Inductive technology in concrete roads could charge EVs
The construction of roads that use inductive technology to charge electric vehicles (EV) as they travel could overcome a lack of charging points across the country.
The suggestion from Britpave (The British Cementitious Paving Association) claimed that concrete would be the most suitable material for the roads’ construction.
Drivers of EVs currently suffer from a phenomenon known as “range anxiety” because of concerns that the vehicles won’t have enough power to reach their destination on roads where charging points are often scarce. Surveys carried out by motoring magazines have found that EVs appear to fall short of manufacturers’ claims on how far you can travel before charging the battery by as much as 15%.
Meanwhile, data company Emu Analytics has claimed there are only 16,500 charging points in the whole of the UK. With an estimated one million new EVs coming onto UK roads within the next two years, there needs to be a network of 100,000 charging points.
Joe Quirke, Britpave chairman said: “Faced with the lack of trust in manufacturer claims and the lack of an adequate charging network it is little wonder that ‘range anxiety’ is a barrier to more people buying EVs. A new approach is required and increasingly the potential of concrete ‘eRoads’ that inductively charge EVs as they travel are being examined.”
How does inductive charging work?
Inductive charging is where the EV battery is charged without the need to plug the vehicle into a charging point. The process is wireless and can be done whilst the EV is on the move or stationary. If the vehicle is moving the process is referred to ‘dynamic charging’.
Quirke highlighted several projects to research and develop eRoads, including one by Flanders Make, the Belgium-based manufacturing industry research centre, which has tested the installation and use of inductive charging systems in concrete and asphalt roads.
Primary coil modules were installed to create a magnetic field within the road surface. The magnetic field creates an electric current in a secondary coil placed on the vehicle’s undercarriage which feeds the charge to the vehicle’s batteries. The research found that energy efficiencies of 90% were achievable, only 4% less than using a charging point.
The findings of the research had been used for the construction of 200Kw bus charging stations in Bruges, Belgium, and Braunschwieg, Germany. In Bruges, precast concrete bus stops take 15 minutes to wirelessly charge parked buses after every 12km travel loop.
In France, the recent FABRIC project studied dynamic conductivity. A wireless electric vehicle charging system, developed by Qualcomm Technologies, was installed in a 100m test track at Versailles, Paris. The system successfully charged two Renault Kangoos EV with 20Kw at speeds of over 62mph.
Road surface durability
Britpave emphasised the importance of the road surface durability for the successful operation of the installed module. Quirke said: “What is being underlined by the research is the need for the road surface to have long-term durability and minimum maintenance. Both are inherent characteristics of concrete roads.
“A further benefit of concrete roads for the installation wireless modules is that in hot summer temperatures they, unlike asphalt, do not melt. Such melting could dislodge and compromise the positioned embedded wireless system.”
Britpave added that it may be possible to make the concrete road itself conductive.
Australian-based Talga Resources is mixing graphene into concrete to make it conductive and so charge an EV whilst it is driving.
In Germany, Magment – magnetizable concrete materials – are being developed by using magnetic ferrite particles as aggregates. Magment concrete consists of 87 per cent magnetisable aggregates which is waste product from the manufacture of ceramic ferrites and the recycling of electronic scrap. It allows energy to flow into a coil to inductivity charge vehicles as they pass. The proposal is to cast (either precast or insitu) concrete ready-to-connect coil modules that contain all the required wiring including optional sensors for integration into road construction.
“Durability and minimum maintenance are key for future eRoads. This is especially so as the vehicles, particular heavy goods vehicles, will be travelling on the same path in order to charge. The road surface must, therefore, not prematurely deflect or rut. Concrete roads have a performance life of 50-60 years and are so fully able to provide the required long-term durability,” said Quirke.