The power of electromobility

Explore • Pulse #2 • 6 min
By Richard Venturi

Electric buses hold the potential to spark a modal shift away from personal automobiles in cities and towns across the globe, lending them great promise in reshaping mass transit in our increasingly urbanised world.

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Clean air pioneer

3 min

At the end of October 2017, the UN’s World Meteorological Organisation (WMO) released figures that showed that the concentration of atmospheric CO2 had reached 403.3 parts per million in 2016, a level not seen since the Pliocene age some 3 million years ago, when sea levels were 25 meters higher than today (Source). Given this and given the 2015 Paris Agreement’s ambitious goal of keeping global warming well within 2°C by 2100, the push to green the economy by developing alternative energy sources is now well underway.

The transport industry has a pivotal role to play in this. According to the EU, the sector, which includes cars, trucks, aviation and international shipping, contributed just under 26% of total GHG (greenhouse gas) emissions of the 28 member countries (Source).  And when it comes to cities, buses are at the heart of the way mass transit is being made more sustainable.

While buses represent only a small fraction of the pollution stemming from transport, their electrification can be particularly effective in reducing emissions and noise pollution in dense urban areas, both of which are growing rapidly across the globe. And unlike rail systems – be they trams, metros or commuter trains – buses require relatively little in the way of infrastructure, meaning networks can be up and running quickly.


China exemplifies this well. More than 350,000 electric buses are already in service in the country, and the south-eastern city of Shenzhen has become the first city in the world to go completely electric, with more than 16,000 buses on the streets.

In the West, Northern Europe has led the way in the use of biofuels for mass transit – with Sweden being the pioneer – and is now moving towards electric buses, with the rest of Europe and North America now following in its path.

This trend is likely to intensify for several reasons. One, public opinion, the media and politicians are pushing industry to follow through on the energy transition.

Two, battery technology is advancing rapidly, making electric buses more and more economically viable.

A third reason is down to the actual supply of battery-electric buses (BEBs). Manufacturers have developed their offer of electric buses extensively over the last two years. BYB and Volvo are just two examples of auto manufacturers banking on BEBs, with both unveiling new models in 2017. Volkswagen is also onboard, announcing last year it will invest 1.4 billion (€) in developing electric trucks and buses.

The fourth driver is industry standards. The European Committee for Standardization (CEN), the European Committee for Electrotechnical Standardization (CENELEC) and other bodies such as the International Organization for Standardization (ISO) are working to develop European and international standards with respect to charging, which are set to come in place over the next two years. This will level the playing field for manufacturers and operators and further spur market growth.


The Gothenburg Västtrafik network (Sweden) uses renewable energies to power 65% of its 390,000 passenger- kilometres covered every day (see Pulse #1).

Los Angeles

In 2010, the Foothill Transit network in the suburbs of Los Angeles, was the first American network to start using a fast-charging electric bus.

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What alternatives to conventional fuels?

2 min

On top of all of this, more and more cities are lining up to transition their bus fleets to BEBs. In October 2017, within the frame of C40 (Cities Climate Leadership Group) mayors from a dozen global cities, including London, Paris, Los Angeles and Mexico City, signed the Fossil-Fuel-Free Streets Declaration, pledging to procure zero-emission buses from 2025 and  “ensure a major area of (their cities are) zero emission by 2030”.


For the time being, BEBs cost twice as much as diesel buses. In effect, the excess expense today comes from the high prices of batteries – whether it’s the initial investment or the cost of replacing them (although public transport operators can usually benefit from rental opportunities from manufacturers, if buying the batteries proves too costly). However, prices of batteries have plummeted up to 90% in the last decade and are expected to continue to fall, with projections indicating BEBs will become commercially viable between 2020 and 2025 (Source).

Though urban bus fleets have yet to be replaced by electric buses, it is important transit authorities adopt a transition period and carry out trials. This will help ensure the energy transition is being carried out in line with the different environmental guidelines and targets. It will also enable authorities to take into account the local expectations, contexts and challenges by creating models and evaluating the technical and economic impacts.Moreover, this approach will enable operators to provide the best possible quality and deliver the optimum cost in the long run.

Recharging the batteries efficiently is the key to running successful trials. There are two ways this can be achieved. The first is charging along the line. This is done by fast charge, i.e. when the bus stops, a pantographic system connects to an overhead fast-charger for a few seconds to a few minutes. This provides a large enough charge for the vehicle to continue until the next charge. This can either be at every station, every few stations or at the end of the line. Helsinki, Finland, currently has several fast-charging BEBs in service.

The second charging solution takes place by plugging during 6 to 8 hours, when the bus is at the depot. For BEBs, this consists of an overnight charge. Of course, the type of solution opted for depends on factors such as the topology of the route, the distance between stops, climatic conditions, time spent at stops and the number of passengers.


Replacing fleets of diesel buses will certainly help unclog congested cities by reducing GHG emissions as well as fine particules and nitric oxide. But their ability to drive down emissions is much greater when the whole system is taken into account. In other words, quiet cutting-edge BEBs can very likely foster a modal shift, getting people to leave their personal vehicles at home. And this is where the significant impact will be.

According to calculations by the World Bank, if buses carrying 150,000 passengers per day on a simulated 30-km transit corridor were to shift to 100% electric, annual emissions would be cut by 27%. However, if 10% of passengers have made a modal shift – i.e. they leave their cars at home – this would be equal to a full 48% drop in emissions.

China clearly appears to be leading the way when it comes to this shift. As mentioned before, the city of Shenzen is a case in point, with its more than 16,000 fully-electric buses. Taking the long view, the transition to alternative energies in transport is more than simply a change in motorisation – it’s the emergence of a new mode of transport, which poses numerous interconnected challenges. Despite these challenges, electromobility is here to stay and electric buses are without a doubt a driver for bringing more sustainable transport to urban areas around the world. In short, they are certain to reshape both how we perceive and experience public transport across the urbanising world of the 21st century.


Riding into the future

Lars Backström is a man with a mission. He has no shortage of words when telling Pulse about the ambitious goals he has set for Västtrafik, the public transport authority he heads in southwestern Sweden’s Västra Götaland county.

Pulse #1 7 min

Take off – a bigger role for cable cars in urban transport?

When you think about the different ways that people get around cities, cable cars are not the first thing that come to mind. We associate them with skiing holidays and mountain resorts, but a growing number of cities around the world are also harnessing their potential.

Pulse #1 7 min