How is a load-managed site planned?
The company wants to double the car park to forty charge points. The facility manager starts with the question the planner always asks first:
how much energy do the cars actually need?
The questionHow do you size a site with load management?
forty charge points of 11 kW
forty cars at about 12 kWh each
480 kWh over nine hours
room for peaks and pool cars
A composed example. 12 kWh covers a commute of about 70 km at 17 kWh per 100 km.
How many cars, how far they drive, how long they stand. That gives the energy per day.
Select each step to see the question it answers.
The usual mistake
Sizing the connection for every charge point at full power, 440 kW in this example, makes a site expensive for a peak that the cars' energy need does not require. Sizing it too tight makes cars miss their departure. lets the planner size for the energy, with a reserve, and grow the number of charge points without growing the connection at the same rate.
The fallback deserves its own step: under 1.6, a charger that goes offline without any stored charges as if no limit applied. A limit stored in every charger keeps the site within its connection when the controller fails.
Check your understanding
3 questions. Answer all of them to complete this stop. Each answer explains itself.
What is the first question when planning a load-managed site?
Energy need comes first; power and connection follow from it.
Forty cars need 480 kWh over nine hours. What is the average power?
480 kWh ÷ 9 h ≈ 53 kW. The reserve above that covers peaks.
Why plan a fallback limit in every charger?
A charger offline without a stored limit charges as if no limit applied, and could overload the connection.
- OCPP Open Charge Point Protocol: the open protocol between a charger and its operator's backend. EV charging fundamentals, stop 03 Glossary
- Load management Shares a site's grid connection between the cars charging at the same time. EV charging fundamentals, stop 04 Glossary
- Charging profile An OCPP message that sets a limit in amperes or watts for a station, for new sessions or for one session, valid for a time or as a schedule. Stop 03 Glossary
- Open Charge Alliance: OCPP 1.6 edition 2 (2017), section 3.13.4 Smart Charging Use Cases (load balancing, local smart charging) and section 3.13.6 on smart charging when a charge point goes offline; free download. https://openchargealliance.org/download-ocpp/. Checked 13 Oct 2026.