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Navigating to Net Zero: Energy Storage for Ports

As with other industry sectors, UK ports and harbours are working hard to decarbonise ahead of the 2050 Net Zero deadline. Some operators such as ABP and Peel Ports are more ambitious, aiming for Net Zero a full decade earlier.


A key element in their decarbonisation strategies is the electrification of vehicles and material handling equipment (MHE), as well as providing ship-to-shore power. In some cases, it will also mean providing charge points for all-electric leisure boats.

However, for many UK ports and harbours, their local grid infrastructure is insufficient to support these electrification targets. In this article we look at what ports are trying to achieve, some of the challenges they face, and how battery energy storage systems can help solve these issues.

Why are ports electrifying?

The International Maritime Organisation (IMO) is asking for a 40% reduction in carbon intensity of international shipping by 2030 compared with 2008 – and to reach net-zero greenhouse gas emissions by or around 2050.

The nature of port operations means they are currently quite carbon intensive. For example, a recent study by Transport & Environment found that Rotterdam was responsible for almost 14 million tonnes of CO2 per year, making it the largest industrial polluter in Europe.

Electrification offers the best route to Net Zero, replacing diesel fuel use with electricity wherever possible.

What are the barriers to port electrification?

Grid capacity constraints are a serious issue. British Ports Association research found that 70% of UK ports are already at or near their ceiling in terms of available power. This means that, in order to support electrification, they must either invest in costly grid upgrades, generate their own energy from on-site renewables, or install battery energy storage systems (BESS) to overcome grid capacity challenges.

How can energy storage help ports decarbonise?

Battery energy storage systems are often modular, meaning they can scale up to address several of the challenges facing ports:

Support EV charging

All industrial and commercial facilities have an agreed maximum import capacity (MIC) with their energy provider. Sometimes also known as a kVA allowance, this is the limit on how much power the site can draw down from the grid. Breaching MIC results in significant surcharges.

This poses problems for ports planning to deploy EV charging stations at scale, in order to support electric vehicles, electric MHE, and electric leisure boats – if too many EVs are plugged in at once, the site could go over its kVA allowance.

BESS is a proven way to provide the power needed while avoiding MIC surcharges. The BESS acts as a reservoir, drawing down energy during quiet periods and providing it during times of peak demand.

Optimise renewable energy generation

Many ports are installing solar PV arrays to generate as much of their own clean energy as possible. However, ports are 24-hour operations, and clearly solar does not provide power at night.

A BESS solves this issue as it can store surplus solar energy generated during the day and provide it during hours of darkness. In this way, ports can “oversize” their solar capacity to power more night-time operations with renewable electricity.

Avoid infrastructure upgrades

Even without factoring in ship-to-shore provision, some ports are already unable to access more power from the grid to support other electrification goals. Where a new substation is simply not a viable option, BESS can provide a more affordable alternative.

Enable provision of ship-to-shore power

A survey by the British Port Association published in 2020 found that the two biggest barriers to deploying ship-to-shore facilities were lack of capacity in the local transmission network and the high capital outlay required to remedy it:

“The costs of potentially having to upgrade local energy networks were cited by most people we spoke to and respondents to our survey identified it as the biggest barrier. The second highest barrier identified was lack of capacity in the local energy network, which is related to the capital costs barrier.

“Large vessels will require in the order of 5MW per connection which could be a quarter or half the typical demand for a small to medium port. This connection will inevitably put stress on local energy networks, which requires either significant capital expenditure on reinforcement to remedy, or energy storage.”

In the same way that BESS can support EV charging, it can also be deployed at scale to bridge the “power gap” for ship-to-shore.

Can ports use second life energy storage systems?

Battery energy storage systems do not have to use new batteries. Companies like Connected Energy take batteries from end-of-life EVs and give them a second life in stationary energy storage.

Based on real-world data from existing operational systems, one of our 300kW E-STOR systems provides a positive benefit of 150 tonnes of CO2e compared to a BESS made using brand-new batteries.

In addition, just one Connected Energy 300kW/360kWh BESS can save the use of 100 MWh of grid electricity which at present is the equivalent of 18 tonnes of carbon emissions each year.

By specifying second life BESS, ports can increase the environmental benefits and contribute to the circular economy. Ultimately, we could see batteries from end-of-life port equipment repurposed in second life BESS to power the ports of the future.

Where can I find further information on BESS for ports?

Join us for our forthcoming webinar – on Wednesday 22 November – where we’ll be discussing the role of battery energy storage for ports and harbours. You’ll learn more about the various applications of battery energy storage whether that’s capturing renewables, managing peak loads, or supporting the electrification of vehicles and machinery. And discover how to implement this new technology…

Book a free space here.

Download our new brochure

Downlaod our guide for the ports and harbours industry on how battery energy storage systems is supporting energy management for ports and harbours.