kW vs kWh in Energy Storage: Why Both Matter
Two numbers appear in almost every energy storage project: kW and kWh. They describe different parts of system performance, and confusing them leads to poor sizing decisions.
kW describes power
Power is the rate at which the system can deliver or absorb energy. It determines whether the storage system can support the required load at a given moment.
kWh describes energy
Energy capacity describes how much energy can be stored and used over time. It affects how long the system can sustain a given load before recharging is required.
They must be sized together
A project may need high power for a short peak or lower power for a long duration. The load profile, operating strategy and usable depth of discharge determine the practical combination.