February 25, 2016
If we want to prevent global warming from taking on really dangerous forms, we need to adopt unorthodox measures. A good example of this is SolaRoad, a road surface that generates energy. TNO senior advisor Sten de Wit explains how this has been achieved in six steps.
1. THE SUN AS PROVIDER
“The energy source for the SolaRoad is not the road itself but the sun. This provides energy to solar panels placed in the road surface. You start with a base layer of concrete. The solar panels lie on top of this, and the final layer is a coating that needs to be strong, rigid, and – of course – transparent. The road surface is laid at a slight camber, so that dirt is washed away with rain water, thus avoiding the need for cleaning. There also needs to be a connection with the electricity grid in order to be able to extract the energy. Actually, that’s all there is to it.”
2. ROADS INSTEAD OF ROOFS
“The total surface area of roads in the Netherlands exceeds the total surface area of all roofs in the country. Furthermore, the roads are already there, which means that the panels are easy to install within the built-up environment. However, not all roads are suitable. It’s best to begin on the smaller roads and in places where there are fewer shadows. If we install SolaRoad on ten percent of these roads, a total length of around 12,000 kilometres, then that is more than enough to make the system profitable. That’s partly because the panels will quickly become cheaper to produce. This doesn’t mean that solar panels aren’t needed on roofs. To achieve climate targets, we need to utilize all options.”
"If we install SolaRoad on ten percent of these roads, a total length of around 12,000 kilometres, then that is more than enough to make the system profitable"
3. POSITIVE PILOT
”We are conducting a pilot on a cycle path near Krommenie, in conjunction with the Province of Noord-Holland and a number of commercial partners. The experiences from this are positive. Initially there were problems where the coating came off in a few places, but this seems to have been resolved. We also asked the opinion of cyclists, whose response was neutral: in other words, they could not distinguish this surface from that on a normal cycle path, which was just the response we were hoping for. The result? In the first year, a seventy-metre length of cycle path produced 9,800 kWh energy, enough to supply three households. And that was just using one lane.”
4. STEPPING UP TO HIGHWAYS
“The demands of a cycle path are not as great as for a highway. But even on a cycle path you sometimes get cars or tractors, which means that the construction needs to be strong. In time we will work on roads that are intended for traffic. When that happens you can also begin thinking about supplying power direct to electric vehicles.”
5. INTEREST FROM THE USA
“There has been interest from abroad in the SolaRoad. The idea is to carry out tests in California. The situation is different there, so it gives us a new challenge. Other surfaces are also possible, such as airport taxiways, or even the decks of ships. But that is for the future. For now, we are quite busy enough working on cycle lanes and roads.”
"Other surfaces are also possible, such as airport taxiways, or even the decks of ships"
6. SMART THINKING
“The question is not if the SolaRoad will part of our lives, but where and when. In the foreseeable future the technology will be sufficiently robust and at the very least recoup its cost. I expect that we will be laying SolaRoads within about four or five years. We need to think smart. By, for example, laying these surfaces on roads where there are already road works underway.”