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Finding the Right Balance, With Load Balancing

Can you meet the growing demand for workplace EV charging without an expensive upgrade to your local electricity grid? In this article, we explain how load balancing can help.

Electric Vehicle Using Load Balanced Charge Points

As demand for workplace charging grows, many organisations are finding that their premises are simply not designed to cope with the number of EV chargers they need. This is because your local grid infrastructure was not designed or built with EV charging en masse in mind. 

“We are seeing increasing enquiries for help to overcome energy capacity restrictions,” says Naomi Nye, head of national sales at Mer. “Typically, these sites are older, meaning they don’t have the infrastructure required to support lots of EVs – because EVs didn’t exist when these premises were designed and built. No one envisioned the energy requirements of electric vehicles.  

“When EVs charge they pull a full charge for as long as they possibly can. If you have quite a few vehicles charging at once, this can cause problems. Even if you have five, ten or twenty charge points you are consuming quite a lot of energy.” 

The traditional way to get more power was to pay your district network operator (DNO) to upgrade your local infrastructure. 

“You can get a DNO upgrade, but it is hugely expensive – you are not likely to see a return on investment for decades, never mind years,” adds Naomi. “It can also take a long time – several months is not uncommon.” 

Load balancing enables you to put more charge points on site at a far lower cost than a DNO upgrade, so it gives you the flexibility for expansion

Naomi Nye, Head of National Sales, Fleet & Workplace - Mer UK

A Smarter Solution

Load balancing can hold the key to unlocking more workplace EV charging capacity on site without the need for an expensive upgrade to your local electricity grid.  

“Load balancing enables you to put more charge points on site at a far lower cost than a DNO upgrade, so it gives you the flexibility for expansion,” says Naomi. “At Mer we can offer load balancing as an upgrade as and when you need it, you don’t have to install it when you install your first charge points. Your site doesn’t need to be all singing and all dancing from day one.” 

How it Works

Fundamentally, load balancing is about fairly distributing the available power to multiple vehicles. And best of all, smart chargers can be programmed take care of this automatically. 

For example, on a 22kW rapid charger with two sockets, if one vehicle plugs in it will be able to draw the full 22kW. If a second vehicle also plugs in, each vehicle will get 11kW. All the hardware required is already embedded in Mer’s smart chargers, meaning this is a very cost-effective option. “This is load balancing at its most basic, but it can also handle more complex requirements,” says Naomi. 

Mer Workplace Chargers in Car Park

Building a Network

If you have a bank of smart charging points, Mer can take this to another level, by connecting them together to create a smart charging network. “The network understands how much power is available in total,” says Naomi. “The chargers communicate with each other and automatically ramp up and down how much charging they are giving to vehicles, in order to stay under that limit.  

“If your site reaches the point that if all charging sockets are in use there is not enough power to feed all the vehicles at once, then they all start alternating. For example, unit one stops while units two and three charge their vehicles, then two stops while one and three charge, and so on. 

“Certain EVs charge at different rates to others. For example, some Renault models will only take a charge above a certain amperage. The charge point will identify that it has a Renault plugged in, communicate this to the rest of the network and ensure that it gets the right amperage to ensure the vehicle charges.” 

Dynamic Loads

A lot of workplace electric vehicle charge points are located on buildings or sites that have other power requirements – for example, an office will use energy for lighting and powering computers; maybe it has escalators or elevators as well. “This is what is known as an active or dynamic load because it constantly changes. Telling a smart charging network that the limit is 100A would be inaccurate because one second there might be 105A available and the next it might only be 95A. 

“In these circumstances, we would recommend nominating one of the charging points as the master unit and connecting it to your building management system (BMS) or energy management system (EMS),” says Naomi. “In this way, the charge point network gets real time updates about the power parameters in which it must work. The network can then ramp up or down based on the live data from the BMS.” 

It is all about using technology to create a more holistic approach to energy generation, usage and management.

Renewable Energy

If you have energy storage and renewable energy generation on site, such as a solar PV array, then you can also use dynamic load balancing to integrate them with your charge point network. 

“By linking the network to an EMS or BMS you can instruct the charge points to draw energy from those renewable sources,” says Naomi. “It is all about using technology to create a more holistic approach to energy generation, usage and management. 


While you might not need load balancing on site yet, it will only be a matter of time. The transition to EVs is underway and the number of drivers wanting to charge their vehicles at the workplace will incrementally increase year on year. By choosing Mer smart chargers, you have the flexibility to turn on load balancing in the future, when you’re ready for it.  

“Customers appreciate having this flexibility,” says Naomi. “Fundamentally it is about future-proofing your sites so you are ready for the changes that will inevitably come down the line.  

“It can sound like a daunting prospect, but it doesn’t have to be. We’re experts at load balancing, which is one of the reasons more organisations are choosing Mer for their workplace charging.” 

At Mer we are experts in workplace charging, and we’re happy to share our expertise to help you on the road to net zero. Our belief is that you shouldn’t have to be an energy expert – that’s our job.  

Click here for further information on Mer charging infrastructure options or get in touch at [email protected] for a friendly chat with one of our team. 

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