Riding the wave of electrification: Why public transport and logistic fleets need ‘smart homes’

Jean-Christoph Heyne
February 7, 2021

In countries all over the world, electrification targets in public transport – and mobility in general – are very ambitious, and as I intend to argue, rightly so. Globally, mobility accounts for one third of the energy demand and a quarter of carbon emissions. In the mobility sector, public transport and urban logistics with their buses, trucks, and commercial vehicles represent a major lever for winding down emissions if renewable energy is used to fuel the electrified vehicles.

We know that full decarbonization in all areas is vital for combatting the climate crisis and achieving the goals of the Paris Agreement. As outlined in the IPCC Special Report on Global Warming of 1.5°C,[i] we not only need to flatten the carbon curve; we need to turn it around fast in the next couple of years. There is no Planet B, and we really cannot afford to mess this up.

By embracing full decarbonization in the mobility sector, a decisive contribution can be made to combatting the climate crisis – while drastically improving the quality of life in our cities.

Make no mistake, this will involve disruptive change for all players in the mobility market: public transport operators (PTO), logistics providers, local governments, private investors in urban infrastructure, and original equipment manufacturers (OEM). However, this change is not as painful as it may sound. We have nothing to lose, but everything to gain by embracing this next cycle of disruptive innovation: Cleaner air, more livable cities, and a better quality of life for everyone are within our reach.

The good news is that the solutions for the electrification of public transport are already available, and the first large-scale electromobility projects have been successfully implemented.

The Chinese megacity of Shenzhen stands out as one of the early adopters, becoming the world’s first major city to run an entire bus fleet – of over 16,000 buses – completely on electricity. As a result, the city has been able to avoid 440,000 tonnes of carbon emissions per year and curb its notorious pollution, while also reducing its fuel bill by 50 percent. Further megacities in the Pearl River Delta and the rest of China are set to follow in Shenzhen’s footsteps.[ii]

Trailblazers and drivers in bus fleet electrification

Going forward, megacities and their electromobility strategies will play a major role in driving the intelligent management of public and private fleets of electric vehicles, as well as the smart electrification of urban logistics and public transport. But international initiatives such as C40 Cities have also made strong commitments by signing the Fossil Fuel Free Streets Declaration.[iii]

In this context, PTOs and logistics providers are emerging as natural trailblazers for electrification due to their limited daily range, as well as their predictable stops and standstill times. All of these factors lend themselves to recharging. Already today, more than half of newly purchased buses are electric. By 2040, two thirds of the entire global bus fleet are expected to be electric, which amounts to a tripling of electromobility in the public transport sector. Twenty-four percent of light commercial vehicles, like delivery vans, will become electric, too.

While we are obviously seeing some momentum, it is also important to ask: What has been holding PTOs and logistics providers back from fully transitioning to electromobility so far? Of course there is the hurdle of the initial CAPEX of procuring new vehicles – currently, the price of e-buses can be nearly twice that of conventional diesel buses. However, this is quickly offset by a lower total cost of ownership, reduced downtime, and lower fuel costs. Most importantly in terms of cost, an increase in the size of electric fleets requires the establishment of viable, affordable charging infrastructure.

Whether this infrastructure is funded by the public sector, as in the case of PTOs, or by the private sector, as in the case of logistics depots, any investments will have to be carefully deliberated and must pay off in the medium or long term. Subsidies or incentives should also be considered so that PTOs and logistics providers can decrease their emissions and still increase their profitability, because there is an – albeit not always quantifiable – added value in transforming cities into sustainable, livable spaces. In the case of Shenzhen, the Chinese government invested US$1 billion in order to successfully electrify the city’s bus fleet in only eight years.

The depot reimagined as microgrid merging generation, storage, consumption

While opportunity charging solutions exist en route, most of the charging of e-buses will take place overnight in depots. The depots we have today, however, are not designed to supply an electric vehicle fleet with energy. The standard grid connection of a bus depot with around 200 diesel buses will run at 100 kW. However, the grid connection of a bus depot with around 200 e-buses will require 10 MW, with peak load increasing demand by a factor of 100.

EMobility Sicharge UC Depot Small

The smart, integrated depot of the urban e-vehicle fleet of the future.

