Electric buses are gathering speed
The debate surrounding a possible ban of diesel vehicles has given electro-mobility in urban public transport a massive boost. Electric buses alone will not drive NOx emissions below the necessary threshold, however a switchover could make a significant contribution. In Germany and abroad, operators of pilot projects and even entire transport networks are running electric buses.
Berliner Verkehrsbetriebe (BVG) provides a perfect example of the challenges and opportunities involved in electro mobility in the most important market segment, namely large urban buses. BVG operates around 1,400 buses in the German capital, and its network is the largest in any German-speaking country. Since the summer of 2015 four electric buses, which are charged by wireless induction at the terminal, have been operating on the 204 city route from Bahnhof Zoologischer Garten to Bahnhof Südkreuz. The buses were procured in 2014 as part of a development project. The project ended in September 2016, although the buses are still operating at BVG’s expense. In late 2017 the supervisory board approved the procurement of 30 standard and 15 articulated buses. The contracting process has already begun.
Keen interest from manufacturers
The public transport company BVG is also exploring the market by testing electric buses from various manufacturers on its bus routes for a limited period, usually two weeks. Ten manufacturers have expressed their interest. Six vehicles have already been put into service on route 204.
However, the roads are not the only place where BVG conducts tests. It is also involved in research at the Mobility2Grid research campus where it is collaborating with other project partners. Research there includes developing and testing the bi-directional charging capability of vehicle batteries, i.e. their ability to recover energy when braking or travelling downhill. The research programme includes feasibility studies and technically evaluating charging infrastructures, charging concepts, fleet charging strategies, storage concepts and the integration of smart grids. Electro mobility represents much more than purchasing vehicles, hence the research group is also working on a bus depot electrification concept.
The first consideration is how to charge a vehicle. Unless it is equipped for wireless induction charging it requires a mains connection whose capacity by far exceeds that of a conventional socket.
Test buses are charged by night at a specially converted remote bus depot. Due to electric buses having a shorter range, bus routes have also had to be changed. “At the end of the research project I can say that operating electric buses works, providing the technical systems are in place“, was BVG director Sigrid Evelyn Nikutta’s initial assessment of operations on route 204.
Maastricht’s electrifying experience
In the Netherlands trolleybuses, which use pantographs to draw current, can be seen everywhere. In Maastricht, the capital of the province of Limburg, Arriva, a subsidiary of Deutsche Bahn which operates abroad, runs the public transport system. The plan is for public transport in Maastricht to be emissions-free from 2018/19, and the same target has been declared for the whole province by 2025/26.
44 buses in Maastricht are electrically charged not only by night, but also when they brake and travel downhill, and in the daytime at some intermediate stops. This must take place because their daily runs total up to 300 kilometres, whereas their battery range is currently only 150 kilometres. When it arrives at a stop a bus parks under a gantry and “docks” with its pantograph. After 28 minutes the batteries are fully charged again.
On board it is amazing how quiet an electric bus is. In conversation, the driver told me driving an electric bus was fun because it accelerates rapidly, and when it travels downhill or decelerates it becomes a challenge to try and recover as much energy as possible. If the driver doesn’t accelerate every wheel revolution charges the batteries, like a dynamo. However, starting and stopping was completely different to a diesel-engined bus, more like powering up a computer, he said. Anne Hettinga, CEO of Arriva Nederlands, says: “Changing over to electric buses means more than adopting a new technology. It means swapping systems. Everything is different.” Initially they kept some diesel-engined buses “just in case“, but these are gradually being removed to rural areas.
Arriva, a subsidiary of Deutsche Bahn that operates public transport in Europe outside Germany, would like the industry to build more comfortable buses for use in rural areas, among other locations. Guido Verhoefen, head of Marketing and Business Development at DB Regio Bus, hopes that German manufacturers will soon be able to supply vehicles in greater numbers and points to “unconventional“ manufacturers, from China for example, who are already able to deliver. DB Regio Bus which has 40 bus companies and holdings and a total of around 13,000 buses, of which 5,000 are the company’s own, is no small industry customer.
Main problem: vehicle range
For public transport companies the main problem is vehicle range, which currently is still well below diesel-engined buses and results in high infrastructure costs. Given the current charging infrastructure, vehicle range is inadequate for the needs of a company like DB Regio. Verhoefen: “Our routes are longer than those of urban buses, which operate in a tighter infrastructure. At present no independent infrastructure, i.e. one with charging points away from bus depots, exists which could solve the problem. DB Regio Bus would be glad to assist by offering its expertise, he added.
