Think of it like water in a hose: kW is the pressure and flow rate, kWh is how many gallons actually came out. A 7.2 kW charger running for two hours delivers 14.4 kWh of energy to your car.
In practice: your electricity bill is measured in kWh (how much energy you consumed that month). A solar installer talks in kW when describing system size and kWh when estimating annual output. Home batteries are rated in kWh (how much they store) and kW (how fast they can discharge). Getting these straight makes it much easier to compare quotes — a “10 kW solar system” and a “10 kWh battery” are very different things.
When you’re getting quotes
Watch for this in solar proposals: installers typically show system size in kW and estimated annual production in kWh. Compare the annual production figure against your actual annual consumption (found on your Duke Energy bill or account portal). For batteries, the kWh number tells you how long it can power your home; the kW number tells you how many appliances it can run at once. Both matter.