Power and Energy Are Not the Same Thing (kW vs kWh)
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One Minute Charge #03
Why confusing these two units can lead to expensive electrification decisions
Two numbers show up constantly in discussions about EVs and charging: kilowatts (kW) and kilowatt hours (kWh). They sound similar, and people often mix them up. But they measure very different things.
Power (kW) is how fast electricity can be delivered. Energy (kWh) is how much electricity is actually delivered.
A simple way to think about it is water flowing through a pipe. Power is how fast or hard you can push the water through the pipe. Energy is the total number of gallons that comes out.
This distinction matters because power is what makes charging infrastructure expensive. Higher power charging often requires larger transformers, upgraded electrical service, and sometimes utility grid improvements. Those upgrades add cost and can significantly slow deployment.
Energy is what actually creates value. Every kWh delivered to a vehicle replaces gasoline or diesel that would otherwise be burned. It’s what moves the vehicle, generates fuel savings, and reduces emissions.
That’s why many electrification projects try to avoid expensive power upgrades while maximizing the amount of energy delivered over time.
Because in the end, power (kW) determines how much infrastructure you have to build. But energy (kWh) is what actually does the work.