The road map to zero emissions


David Fowler reports on the second session, Chaired by Anthony Smith of Transport Focus, at yesterday's UK Bus Summit 2018. 

TfL managing director for surface transport Gareth Powell opened the day's second session by stressing the need for political leadership and the need for leaders to set ambitious clean air targets. The London mayor, Sadiq Khan, had done this and it was TfL's job to turn the goals into reality.

The new toxicity charge had been introduced over the congestion charge zone last October, affecting cars and HGVs/buses below the Euro 4 or IV standard respectively. From April next year, this regime will be replaced by the ultra low emission zone (ULEZ), introducing a charge for diesels below Euro 6 or VI in the congestion charge zone, operating 24 hours a day.

Currently consultation is under way on extending the ULEZ to the North and South Circular roads from 2021, and to uprate the minimum standard for heavy vehicles to Euro VI London-wide from 2020.

"There is a two to three year timeframe to move to better outcomes," Mr Powell said.

London's fleet was already one of the cleanest and newest in the UK and for the future only Euro VI hybrids would be added to the fleet. "Euro VI is exceptionally clean," he said.

TfL is "in the middle of a massive retrofit programme" to get all buses to Euro VI standards by 2020. 4,200 buses will be converted in two years in "a great example of partnership" between TfL, retrofitters, operators and buys manufacturers.

Buses operating in areas of worst air quality were being prioritised. On Putney High Street, one of the first two Low Emission Bus Zones, in 2016 there had been 1,248 hours when NOx emissions had been above legal limits. Since introducing retrofitted buses this had been reduced by 98%, through a combination of technology and bus priority measures.

In parallel, TfL is running trials with a significant number of zero emission buses, including hydrogen powered types, in an effort "to pump-prime the technology to show what we can do and to encourage everyone to adopt".

LowCVP managing director Andy Eastlake said that though the Government had published numerous plans for improving air quality and the environment over the last year these had been vague.

However, the Low CVP and its partners and members (including car makers, transport authorities, universities and test organisations) had been developing a strategy and targets to bring about cleaner air, lower energy consumption and a lower carbon footprint.

This had to be pragmatic, on the grounds that the whole vehicle fleet could not be replaced. But it would take in clean vehicles, efficient vehicles and zero tailpipe emission capability, with robust measurement and evidence and dissemination of best practice.

He said: "What you don't want is an array of different standards," and that the Low CVP would like to see common standards for Clean Air Zones in England, Low Emission Zones in Scotland and the ULEZ in London.

He suggested ambitious targets for consideration, which could include supporting widespread introduction of CAZs/LEZs; every new bus in 2020 to be low emissions specification; 10% of buses in 2020 to be fully electric; and every new bus in 2025 to be ultra-low emission spec.

As communities adopted CAZs and LEZs, it was "an opportunity to demonstrate the benefits of the clean bus" as well as highlighting other benefits for energy, efficiency, and congestion. Currently the bus sector was best prepared to meet the requirements, it was moving fastest towards zero emissions, and there was funding to support this. But new cars were also improving very fast and closing the gap, so there was "a narrow window to discourage cars from city centres".

First Bus managing director Giles Fearnley told delegates: "It's not just about the bus itself. If we are really going to achieve ambitions for zero emissions isn't it about filling those buses with more and more customers?"

Buses were often characterised as yesterday's transport – "but do not be fooled: we are on the way back. I am confident we have a very strong future."

In Bristol, first was seeing its fifth year of patronage growth, and the same thing was happening in many other areas of operation.

He continued: "We are seeing a revolution in ticketing and how we interact with customers."

Customers were extremely enthusiastic about contactless ticketing. In Aberdeen, eight months after contactless was introduced, 30% of passengers were using it and over 50% of transactions were contactless or via mobile phone. In Cornwall 20-30% were paying by contactless after 10 weeks.

Multioperator tickets were becoming more common. "We need to be open to discussions about ticketing," he said. "No more should we have segregation between operators."

First was "champing at the bit to invest in high priority, high frequency corridors," he said.

For bus operators there must be "no more going through the motions of partnership and no more second class delivery."

Calling on local authorities to give more priority to partnerships, he said "we either deliver together or we deliver nothing". First was keen to invest. He urged local authorities "who don't yet get it" to come on board.

Optare commercial director Robert Drewery looked at the barriers to the wider adoption of electric buses in the fleet. "It's not really a technical challenge but a policy challenge," he said.

Currently there are 250 electric buses in UK service and the fleet had doubled in the last three years, though it still only made up 0.5% of the total. These buses were providing daily service, with availability better than their diesel equivalent.

"We as an industry have to develop a zero emission future if the bus is to have a place," he said. He did not believe that the solution would be a modern trolley bus or hydrogen power: because of advances in battery technology it would be battery electric.

There were two barriers, he added: range and cost. On range he said Optare "had set a target of 200 miles on a single charge to end the debate about range."

Currently, a battery electric bus needed 130% of its stored capacity to cover 200 miles. The 30% gap would be addressed through increased battery energy density, improved energy efficiency and reduced base vehicle weight.

Energy density had increased by 300% in the last five years and the cost per kWh had decreased, and the trend was expected to continue. New battery chemistry such as lithium-sulphur was expected to increase energy density by over 20% by 2020. "I don't see energy density being an issue for electric buses by 2025," he said. "Opportunity charging will not be necessary."

In addition moving from a conventional gearbox/axle drivetrain to hub motors would improve efficiency and increase range by 8-10%. Second generation electric heating systems would yield another 5%, and weight reduction another 4%.

This left cost as the biggest barrier. Currently electric buses carry a 75-100% premium over the cost of a diesel. 75% of the premium is due to the battery cost.

Battery costs per kWh halved between 2010 and 2015 and are predicted to reach €100/kWh by 2025. This reduces the premium to 40%, ignoring driveline savings and cost savings from a lightweight platform. Partnerships with battery providers and battery leasing could reduce costs further.

Mr Drewery said the experience with hybrid buses demonstrated a virtuous circle on cost and development. Operators would not invest in zero emission buses without an incentive, and no demand would slow investment by bus manufacturers. Support is mostly limited to London.

To start the virtuous circle, he argued that the bus industry needed to offer policymakers a lever to secure urban patronage – and it must lobby policymakers to give a commitment to drive the pace of adoption.