BVG, for instance, would like more efficient heating systems. Heating an urban bus is no trivial matter. During winter, although a bus interior need not be at living room temperature, fully opening the doors triggers a rapid exchange of air and is an extra load on the heating system. If the heating system is battery-assisted then during the cold months the vehicle range plummets, a problem that electric cars are also known to have. Manufacturers approach this problem in different ways. Some buses have a petrol-operated heater on board, which naturally causes emissions, although less so than a diesel-powered unit. Other companies factor the energy loss into their vehicle range calculations.
Standard interfaces are imperative
Both Berliner Verkehrsbetriebe (BVG) and DB Regio attach great importance to standardising infrastructure interfaces, for example the ideal positioning of charging sockets or pantographs. Vehicle, battery and charging systems must be standardised as they are on almost every type of internal combustion engine. According to Verhoefen, it was the task of policymakers to formulate these standards in laws, regulations and provisions. That was the only path to establishing a competitive market and contracting process.
Lastly, the costs remain a source of concern for all those involved. Electric buses are significantly more expensive than conventionally powered vehicles. As with cars, the reason has less to do with the systems used – in principle electric motors are
cheaper than a finely tuned internal combustion engine – than the fact that mass production is still a long way off. It is for the same reason that life cycle costs (LCC) are currently too high, of which a significant part is the especially complex infrastructure.
All the players in this scenario have it in their hands to let electro mobility achieve a breakthrough on the roads. In addition to the development of battery technology and the charging infrastructure and the will to rapidly reach mass production, another important element is demand. This is why in Germany a number of large operators have joined forces. BVG CEO Sigrid Nikutta: “In August 2016 Governing Mayor of Berlin Michael Müller and his counterpart from Hamburg, Olaf Scholz, signed a statement of intent on the future joint procurement of emissions-free buses by the public transport companies of their respective states (BVG, Hamburger Hochbahn and VHH).“
The three companies operate a combined fleet of close to 3,000 buses. Other major cities, including Munich and Cologne, have also signed up to the initiative. “By formulating common basic demands for mass production vehicles the aim is to remove unnecessary obstacles and encourage manufacturers to rapidly develop and make buses available that meet the market’s demands. Our joint message is this: the market is there, and we need buses that are ready and able to meet its demands“, said Nikutta.
Flexible purchase contracts
In addition to recently ordering electric buses the Berlin public transport company has formulated “flexible purchase contracts for diesel-engined buses“, said Nikutta. DB Regio Bus reports a similar strategy. According to the company, invitations to tender have been issued which, in addition to agreeing the procurement of conventional buses (mainly Euro 6 compliant), reserve an option for the duration of the contract to negotiate a changeover to electric buses”, said Verhoefen. Contract talks are about to begin, he added. However, “the transport contracts being signed now generally run over a period of ten years. It is likely therefore that not many electric buses will be circulating before 2027/28.” His company was currently looking around for pilot projects. No master plan for electro mobility existed as yet, he added.
Policymakers have already spelled out dates: At the ’Diesel Summit’ in late autumn 2017 Governing Mayor of Berlin Michael Müller announced that as of 2020 Berlin and Hamburg would issue no new contracts for buses with internal combustion engines. It is worth looking at that sentence again. Far from meaning that cities will be populated only by whirring electric buses as of 2020 it simply means that from that date onwards no more orders will be made for diesel-engined buses. Nor does it reveal how many orders for conventional buses are still being fulfilled.
Verhoefen points to Schleswig-Holstein, where the governing ’Jamaica coalition’ expressly encourages municipal authorities and regional associations to take measures promoting electro mobility. Some authorities wanted to specify electro mobility in their invitation to tender, said the marketing head of DB Regio Bus. Besides the political orientation of those involved the reason for that was wind energy, which was in plentiful supply.
An entire system is changing
According to Hettinga, the issue is not just about new power trains. Rather, an entire system is changing. The need for a new infrastructure best illustrates how for policymakers a considerable task to shape the future lies ahead of them. Standardisation is urgently required not just so that providers can use the same interfaces. It is the only way to compete in almost every market, assuming that they want to. Standardisation is also necessary because it is not always clear who is responsible for which part of the system. An example: in cases where municipal authorities issue an invitation to tender for a public rail transport contract they generally provide the infrastructure, i.e. the rail network. In the case of a bus contract until now this was the road network, which in principle is all that is needed for operating diesel-engined buses. With electric buses however, this is different because the responsibility of providing the charging infrastructure can be considered that of the municipal authority or of the contractor. In each case standardised interfaces are required, between a pantograph and charging point, for example. This is where operators are hoping for input from policymakers and manufacturers.