Solar watts, kWh and inverter output: what the numbers mean
Plug-In Solar Compare

Solar watts and energy: a quick reference

When a quotation uses a number without a unit, ask for it to be clarified. A battery capacity, inverter output and annual generation estimate cannot be compared as if they describe the same thing. The arithmetic below illustrates units only; it does not specify a compliant device or predict its performance.

[ ] W / kW
Power at a moment
400 W = 0.4 kW
Notes: ______________________________

[ ] kWh
Energy over time
0.4 kW held for 3 hours = 1.2 kWh
Notes: ______________________________

[ ] Panel peak rating
Rated power under test conditions
Two 450 W panels total 900 W rated capacity
Notes: ______________________________

[ ] Inverter mains rating
Separate AC output specification
Read the exact unit and device documentation
Notes: ______________________________

A personal purchasing checklist, not confirmation of suitability, permission or safety.
Guide sources checked: 2026-09-06. Check current guidance and exact product information before purchase.


Read the full guide: https://pluginsolarcompare.co.uk/guides/solar-watts-kwh-inverter-output