When SolaRoad launched, I expressed some serious doubts about the logic of putting solar panels under a bike lane, noting that "I still find it hard to think of a worse place to put solar panels than in the road, except perhaps in my basement floor" Now it has been in operation for a full year, and the developers are calling it a huge success. The $ 3.7 million project has generated 9,800 kWh, which at $0.20 per kWh is worth a whopping $1,960! That's a 0.0057 percent return on investment!
Now of course this roadway was a prototype and would cost a lot less if mass produced. But solar plants in Germany are now delivering power at 9 cents per kWh. It's predicted that by 2025 it will drop to between 4 and 6 cents per kWh. The Solaroad people claim that their system will pay for itself in 15 years, but at those rates it will cost more to rake the leaves off their solar panels than it will get out of them in electricity. Yet Sten de Wit of SolaRoad continues to be optimistic about paving the country in solar panels. He is and is quoted in Fast Company:
Adele Peters of Fast Company goes so far as to claim that "A solar-paved street could ultimately be cheaper than something made of asphalt or concrete."
For cities and agencies responsible for building and maintaining roads—mainly governmental agencies—this is an interesting proposition if the total cost of ownership (sum of costs and benefits from energy production) of such a road over the life cycle would be comparable to or lower than with current roads. With SolaRoad we are developing such a road.
I am sorry, but that defies logic. The solar roadway has to sit on top of a very stable and strong concrete base, and the return on this investment is not fifteen years, it is never.
It's true that the SolaRoad can do many other things, and the designers have visions of it improving traffic management, having lighting, signage, or even ultimately wireless energy transfer to cars. It may then make sense to power all these neat things with solar power. But how do you define success in something like this? According to Triple Pundit, "The primary goal was to perfect the road’s durability and functionality, which has been accomplished."
OK, they have proven that they can do it. They still have not proven that it makes any sense.