Wattway solar road : an economic impasse
The French Ministry of Environment funded and inaugurated 1 km of the Wattway solar road in Normandy. If the concept is a world premiere, it is still looking for economic and environmental legitimacy.
The Wattway solar road: an inauguration with great pomp, but an uncertain economic model
One kilometer long on 2,8 meters wide: the first large-scale project of the Wattway solar road has been inaugurated in Tourouvre (Orne) on Thursday, December 22nd by Ségolène Royal, Minister of the Environment.
In the next four years, this technology will be installed on a section of the main road 164 in Brittany, on a rest area in Marzan (Morbihan), and on the main road 165 as well as in the Great seaport of Marseille (Bouches du Rhône).
The need to cover cities electricity demand
Made in the SNA factory in Tourouvre, these paving stones consist of photovoltaic cells in polycristallin silicon which are 15 cm wide. These cells are coated with a resin containing glass aggregates able to bear the passage of vehicles, in particular lorries. With this product, Wattway intends to cover local needs in electricity (such as lighting or the refill of electric cars).
In Tourouvre, the 2.800 m2 of paving stones should produce 280 MWh per year, injected on the distribution network, which means 100 kWh/m2. A lower performance than classic roof solar panels, whose yield is 137 kWh/m2 on average in France. Traffic, the slope of the panels which is not optimal and the dirtying of the cells will indeed reduce their performance.
A question of priority
As all innovations, Wattway’ one does not escape the cost issue. 2.800 m2 in Tourouvre have costed 5 million euros to the Ministry of Environment. The Colas group works to propose the solar road at 6€/W. Many wonder about the interest of such a product, when solar energy on roof costs just about 1,3 €/W.