In December of 2016, France was poised to be the world's premier innovator in renewable energy with the unveiling of the first solar-panel highway, and hopes were high. The French Ministry of the Environment even called it "unprecedented". However, a mere three years later and the very ambitious French energy project is now being referred to as a "colossal failure."

The solar road, known as Wattway, was a project designed, engineered and maintained by the Colas Group, a civil engineering company that specializes in roadways and railways. The company has since lost all motivation to further pursue the renewable energy highway.

Wattway's managing director Etienne Gaudin had this to say in an interview with Le Monde. "Our system is not mature on long-distance traffic," he said. The company plans to focus on creating electricity on a much smaller scale, such as enough energy to power CCTV cameras and to light bus stops.

Although the solar highway was a novel idea, it seems as though a lack of foresight was its eventual demise. Wattway was initially estimated to be able to generate 300,000 kWh per year, but even at its best only half of that energy was generated within the first year. By 2018, that number dropped to less than 80,000 and as of January, 2019 the numbers were even lower, amounting to just under 40,000 kWh.

Another oversight that proved detrimental to Wattway was thunderstorms and the resulting leaves which after falling, blocked sunlight and created a thin layer of mold that drastically reduced energy storage. Not to mention, the road was constructed in a small town in Normandy, that on average, receives strong sunshine only 44 days a year.

In May of last year, almost 10 percent of Wattway had to be completely demolished due to the heavy weight of traffic, specifically tractors. Another oversight in the design, as the panels were placed in the carpool lane.

Not only was the solar panel roadway an engineering disaster, it was also a financial nightmare. The five-million-euro project was expected to generate 10,500 euros per year, but it instead produced 4,550 euros in 2017, only 3,100 euros the following year, and for the first quarter of 2019, it received a very disappointing 1,450 euros.

Marc Jedliczka, vice president of the Network for Energy Transition, was not happy with the overall planning and execution of the project. "The technical and economic elements of the project were not sufficiently understood." he said, "It is a total absurdity to innovate at the expense of solutions that already exist and are much more profitable, such as photovoltaics on roofs."

The Wattway company still has about 45 more similar projects around the world, albeit, most are on a much smaller scale.