What are the solutions? One option would be a costly grid expansion, which might attract higher charges from the power supplier; another would be to install a storage unit as a buffer, which would store power during the day for load balancing at night. Either way, it is important to choose a solution that balances grid limitations with the high load needs of depot charging. In addition, it is worthwhile to reimagine the depot as a location not only for energy storage and consumption, but also for onsite power generation. Most depots feature large roof areas that are ideally suited for the installation of photovoltaics.

Madrid is one of the cities taking into account all three aspects of generation, storage, and consumption in planning the replacement of its La Elipa depot with a capacity for 330 electric buses. The futuristic building with an area of 40,000 square meters, 32,000 of which will be dedicated to bus parking, will be covered with solar panels and generate photovoltaic energy for its own consumption. Furthermore, a 40-MW substation will be installed.[iv]

Smart depots: Why software integration is key

As this example clearly shows, simply putting charging points in place will not be sufficient on its own – when electrifying a depot, the whole energy supply and demand will need to be considered, encompassing renewable generation, storage integration, and charging potential on location.

Such a holistic approach to depot charging will need to be coupled with intelligent load management in order to increase energy efficiency and ensure reliable power supply. In fact, depots can be designed as intelligent microgrids, effectively turning them into smart infrastructures. On the charging level, intelligent charging management softwarewill offer seamless, optimized operations – e.g., to ensure that the individual e-vehicles have reached the desired state of charge by the time they are ready to leave the depot. Dynamic charging helps to prioritize charging processes accordingly. On the general level, energy monitoring and management software could be implemented to control all energy assets, such as buildings, renewable power generation, storage, and charging systems.

These solutions should be cloud-based with multi-directional data exchange and predictive load management to balance the depot’s overall energy needs in the most efficient and economic way. Thus, there would not only be a flow of information from the power generation units to the grid control unit, but also a connection that provides data from and to the building management system and the charging infrastructure, for example. Furthermore, such a system could integrate data from external sources, such as weather data or energy tariffs, to forecast loads or charge when power is cheaper. Basically, software integration is the brain of the smart depot.

Future-proof solutions show the way forward

With the wave of electrification swelling on a global scale, eased along by smart solutions, depots with more than 100 buses or commercial vehicles will play an increasing role in future cities and megacities.

It is clear that for electromobility to succeed, and for full decarbonization in the mobility sector to be embraced, we need this kind of smart infrastructure. On the one hand, we will have to combine flexible charging systems with renewable energy sources and storage solutions; on the other hand, we will need to harness the opportunities of digitalization: Software to intelligently manage charging processes as well as the whole energy system of future depots will be key.

This urban charging infrastructure will need to be designed with a holistic, end-to-end perspective and adapted to the local requirements. It can be assembled and optimized in order to become the most economically viable solution for e-vehicle fleet operators.

Think of it as a smart home for the e-bus fleets that will make our cities more livable.


[i] Intergovernmental Panel on Climate Change: Special Report on Global Warming of 1.5°C, https://www.ipcc.ch/sr15/

[ii] Matthew Keegan (2018): Shenzhen’s silent revolution: world’s first fully electric bus fleet quietens Chinese megacity, https://www.theguardian.com/cities/2018/dec/12/silence-shenzhen-world-first-electric-bus-fleet (accessed July 12, 2020); Mordor Intelligence (2019): Electric bus market – growth, trends, and forecast (2020–2025), available online at: https://www.mordorintelligence.com/industry-reports/automotive-electric-bus-market (accessed July 12, 2020)

[iii] C40 Cities (2020): List of signatories having committed to the C40 Fossil Fuel Free Streets Declaration, available online at: https://www.c40.org/other/green-and-healthy-streets (accessed July 12, 2020)

[iv] EMT Madrid: Nuevo centro de operaciones de La Elipa, http://www.nuevocentroelipaemt.com/ (accessed July 12, 2020)

2024 Latest Issue

Read & Download

2024 Spring EV News Magazine

Engage with the Pioneers & Innovators who are making the shift to electrified transportation a reality.

Jean-Christoph Heyne
Global Head of Future Grids, Siemens AG

Check out my other articles

The use of Simulation in BMS and ADAS

The use of Simulation in BMS and ADAS

Dr Christophe Bianchi Closing the Gap Between Design and Reality The world’s automakers are racing to launch new EV models, and many of the engineering challenges around EVs centre on the electric...