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How can energy storage support the transition to electric commercial vehicles?

When powered by diesel, buses and trucks are big emitters of air pollutants and greenhouse gases. As battery technology has continued to improve, these larger vehicles have rightly become key targets for electrification.


All-electric commercial vehicles operating in urban environments can help improve air quality as well as supporting our wider sustainability goals.

However, bigger vehicles need bigger batteries, and bigger batteries require higher-powered chargers. This is all well understood, but there is a missing piece to that equation – high powered charge points need a higher grid connection. What happens to our sustainability strategies if the costs of upgrading the grid are too prohibitive, or will take too long?

Recent studies of power requirements for regional and long-haul truck operations in the United States and Europe find that charging power higher than 350 kW, and as high as 1 MW, may be required to fully recharge electric trucks during a 30- to 45-minute break.

Depot charging

For truck and bus operators, most recharging of their EVs will take place off shift, meaning when the vehicles are parked up at a depot. However, in both sectors, most depots are older buildings. They didn’t previously require a large amount of energy to run them, and this is reflected in the quality of their grid connections.

It is important to understand that the grid is not prepared to provide the levels of power that these charge points require. Currently, the most popular charge point sizes for buses and trucks are 150kW and 350kW – but 1MW chargers are now also commercially available. To put that into perspective, a single 150kW charger is the equivalent of 21 standard 7kW car chargers on site – and using them all at once. A 1MW charger would equate to 143 7kW chargers.

Upgrading the local energy infrastructure to accommodate high-powered chargers is therefore expensive – it can run into millions of pounds. It can also take years to achieve as the distribution network operators (DNOs) responsible for carrying out this work have a backlog due to high demand.

Opportune charging

Truck operators might also need to charge during a shift, and this will become more prevalent as operators introduce HGVs on longer haulage inter-city runs rather than just intra-city urban duties.

Here, the same challenges with grid constraints apply – most truck stops and motorway service stations do not have the capacity headroom to introduce high capacity charge points. The infrastructure must first be upgraded unless an alternative can be found.

The costs will be eye-watering – according to research by PwC, a European pilot network of just 120 1MW charging stations would require total investment of up to €1bn, working out an average cost of €8.33m each. Its forecasts of 2,400 charging hubs across Europe to support road freight would require €36bn, or €15m per site.

Energy storage

With such huge sums being discussed, it makes sense to look at other options, and this is where battery energy storage systems (BESS) can come into their own. As the name suggests, a BESS is a bank of batteries that can act as an energy reservoir, making them ideal for these EV charging scenarios.

In this use case, the BESS draws down energy at a rate that is well within the grid’s capabilities. It stores this energy and can then provide it as required, at much faster rates, such as when a truck plugs into a 150kW charger. Once that truck moves on, and the charger is dormant again, the BESS reverts to replenishing its batteries from the grid, ready for the next vehicle.

In fact, BESS is already a proven solution in electric car and van charging, deployed across Europe at depots and charging hubs to increase on-site power availability. BESS can often be a quicker and much more cost-effective alternative to grid upgrades. The only difference for high-power chargers is that they require bigger energy storage solutions. However, systems like E-STOR by Connected Energy are modular, so they are ideal for these applications.

BESS can help avoid expensive DNO upgrades now, while the modularity of systems like E-STOR enables you to futureproof your sites for when 1MW chargers become more mainstream.

Other benefits

In addition to solving capacity challenges, BESS can bring other benefits to truck and bus operators.

These energy storage systems work particularly well with solar installations, capturing that renewable energy for when it is needed. So, for depots with rooftop PV arrays or charging hubs with solar canopies, a BESS can both improve the business case for solar and help to further drive down emissions. By storing surplus solar power, the BESS reduces reliance on grid energy and accompanying cost and carbon footprint.

Even if you don’t have solar on site, a BESS can still provide financial and environmental benefits. They can be instructed to only take energy from the grid when it is at its cheapest, or when renewable energy is in abundance.

And if you choose E-STOR from Connected Energy, you are getting the most sustainable BESS on the market, as it uses second-life batteries taken from end-of-life electric vehicles. In this way, the batteries from yesterday’s EVs help to support the batteries of EVs today and tomorrow.

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Get in touch with our team to discuss whether battery energy storage can work for your business, and how we can offer a free feasibility study.