Eco-driving for EV bus fleets: a must have for operations performance – case studies part I

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In this article we will discuss the following topics for the management of electric vehicles:

  • TCO of an electric vehicle and advantages over long term.
  • Selection of OEMs and barriers in obtaining telemetry.
  • Key indicators in electric buses-efficiency and safety management.
  • Gains in energy, operations and autonomy based on tests with different brands.
  • Energy and range projections in a real fleet.

In recent years, the adoption of electric buses in Europe has been on the rise due to growing concerns about air pollution, climate change and the desire to reduce greenhouse gas emissions in the transport sector.

Many European cities are implementing measures to encourage the use of electric buses, such as introducing low emission zones or allocating funds for the acquisition of electric buses.
The acquisition cost of electric buses is high and has required support from governments in the form of significant subsidies. It is important to evaluate the TCO (Total Cost of Ownership) of an electric bus. The TCO is an analysis that considers, in addition to the total cost of acquisition, the cost of operating the vehicle during its useful life. And it is in this way that the electric bus stands out, due to its lower maintenance costs, significantly lower energy cost and a longer useful life, thereby reducing the total cost of ownership.

There are a number of initiatives at the European level aiming at encouraging the adoption of electric buses as part of a transition towards more sustainable forms of transport. For example, the European Commission is implementing an action plan for electric mobility with the goal to increase the number of electric vehicles in Europe. There are also financing programs available that support the acquisition of electric buses and the construction of charging infrastructure.

Overall, the adoption of electric buses in Europe is on the rise, and this trend is expected to continue as governments and businesses commit to more ambitious emission reduction targets and transition to more sustainable forms of transport. The electric bus market in Europe has grown by 26% last year, to 4,152 registered units (there were 3,282 in 2021, with a growth of 48% compared to 2020). 30% of the European city bus market now runs on zero emissions (data comes from consultancy Chatrou CME Solutions).

Transport companies are currently focused on taking advantage of the public aid available for the electrification of their fleets. But, for bus operators, the choice of a suitable OEM is a key decision. They should trust OEMs, which provide vehicle data to third parties in order to be able to integrate new vehicles into existing systems in the organization. Operators should avoid working with manufacturers that refuse to share their vehicles’ telemetry information.

Unlike the consensus achieved for the FMS standard in combustion vehicles, in the case of electric vehicles there is no common agreement for all manufacturers yet. Although some initiatives have been put in place for the standardization of the information that would be published openly for third-party telemetry systems, such as that of the ITxPT working group, the truth is that each manufacturer still establishes its own and sometimes confidential definitions, not shared with third parties, or offered exclusively through its captive OEM platform. This can be a big burden for bus operators, as it is often the case that fleets are heterogeneous, combining different brands and models, so a cross-cutting solution is necessary. For all that, the engineering teams have an important research and development work to do, to ensure that third-party systems can integrate different vehicles (ICE, hybrids and especially electric) and from different manufacturers.

Integration with third-party systems is essential and highly important in the management and operations of passenger transport companies, since it allows greater efficiency in the management of journeys, schedules, ticket sales, fleet efficiency and safety, and other tasks related to the operations of buses, improving the quality of the service, which translates into greater customer satisfaction and business growth.

A key factor that is motivating the greater presence on the roads of electric vehicles is their efficiency. Traditional combustion vehicles have an efficiency of around 25%, compared to 70% or more that current electric vehicles can achieve. That efficiency can still be improved, through the driver, by reducing the energy per kilometer consumed by the vehicle. In addition, over time, doubts about the autonomy and price of electric vehicles are dissipating.

To achieve this, it is very important to apply efficient and safe driving techniques adapted to each manufacturer, driving context and type of vehicle. It is necessary to know the specifications and characteristics of each vehicle provided by the manufacturer and adapt good practices to each specific model. Some of the main guidelines are: control the accelerator pedal so that the delivery of energy is necessary and appropriate to the circumstances, try to coast and finally, when slowing down and stopping, use the brake early and progressive to reach the maximum possible regenerative braking capacity.

An electric bus

In addition, these indications must be adapted to each driving context, since driving on a slope is not the same as driving on a flat line. It also influences if buses are operating in an area of high traffic density or interurban areas with higher average speeds, driving with many passengers or empty, on a rainy or dry day. Properly treating and interpreting driving parameters to adapt them to the context is a complex task that must be addressed by expert data engineers and specialized systems.

Obtaining and analyzing contextualized vehicle information in real time has multiple benefits: it will allow more information to be available for more efficient planning of journeys and services. It will allow knowing the estimated range of kilometers remaining adapted to the context, knowing exactly the buses’ autonomy depending on the journey. It will also help to improve battery conservation, to predict the need for intermediate fast charges, to know the optimal line for each type of vehicle or even to allow intelligent assignments. For example, to assign more efficient drivers to vehicles with less range of autonomy. It can also serve as support for the information and decision systems of the recharging networks and obviously for real time and offline recommendations to the drivers.

According to a recent study by Bledsystem, the potential for energy savings by following efficient driving is up to 35%, being able to improve autonomy by 11% on average. The potential to improve indicators of efficient and safe driving is up to 60%, which surpasses the potential for any combustion vehicle under the same conditions.

The following table shows an (conservative) estimate of energy savings and ranges based on the characteristics of a 100% electric fleet of 500 buses.

It is estimated that for a fleet of 500 electric buses, in three years energy savings of 11.880.000 kWh and an increase in autonomy of almost 8 million kilometers could be achieved.

Improving range of autonomy at such high rates, is also a great opportunity to obtain important savings, not only at fuel/power level, but in other aspects too.

Let us consider the conservative example of 10% savings on energy. This will allow a typical EV bus to run for more than the planned 4000km per month, around 4400 km. Scaling this to the entire fleet, it means that the planned objective of 2.000.000 km per month, can be achieved with less buses.

How many buses can we save? The maximum potential savings will be of 45 buses of a fleet of 500 units. However we know that the exact number will be lower, depending on scheduling rules and peak time frequency.

Nevertheless, even if we are very conservative again, ecodriving savings combined with an excellent scheduling tool can mean both a direct economic important savings of energy and a reduction of number of vehicles, and of initial and recurrent investment in assets.

In short, the potential of efficient and safe driving in electric vehicles is great and the potential benefits are huge: increase in the range of electric vehicles by 10-20%, increase in the useful life and health of batteries, increase in safety and maintenance reduction, in addition to significant energy savings. However, to succeed in achieving this potential you need to consider the key aspects suggested in this article.

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