Range anxiety is still one of the biggest problems with electric cars. Despite improvements in battery life and charging times, would-be converts are still put off by the thought of being stranded somewhere in the countryside, miles from the nearest smart charging hub.
But what if your car could charge while it was driving? That’s the goal of an ambitious project in Sweden, which unveiled its first stretch of electrified road today.
About 1.2 miles of electric rail has been embedded in the road near Stockholm – with energy being transferred from two tracks of rail in the road via a moveable arm attached to the bottom of a vehicle. It’s like a tram with the power lines on the bottom instead of the top, or, as the Guardian points out, a life-sized Scalextric track.
“One of the most important issues of our time is the question of how to make fossil-free road transportation a reality,” said Hans Säll, chairman of the eRoadArlanda consortium, which is running the project. “We now have a solution that will make this possible, which is amazing. Sweden is at the cutting edge of this technology, which we now hope to introduce in other areas of the country and the world.”
The road is divided into 50-metre sections, with an individual section receiving power from the grid only when a vehicle is above it for safety reasons. “There is no electricity on the surface,” said Säll. “There are two tracks, just like an outlet in the wall. Five or six centimetres down is where the electricity is. But if you flood the road with salt water then we have found that the electricity level at the surface is just one volt. You could walk on it barefoot.”
The system, which disconnects when a vehicle stops, is also able to calculate each vehicle’s energy consumption, and can therefore bill the user directly.
It’s hoped that this kind of dynamic charging will mean that vehicle batteries will be able to be made smaller, and therefore cheaper. “If we electrify 20,000km of highways that will definitely be enough,” Säll said. “The distance between two highways is never more than 45km and electric cars can already travel that distance without needing to be recharged. Some believe it would be enough to electrify 5,000km.”
The Swedish government is going all-in on the technology as part of its ambitious plans to achieve full fossil-fuel independence by 2030. To do that, the Scandinavian country needs to cut 70% of its emissions from the transport sector, and has drafted a national map for the future expansion of these electrified roads.
Another approach
Other companies are working on inductive charging, which would have the same effect as the electric roads being installed in Sweden, but with the benefit of the charging being wireless. Chipmaker Qualcomm has built a 100-metre test track near Paris to test its technology, and has been able to charge vehicles at 20kW as they drive along it at 60mph, even when two cars are travelling in opposite directions.
It works in a similar way to electric toothbrushes, or one of the new wave of smartphones with inductive charging. Coils embedded in the road transmit power to coils in the car, and research suggests that only a quarter of a 1km stretch would need to be fitted for an electric vehicle to drive along it without draining its batteries.
In Israel, ElectRoad has been testing a similar system, and wants to build it along a section of bus route in Tel Aviv. However, although inductive charging is neater than the ‘Scalextric’ approach, it’s more expensive to install, and is unlikely to be feasible outside major cities. However, as MIT Technology Review points out, it could make sense for public transport, which runs on fixed routes at predictable times.
Are electric roads actually necessary?
However, before they go digging up thousands of miles of highways to install electric cables, the Swedish government might want to reassess the latest battery technology. Lithium-ion batteries are constantly improving, with new vehicles offering greater and greater range.
There are also new developments in hydrogen cars, and breakthroughs in supercapacitor technology which could make them a viable replacement for lithium-ion batteries. It’s possible that electric roads are a solution to a problem that may not exist any more.