Electric roads are revolutionising transport by supplying electricity directly to vehicles as they drive. This is one of the most promising options for fostering the use of sustainable forms of transport that reduce carbon-dioxide emissions while being efficient.
Electric roads would combat some of the disadvantages associated with electric mobility. When people are thinking about buying an electric car, they worry about things such as the shortage of charging stations, range, charging times, production costs and the environmental impact of batteries. Electric roads would enable us to reduce these drawbacks, including the size of batteries. A study from Chalmers University found that electric roads could reduce battery size by up to 70%, by enabling cars to charge while they are being driven.
How electric roads work
There are various technical requirements for both the vehicles and the infrastructure for this solution to work. Of course, you can't use just any road or just any electric vehicle.
The idea behind electric roads is similar to the way that trains work. Electric vehicles must have an articulated arm - as on trams and underground and mainline trains - which deploys when driving to connect to a catenary that provides electricity. This powers the engine without consuming energy from the battery and can even recharge the battery.
Other options are being developed to make electric roads more versatile and expand their use. For example, rails can be used for the electrical connection between the vehicle and the road. Induction systems are also being developed using coils installed under the road surface, in a similar way to the procedure for charging mobile phones by induction.
However, it is not feasible to electrify every road with any of these systems. One solution to this is to use hybrid vehicles that use fuel when necessary. Another option being considered is the design of roads that are 50% electric, in intermittent sections, so that vehicles can charge their batteries while driving.
The Swedish model
Electric roads are already a reality in Sweden. A first stretch was opened in 2018, between Stockholm Airport and the Roserberg logistics area, with a further section being developed on the island of Visby in 2020. Work is currently underway on an electric road between the Hallsberg and Örebro logistics hubs. Sweden expects to have a network of 3,000 km of electric roads by 2045.
This project is primarily aimed at electric freight vehicles, but private users could also benefit. Work is also being done with companies in other countries, including Germany and France, to assess the feasibility of creating a much more extensive network of electric roads.
Electric roads to foster electric vehicles
Higher fuel prices and increased awareness of climate change have made more and more people choose to invest in electric vehicles in recent years. These vehicles have many advantages:
- Low environmental impact: producing electric cars generates more pollution than producing a conventional vehicle. However, this is offset by the lack of CO2 emissions during the vehicle's useful life. This makes electric vehicles much more sustainable overall.
- Greater energy efficiency: electric vehicles are more efficient at using energy than petrol or diesel vehicles. In other words, they can travel further with the same energy because they waste less.
- Lower maintenance and usage costs: electric vehicles have fewer mechanical components and do not need oil changes or other adjustments, meaning they have less economic impact on the day-to-day lives of their owners.
And while they also have a number of drawbacks, these would, fortunately, be reduced by an expansion of electric roads:
- Limited autonomy: although batteries are lasting longer, they have nothing like the range of internal combustion engines. Electric roads would guarantee that electric vehicles could be driven without having to stop to recharge.
- Charging infrastructure: although the availability of efficient charging stations for electric vehicles is continually increasing, they are still not as prevalent as petrol stations.
- The environmental impact of batteries: the lithium-ion batteries used in electric vehicles have extremely high environmental impact, because of their production and the difficulties of their recycling.
- Initial cost and availability: although electric vehicles are becoming increasingly accessible with increasing supply and demand and production costs coming down, they are still more expensive than internal-combustion vehicles. Fortunately, electric roads could reduce the size of the battery needed, which would reduce their costs and, above all, their environmental impact.