Pantograph-based electric opportunity charging made its UK debut last week as the Volvo 7900e entered service in Manchester. Like its range, the bus’ potential is almost endless, says the builder
Electric was go for Volvo last Wednesday (20 September) when the 7900e made its UK passenger-carrying debut on a day that also marked the first use in anger here of opportunity charging via pantograph.
Operated by First on behalf of Transport for Greater Manchester (TfGM), the 7900e was presented to Mayor Andy Burnham two days later.
Volvo calls the moment highly significant. After lots of talking, here is proof that its OppCharge concept will deliver a zero-emission, unlimited range solution for urban mobility.
The demonstrator will stay with First for around two months. It is being used on one of three fare-free Metroshuttle services in the city centre, charging for a few minutes when needed in Shudehill interchange.
Although controlled testing has proved OppCharge’s worth, Volvo Bus is keen now to obtain real-world experience of it, and it has a number of further demonstrations agreed for the 7900e.
After Manchester, the bus will move first to Heathrow Airport. Meanwhile, the first production 7900es for the UK are on schedule to enter service with Transdev Blazefield in early 2018.
Part of ‘a turnkey solution’
The 7900e forms part of what Volvo calls a turnkey solution for zero emission urban operation; that is, it’s part of a comprehensive operational package delivered by Volvo and its partners.
The manufacturer continues to promote the potential for OppCharge to work with vehicles such as delivery vans and refuse trucks when it is not required for buses, and the Manchester project has seen Volvo liaise closely with many other stakeholders.
“Going from being a vehicle manufacturer to a complete service provider is a big jump, but in partnership with ABB we have invested a lot in OppCharge, and it is part of a package that is attractive to operators and local authorities (LAs),” says City Mobility Manager Adrian Felton.
In controlled circumstances, around three minutes’ charging has given the 7900e up to 20 miles’ range. In real-world operation that has the potential to vary considerably, and so Volvo continues its work to increase the rate of energy transfer, reducing charging duration and growing range.
The 7900e can also be charged overnight in depots, and Adrian believes that opportunity and depot charging will complement each other.
“Like the arguments for parallel and series hybrid packages, the market will support both, but providing sufficient charging capacity in a large depot will be difficult. In those cases, an element of opportunity charging will be required.”
The electric handshake
Developed with ABB, OppCharge is simple in operation yet highly advanced in functionality.
When the 7900e arrives at Shudehill, it and the OppCharge unit carry out what Adrian refers to as an “electric handshake.”
They communicate via wi-fi to ensure that the correct amount of charge is transferred. All data is recorded, making billing simple when more than one operator is involved.
OppCharge infrastructure has a life of around 30 years, says Volvo, allowing its costs to be spread over multiple vehicle generations.
Add that to the infrastructure’s potential other uses, electric buses’ lower energy costs than diesels’ and their obvious absence from upgrading projects that may be necessary for diesels to meet future emission standards, and the economics become clearer.
LA engagement is key
“Opportunity charging is a better use of public money than depot charging, but if it is to be rolled out on a wide scale, engagement with LAs is a must,” says Adrian.
Encouragingly, many LAs are already warming to the idea. Like TfGM, they are coming to understand the benefits that opportunity charging can bring to urban air quality.
It’s also important to focus on more than just the initial costs, adds Volvo Bus MD Nick Page. When the numbers are crunched for whole package TCO, vehicle price forms a comparatively small part of it. But if zero-emission is to become even more attractive, BSOG payments must be addressed.
“BSOG negatively impacts electric buses,” says Adrian. “At the moment they are eligible solely for the 6p/km low carbon uplift and not the base rate. We are lobbying hard for change.”
That work will go on, but as shown in Manchester last week, the 7900e is part of a package that is here and deliverable now.
“The move towards zero emission is clear,” says Adrian. He points out that on some days, the UK generates over 50% of its electricity from renewable sources, and that as part of the 7900e offering, buses can be powered by certified green energy.
“There is a net greenhouse gas saving of around two-thirds for a 7900e over a comparable Euro 5 diesel, and the Manchester demonstration is just the first of a concept that we believe will grow massively in the future.”
