Solar Panel Output Calculator
Estimate daily and monthly solar energy from array size and peak sun hours
Estimated daily energy
How we calculated it
About the Solar Panel Output Calculator
Solar Panel Output Calculator estimates electrical energy produced by a photovoltaic array from panel wattage, quantity, sunlight hours and system losses. It is useful for early-stage sizing and comparing expected daily or annual production.
A solar panel’s nameplate wattage is measured under standard test conditions. Real output changes with temperature, orientation, shading, inverter efficiency, dirt and local weather.
How to Use the Solar Panel Output Calculator
- Enter panel wattage.
- Enter the number of panels.
- Enter average peak sun hours for the location and season.
- Enter system efficiency or loss factor if supported and calculate expected daily or annual energy.
How the Calculation Works
Array DC power = panel watts × panel quantity.
Estimated daily energy = array kW × peak sun hours × system efficiency. Annual energy can be approximated by multiplying daily output by 365 when the sunlight input already represents a suitable annual average.
Worked example
Solar Panel Output Calculator Worked Example
10 panels at 400 W, 5 peak sun hours, 80% system efficiency
Array size = 4 kW. Daily energy ≈4×5×0.80 = 16 kWh.
Result guide
Understanding Your Solar Panel Output Calculator Result
Sixteen kWh/day is an expected-energy estimate under the selected sun and loss assumptions, not a guaranteed output for every day.
Before you rely on the answer
Assumptions and Limitations
- Peak sun hours are appropriate for the location and period.
- Panel count and wattage reflect the installed array.
- System loss factor includes relevant real-world losses without double-counting.
Practical tip
Using This Result in Practice
For seasonal planning, calculate winter and summer scenarios separately. An annual average can hide months when production is too low to meet an off-grid load.
Related calculations
Useful Calculations to Continue With
If you need storage sized around solar production and loads, use the Solar Battery Bank Calculator.
If you want to compare system cost with electricity savings over time, use the Solar Payback Calculator.
Common questions
Solar Panel Output Calculator FAQ
What are peak sun hours?
An equivalent number of hours per day at 1,000 W/m² solar irradiance, used to simplify daily energy estimates.
Why is actual output lower than panel nameplate power?
Temperature, orientation, inverter losses, wiring, dirt and weather reduce real production.
Can I multiply panel watts by daylight hours?
Not directly. Peak sun hours better represent the varying intensity of sunlight through the day.