Dynamic Load Balancing - EV Charging

Nov 4, 2022

What is Dynamic Load Balancing and how does it work?

Last updated: Nov 16, 20227 minutes read

When shopping for an EV charging station, you may have had this phrase thrown at you. Dynamic Load Balancing. What does it mean?

It's not as complicated as it first sounds. By the end of this article you’ll understand what it’s for and where it is best used.

What is Load Balancing?

Before we start with the ‘dynamic’ part, let’s start with Load Balancing.

Take a moment to look around you. You may be at home. The lights are switched on, the washing machine is spinning. Music is drifting out of the speakers. Each of these things are powered by electricity coming from your mains. Of course, nobody thinks about this, because, well… it simply works!

However, every once in a while you do think about it. All of a sudden, the lights go off. The washing thuds to the bottom of the barrel. The speakers go silent.

It’s a reminder that every building can only handle so much current. Overload your circuit and the fuse box trips.

Now imagine: you try to flip the fuse back on. But moments later it trips again. Then you realise you have not only the washing machine, but the oven, dishwasher and kettle running too. You turn some appliances off and try the fuse again. This time the lights stay on.

Congratulations: you have just done some load balancing!

You figured out that there was too much on. So you paused the dishwasher, let the kettle finish boiling, then let the dishwasher run again. You ‘balanced’ the different loads that are running on your household electric circuit.

Load Balancing with Electric Vehicles

The same idea applies to electric car charging. Too many EVs charging at the same time (or even one EV and too many household appliances), and you risk tripping the fuse.

This is especially a problem if your house has old electrics, and can’t handle too much load. And the cost to upgrade your circuits often seems astronomical. Does that mean you can’t charge an electric car, or two, from home?

There is a simple way to reduce the costs. The answer, again, is load balancing!

Don’t worry, you don’t have to run through the house constantly switching on and off appliances to keep it all running.

Many of today’s EV chargers have built-in load management capabilities. It’s definitely a feature to ask about, when shopping for a charger. They come in two flavours:

Static and…you guessed it: Dynamic!

What is Static Load Balancing?

Static load balancing simply means that your charger has a pre-programmed set of rules and limits. Let’s say you have an 11kW charger. With static load balancing, you (or your electrician) may programme a limit to ‘never exceed 8kW power consumption’ for example.

In this way, you can always be sure that your charging setup will never exceed the limitations of your household circuitry, even with other appliances running.

But you may be thinking, this doesn’t sound very ‘smart’. Wouldn’t it be better if your charger knew how much electricity is being consumed by other appliances in real time, and adjusted the charging load accordingly?

That, my friends, is dynamic load balancing!

What is Dynamic Load Balancing?

With dynamic load balancing an appliance is able to intelligently adjust how much power it draws so that it always operates at a happy optimum.

If your EV charge point has this capability, it means that it never draws too much power.

Imagine you come home from work in the evening and plug in your car to charge. You go inside, switch on the lights, and start prepping dinner. The charger sees this activity and dials down the energy it asks for accordingly. Then when it's bedtime for you and your most demanding appliances, the charger steps up the energy demand again.

The best thing is that all of this happens automatically!

You may not have an issue with your household electrics. Do you still need such a home power management solution? The next sections look at what benefits a smart charger with dynamic load control offers. You will see that in some applications, it is essential!

Dynamic Load Balancing In A Multi-EV Household

Charging one car adds a lot of load to your household circuits. Charging two electric vehicles is an even bigger strain. Just like the scenario of having lots of appliances running at the same time, dynamic charging makes this manageable.

You can even prioritise vehicles, so if you have a visitor whose car needs to be charged first, dynamic energy management can take care of this too.

How Does Dynamic Load Balancing Benefit Your Solar Installation?

If you have a photovoltaic (PV) installation in your home, it gets even more interesting.

Sunshine comes and goes and the solar energy generated varies across the day. Whatever isn’t used in real time is either sold back into the grid or stored in a battery.

For many PV owners, it makes sense to charge their EVs with solar.

A charger with dynamic load balancing is able to continuously adjust the charging power to match how much solar juice is available at any given moment. In this way you can maximise the amount of solar going into your car and minimise electricity use from the grid.

If you have come across the terms ‘PV charging’ or ‘PV integration’, then such load management capabilities play a key part in this system. 

How Does Dynamic Load Balancing Benefit Your Business?

Another situation where dynamic energy management plays a vital role is for owners of a fleet of electric vehicles or business owners with parking and charging services for multiple EV drivers.

Imagine that you are a company with a fleet of EVs for your support team and executives and that offers free charging for your employees.

You could spend tens of thousands of euros beefing up your electrical infrastructure. Or you could rely on dynamic load balancing.

With cars coming and going, and many charging at the same time, dynamic load balancing ensures that the fleet is charged as efficiently and safely as possible.

Sophisticated systems also allow for user prioritisation, so that the most urgent charging tasks are completed - for example if the support team’s vehicles always need to be ready to go. This is sometimes called priority load balancing.

Charging many cars simultaneously, often implies that you have a high number of charging stations. In this scenario, keeping the electrical load under control while managing extensive charging infrastructure, means that some kind of charger management system should complement the load management system.

Load Management System vs. Charger Management System

  • Load Management System: This is just another way of talking about load balancing!
  • Charger Management System: Imagine if you were a business with tens or even hundreds of chargers in your car park. Wouldn’t it be great to have some kind of digital platform that allows you to monitor all these chargers at once. That’s a Charger Management System! It allows you to manage the users, do diagnostics, analytics, fleet management, and even load management.

Summary

Load balancing in one form or another is a handy feature in most electrical circuits. In a setup with an EV charger, it's highly recommended.

As soon as you consider adding solar power to the mix, or if you need to manage a fleet of vehicles or chargers - be it at a workplace, residential complex or customer parking lot - then an intelligent way of managing all that energy demand is essential.

And this is where dynamic load balancing comes in. It keeps your electrical circuit purring along nicely, while ensuring that the cars connected to the system charge as quickly and sensibly as possible. All while saving you from spending jaw-dropping amounts to physically upgrade your electrics.


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