How much grid capacity can smart charging really save you?
The honest answer: often enough to avoid an upgrade entirely — because your simultaneous peak is far lower than the sum of your chargers.
Last updated 15 August 2026
It’s the question that decides a lot of budgets: if you add smart charging, how much grid capacity do you actually save? The honest answer is “it depends” — but the logic is simple enough to reason about before you get a formal design.
The gap between rated and real
Add up the maximum power of every charger and you get a big number — the figure a naive design would send to your DNO. But your vehicles almost never all draw that maximum at the same instant. The simultaneous peak — what you actually need — is much lower, and smart charging is what safely lets you design to it rather than to the worst case.
Diversity does the heavy lifting
Planners apply a diversity (or simultaneity) factor to capture this: if you assume only, say, 60–70% of chargers are ever busy at full power at once, your required capacity drops by a third or more. Smart charging enforces that assumption in software, so it’s not a hopeful estimate — the system actively prevents everything peaking together. Longer overnight dwell times allow a lower factor still, because there’s more time to spread the load.
What that means in practice
For many depots, the saving is the difference between needing a grid reinforcement and comfortably fitting inside the existing connection. That’s not a marginal cost — reinforcement can run into tens or hundreds of thousands of pounds and many months of delay. Spending on smart charging to avoid it is one of the highest-return decisions in the project.
The only way to get your specific number is to model your charger mix and dwell times — the Grid Capacity Estimator gives a first read you can take into the DNO conversation. But the direction is reliable: managed charging almost always needs far less capacity than the raw charger total suggests.