Dec 31, 2015
Energy producing roads
Roads that procuce energy? Why not? The concept is proven and the next years will see a rise in this type of urban projects. Holland has built a prototype 70 meters bike path and the results so far are very promising.
In its first year of operation, the bike path installed in Krommenie, a town north of Amsterdam, has produced around 3.000kW/h, enough to power a household for a full year. The solar panels in this test road in the Netherlands, have proven that the concept works and roads can become energy producers, although several experts say that because you can't direct the solar cells directly at the sun you have a 30% decrease in production.
Scientists are still finding the numbers behind this first experiment, but appear very optimistic about the future of solar roads.
The technology is accessible, but affordability is still an issue. The 70-meter Dutch bike path came with a price tag of 3,7 million euros. The more roads there are, the more the price will drop, making solar roads more available. Translating the energy production data available so far, each square meter of solar road would generate 70kW/h, annually.
Better than anticipated
The Dutch solar road is being hailed as a success, because it's producing much more energy than expected, even though the panels are not directed to the sun and you have the shadows cast by bikers and other people passing over the solar panels.
The system used in the town of Krommenie uses technology developed by SolaRoad, a local Dutch company, and the creators intend to build a bigger road to test the concept even further.
The solar panels used on this bike path are sandwiched between glass, silicon rubber and concrete, and are strong enough to support 12-tonne fire trucks without any damage. Each individual panel connects to smart meters, which optimize their output and feed their electricity straight into street lighting, or the grid.
So far, the only problem found while using SolaRoad's bike path has been the coating, which provide grip on the surface. Some small sections have lost this covering. It's an issue engineers must solve before the company enters into full production for the next project.
SolaRoad's project is the first of these projects already in use, but many companies try to find the perfect formula for the challenge.
The idea behind SolaRoad is simple: sunlight falling on the road surface is absorbed by solar cells and converted into electricity – the road surface acts as a large solar panel. The electricity generated in this way will find practical applications in street lighting.
SolaRoad is being developed as prefabricated slabs. It consists of concrete modules of 2.5 by 3.5 meters with a translucent top layer of tempered glass, which is about 1 cm thick. Underneath the glass are crystalline silicon solar cells. The top layer immediately shows an important difference from the traditional road surface. It has to be translucent for sunlight and repel dirt as much as possible. At the same time, the top layer must be skid resistant and strong enough in order to realize a safe road surface. This is one of the technical challenges of the entire project.
The Krommenie bike path is a pilot for the system. The road is built in pieces, with all the system pre-built, that are assembled on site, easing the process and speeding construction.
There is still need to develop technology which lets vehicles of more than 12 tons use the solar roads. These surfaces can also be used to cover wide open areas like parking lots, for example, enabling big commercial areas to use these spaces for energy co-generation, hence reducing the energy bill.