From 2017, certain stretches of the famous American Route 66 will be paved with a revolutionary photovoltaic asphalt capable of powering buildings, road signs and electric vehicles.
In Italy we can boast the Autostrada del Sole — that is, the A1 Milan–Naples motorway. Abroad, however, the first solar motorways are emerging. This is more than a merely lexical distinction: in the first case we are talking about a traditional, busy and anything but smart transport artery, while in the second we find ourselves in the presence of sustainable infrastructures dedicated, yes, to vehicle traffic, but at the same time designed for the production of clean energy. Two very different worlds.
The first solar motorway was inaugurated in 2014 in the Netherlands and consists of a cycle path fitted with a special surface capable of producing more than 9,000 kWh per year. By using the road surface as a photovoltaic installation, it is possible to power lighting, road signs and all electrical and electronic equipment along the road — including vehicles — at extremely low cost. The project, known as SolaRoad, is based on the use of solar panel modules covered with a thick layer of tempered glass that protects the radiation-sensitive cells.
Following the example of the Dutch SolaRoad, American inventor couple Julie and Scott Brusaw have devised an "asphalt" containing photovoltaic cells, capable of capturing solar radiation and converting it into electricity. Solar Roadways, as these novel infrastructures are called, have the potential to revolutionise mobility across the planet. It is no coincidence that the project raised more than two million dollars in funding in under a month for the transition from the design phase to the experimental phase, driven by the consideration that, if the 260,000 kilometres of American highways were ideally fitted with the solar tiles, it would be possible to generate three times the country's current electricity consumption. In addition, electric vehicles, including lorries, thanks to inductive charging technology, would travel with an extended range; a condition that would encourage their uptake while easing the current shortcomings of the rapid-charging network.
The first tests focused on safety and, above all, on the wear resistance of the photovoltaic surface are encouraging, to the point that grip is reported to be no inferior to that of traditional bitumen and the structure is said to be capable of bearing the weight of an articulated lorry. Safety that, particularly in areas with harsh climates, would be further enhanced by the possibility of heating the road surface, preventing ice formation and promoting snow melt during the winter months. The first applications of the new technology will be limited to the paving of rest areas, before extending — thanks to an agreement between the state of Missouri and Solar Roadways, the American company that will install the road solar panels — to short stretches of Route 66, the most famous motorway in America. The operational phase is set for 2017.