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When a BESS could be right for your EV charging site

Adding a battery energy storage system (BESS) to your EV charging hubs can help overcome challenges.


In fact, it can give previously unviable locations new potential while also providing a boost to existing EV charging infrastructure.

If you are planning on installing an EV charging hub, consider the feasibility of including battery energy storage from the outset. Here are some of the factors that can make battery energy storage a worthwhile addition:

1. When faced with a challenging import capacity

The primary challenge faced by charging hubs is maximum import capacity (MIC). This is the amount of power you can take from the grid. While work is underway to upgrade the grid, the infrastructure is still old in many places.

This often means that MIC falls way below the amount required to power multiple fast chargers, never mind rapid chargers and the ultra-high-capacity charge points needed for trucks and buses. Want to install a 50kW charger but only have a 40kW MIC? Use a BESS to bridge the gap.

2. When a DNO upgrade is cost-prohibitive

Upgrading a site’s grid connection to accommodate charging hubs can be prohibitively expensive.

Upgrading transformers and cables can cost up to £100,000, while sites with higher demands can see costs in the millions. Equally, if you breach MIC and draw down more power than allowed you can face penalty fines, charged by the kilowatt.

3. When a DNO upgrade could impact on your timescales

DNO upgrades take time. There is increasing demand for upgrades to meet the requirements of EV charging, both for public access hubs and for fleet depots or workplaces. In order to deal with these requests fairly, DNOs operate a queue system.

In addition, they also require permission to carry out the necessary works. Combined with increased demand, this means that waiting six months for a DNO upgrade is fairly common – and it could take even longer.

If this does not fit with the timescale for delivering your project, a BESS can ensure you still meet your deadlines, while also providing a cost-effective alternative.

4. When including renewables

Adding solar PV arrays to charging hubs is a great way to power EVs with renewable energy. However, during periods of low demand, that green electricity is not used.

A BESS can be integrated with the grid and on-site renewable generation, helping to decarbonise EV charging by maximising use of green energy. The BESS stores the unused energy generated by the solar array, significantly boosting the return on investment from renewables.

5. When trying to make a business case

For private sector operators, charging hubs need to deliver a clear and foreseeable return on investment. For the public sector installing free charging points to incentivise adoption of EVs, budgets are limited, and all expenditure must be justified.

A smart BESS can respond to changing electricity tariffs in real time, charging the batteries on low-cost, off-peak tariffs, then discharging that energy for use when tariffs are higher. Battery energy storage can also significantly improve the ROI on renewables – and indeed a BESS integrated with the grid and on-site renewables can optimise the use of both.

6. Doing the sums

If you consult with a BESS provider, like Connected Energy, in the early stages of your project, they should be able to use data to accurately project the costs of various scenarios for you, with or without energy storage. This enables you to take a strong business case either way to your board of directors.

At Connected Energy, we undertake a feasibility study at the start of every project to calculate financial and carbon benefits. This assessment is then presented back to a customer in a bespoke document with the results and our recommendations.

We can even include different scenarios within the feasibility study, for example, to show you what would happen if you ramped up or down the amount of solar PV, or how a different mix of chargers would work.

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Get in touch with our team to discuss whether battery energy storage can work for your business.