Use this rooftop solar annual output calculator to turn operational assumptions into a clear planning estimate. Enter values that match your own workload or site, then review the main result, supporting metrics, and interpretation. The calculation runs locally in your browser and exposes every major variable, making it useful for scenario comparison, budgeting, and early-stage design. Results remain estimates and should be checked against measured performance and project-specific constraints.
The estimate converts rated DC capacity and average peak sun hours into annual AC energy after a single net-efficiency factor. It does not replace a site-specific production simulation.
Planning estimate only. Confirm important decisions with measured data, provider documentation, equipment specifications, and qualified professionals where appropriate.
An 8 kW array with 4.5 peak sun hours per day, 80% net efficiency, and 365 days produces 10,512 kWh/year, averaging 28.8 kWh/day.
No. They express daily solar energy as equivalent hours at peak irradiance.
It can combine inverter, temperature, wiring, soiling, shading, mismatch, and availability losses.
Use the number of days in the period being estimated.
No. The calculation represents the entered conditions; reduce efficiency or capacity for later-year scenarios.
Only indirectly through the peak-sun-hour or net-efficiency inputs.
| Item | Meaning |
|---|---|
| Variable | Meaning |
| DC capacity | Panel nameplate total |
| Peak sun hours | Equivalent full-sun energy per day |
| Net efficiency | Combined remaining share after losses |
| Operating days | Days represented by estimate |