naysaying, just curious. How will they achieve a sufficient coefficient of friction for safe operations at highway speeds while being able to withstand the abrasion from road grit? Will they have to periodically ‘polish’ the surface as dirt and grime accumulates? I’m also curious about what happens to the panels during a crash. I can just imagine a semi sliding along after an overturn.

    • KendallEJones June 12, 2014 at 1:29 PM #

      Rick, the tempered glass they are using is textured and has been lab tested for traction. I don’t know if they have done any tests as to how that will be affected from abrasion. I believe they are looking into coating the glass with self cleaning coating on the glass. I think they have tested for impact resistance but I don’t know what the results were. I agree that they will have to do a lot of real-world testing on these panels to see how they hold up over time.

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