Solar roads are an innovative concept designed to transform road surfaces into sources ofrenewable energy. The technology involves covering roads, parking lots or cycle paths with slabs or paving stones containing photovoltaic cells to capturesolar energy and convert it into electricity.
How do solar roads work?
These slabs are generally made from tough, resistant materials, such as tempered glass, to withstand the weight and traffic of vehicles. Solar roads are designed to withstand weather conditions and offer grip similar to that of conventional roads. What’s more, some slabs are equipped with LEDs to display road markings or warning messages.
The electricity generated by solar roads can be used to power street lighting and surrounding buildings, or fed back into the power grid. This concept offers a number of advantages, such as reduced dependence on fossil fuels, increased production of renewable energy and a reduced carbon footprint.
However, solar roads also face several challenges, such as high installation costs, maintenance and economic viability. Several pilot projects have been set up in countries such as France and the Netherlands to study the feasibility and effectiveness of this technology on a large scale.
Solar road experiments
- Wattway (France): In 2016, France inaugurated the first solar road in the commune of Tourouvre-au-Perche in Normandy. The kilometer-long road is equipped with solar slabs developed by Colas, a subsidiary of the Bouygues Group. However, the results of this experiment have been mixed. The slabs proved less effective than expected, due to their low inclination to the sun and the shading caused by vehicles. In addition, some slabs deteriorated prematurely due to traffic and weather conditions.
- SolaRoad (Netherlands): Inaugurated in 2014, SolaRoad is a 70-meter-long solar-powered bicycle path in Krommenie, the Netherlands. This pilot project, developed jointly by TNO, the province of Noord-Holland and other partners, has produced encouraging results. The track produced more energy than expected and demonstrated the feasibility of the technology in real-life conditions. Following the success of this project, other solar-powered cycle paths have been developed in the Netherlands.
- Solar Roadways (USA): This American project aims to develop modular solar slabs made of tempered glass, capable of withstanding vehicular traffic and generating electricity. In 2016, a 13.9 m² parking lot equipped with Solar Roadways tiles was inaugurated in Sandpoint, Idaho. Although the project has attracted a great deal of interest, questions remain as to the slabs’ durability, adhesion and cost of large-scale implementation.