A 2km stretch of road in Sweden has been embedded with an electrified rail as part of the latest trial by a consortium hoping to roll the technology out across the country.
The eRoadArlanda project sees DC energy transferred from a rail in the road to vehicles passing above using a movable arm. Sections of rail, which are connected to the grid, power up individually as vehicles travel over them. The arm detects the location of the rail and remains in contact as long as the vehicle is above.
When overtaking, the arm automatically retracts. The system is also able to calculate energy consumption so that customers can be billed on a pay-as-you-go basis. It is expected to operate only on primary roads, with vehicles relying on their batteries once they exit on to arterial routes.
“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 and business development director a Swedish construction company NCC.
“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.”
According to the consortium, up to one kilometre of electrified rail can be installed per hour and interruptions to existing infrastructure can be minimised. Due to the short distance between the vehicle and contact point, a conductive feed from below works for all types of transport, including both cars and larger vehicles, such as buses and trucks.
The trial is taking place on public road 893 between the Arlanda Cargo Terminal and the Rosersberg logistics area outside Stockholm. Parties to the extensive consortium include Elways, NCC, PostNord, ABT-bolagen, Vattenfall, DAF, KTH, Kilenkrysset, VTI, E-traction, GCT, KTH, Bilprovningen, Airport City Stockholm, Sigtuna Municipality, Swedavia, Arlanda Stad Holding, TraningPartner, FirstHotel, Frost Produktion, SMM Dulevo and Sandströms Elfirma.
“It is important to break new ground when it comes to climate-smart road transport,” said Lena Erixon, director general of the Swedish Transport Administration. “That’s why the Swedish Transport Administration supports innovative development projects that contribute to long-term, sustainable solutions.”
We had that years ago…we called them “trams”
Sorry to question that, but no, trams did not use powered rails in the road. The first trams were horse-drawn. Then steam. Then battery electric and cable-pulled. Then, after Croydon, they were supplied by overhead cable and sprung contacts, just like the trolley buses that followed. If only the trolley bus principle had been updated and improved, we might not be in the mess we are now.
See for more, if interested.
i would understand wireless charging built in to the roads but not live rails. think this is a case of reinventing the wheel. we know the millions that this tech takes in upkeep as we have above trails.
what happens when its full of grit? what happens if fuel gets in? what happens when the road floods?
wireless charging is a tech available now, figure how to use wireless high current charging and maybe this might work …. possibly ….. maybe.
Does it work in the rain? What happens when you’ve got 5cm of snow on the road? Or debris? I can just imagine stupid kids putting sticks in the way and sitting by the road watching the carnage. Wireless charging is the way to go.
The video above shows several vehicles operating on the system in the snow.
Nice idea, but, doesn’t Sweden have a lot of snow?
As is often the case, more questions than answers. I would like to see a follow up article on this, with answers to Adam’s questions, and more on how the pick-up unit on the vehicle is controlled. What happens if the batteries go flat? It is an interesting concept that at present is seemingly viable until wireless charging becomes more efficient.
It’s a good job we have thoughtful contributors to these comments so the designers can be fully informed and consider the risks involved in a new product.
Come now sceptics, this is a power rail flush with the surface of the road (nowhere to trap grit); that can transfer high currents at high efficiency (unlike inductive coupling); that the vehicle tracks beneath it automatically (no need for guide rails); and that only turns on beneath the vehicle (when away from pedestrians). It’s worth doing a trial.
@Adam Smith
Was thinking the same. Induction charging system embedded in the road might be better. Electric rails are sensitive for. a wide variety of problems:
wear from contact
ice
snow
dirt
short circuiting
But okay, that the article doesn’t mention these issues doesn’t mean they aren’t being addressed.
Several surface contact systems were tried out at beginning of 20th century on tramways. One typical one was the Loraine system used in Tettenhall in Wolverhampton to avoid disfiguring the posh area with overhead wires. The horses were not impressed when the studs failed to de energise after the car had passed over. It did not last long
Is this the system displayed at Crich tramway museum in Derbyshire ?
Our benighted government here recently and foolishly elected to cancel electrification of credible rail projects on alleged grounds of cost. (For which read complete incompetence by the sponsors and government and a belief in exotic unproven alternatives. I wonder how electrifying roads will be financed together with ongoing maintenance, security of supply, failure mode and recovery ,charge out rates for use and a host of other considerations. Other electrified road projects seem to be focused on overhead power supply options. The same counter arguments apply.
Can the pointless pursuit of low Co2 motive systems get any more contrived that this?
I think we need to secure the electricity supply in the UK before we expand the demand to this level.
I like the concept and remember reading science fiction, possibly ACC, where all major roads had an energy supply and the vehicle travelled along side roads on battery, that was around 40 years ago, it’s always good to see science fiction becoming science fact through the application of Engineering.
So, who pays for the electricity they use while drawing power from this system?
I believe the article actually says – the customer does. Didn’t you read it?
So when are we going to get solar film embedded on the car roof and bonnet? – that seems a lot better idea, except maybe for the Nordic countries where there is an abundance of cloud
It can be very sunny in Nordic countries; I got sunburned in Helsinki once!
Let’s face it – we could design hybrid systems that would be MUCH more efficient, convenient, don’t require complex infrastructures, cheaper and far more sustainable than this idea.
I read somewhere that the conductors are underground where the design protects them from the elements. I can’t imagine how they do this but let’s give them credit for being inventive engineers, good at imagining and solving problems like that. I think its amazing that they can lay a kilometre per day. This system would be a challenge to install in Australia where the major centres of population are 1000km apart but this might be where the greatest rewards are as well. A customer beside me in a service station paid AUD1400 for fuel the other day to fill his semi trailer tank. Perhaps the people who pay for the track for the good of society will pay for the electricity. I think it would be better to electrify the railway and have trains of several hundred containers for the long haul then electric trucks for local delivery. In the long term it will save a lot on batteries. We only have to find enough renewable power. Panels on every roof.
As an interesting aside most new factories in Australia come with lightweight, cheap roofs that can’t carry the weight of solar panels. How is that for forward looking governance?
The article speaks of A rail and pickup, where is the return circuit? With trams we had the running rails for the return.
What about safety? What is the voltage? What happens when someone touches the live rails?
I wonder why they aren’t using induction charging? there wouldn’t be any contact between vehicle & road & no slots to fill with dirt and water.
Bazzer
Can’t see this working here in England, Staffs especially,………….. too many potholes to negotiate whilst trying to lay the rail !
From the video, it appears that there must be some communication between the vehicle and the track, because they mention calculating the energy taken and billing the user. This suggests that the supply is a lot more sophisticated than exposed power rails – perhaps the communication is required to turn on the power. This would prevent injury to life, and protect the system from debris.
My uncertaintly is with the reliability and maintenence of the vehicle’s power take-off system – it seems open to a lot of wear and tear. Perhaps it also only extends when it senses the power rail pelow it?
The idea of charging at intervals during the journey when you are on a main road seems quite nice: as long as your usual journeys take you on a main road!