Solar Output / Production Estimator
How many kWh will a solar system actually generate where you live? Enter the system size and your region's sun hours, and see daily, monthly, and yearly production — plus what that power is worth at your rate.
Real-world losses. 0.78 typical; lower if shaded or hot.
Annual production
0 kWh
from a 6 kW system
Estimates only. Orientation, tilt, shading, and season change real output — winter days can produce a third of summer days.
How this solar output estimator works
The industry-standard estimate: annual kWh = system kW × peak sun hours × 365 × performance ratio. Peak sun hours capture your location's solar resource; the performance ratio (default 0.78) captures everything a real installation loses to inverters, heat, wiring, and dust. Unlike our other solar tools, the PR is editable here — drop it to ~0.70 for partly shaded roofs, raise it toward 0.85 for cool climates with premium equipment.
Solar output FAQ
How much power does a 5kW solar system produce?
With 4 peak sun hours: 5 × 4 × 0.78 ≈ 15.6 kWh/day, roughly 5,700 kWh/year. With 5.5 sun hours the same system yields about 7,800 kWh/year.
What is a solar performance ratio?
The fraction of theoretical output a real system delivers after inverter losses, heat, wiring, soiling, and mismatch. 0.75–0.85 is typical; 0.78 is a solid planning default.
Why does my system produce less than the calculator says?
Shading during peak hours, poor orientation or tilt, high roof temperatures, dirt buildup, or inverter clipping. Seasonal swing also means winter days can produce a third of summer days.
How do peak sun hours differ from daylight hours?
Peak sun hours compress the day's sunlight into equivalent hours of full-strength (1,000 W/m²) sun. A 14-hour summer day might deliver only 6 peak sun hours because morning and evening light is weak.