Solar Panel Output Calculator
Estimate daily and monthly solar energy production.
How Solar Panel Output Is Estimated
Solar energy production depends on the installed system size, the site’s average peak sun hours and the overall efficiency of the system. This calculator turns those three inputs into an estimated daily and monthly energy output.
Formula
Daily Output (kWh) = System Size (kW) × Peak Sun Hours × Efficiency
Worked Example
A 6 kW solar system receiving 5 peak sun hours per day at 80% efficiency produces about 6 × 5 × 0.80 = 24 kWh per day, or approximately 720 kWh in 30 days.
Factors That Affect Solar Production
Cloud cover, seasonal daylight, panel orientation, tilt angle, shading, temperature, inverter efficiency, wiring losses, dirt and panel degradation all affect actual output. Peak sun hours are not the same as total daylight hours, so use a realistic local solar resource estimate.
Frequently Asked Questions
What are peak sun hours?
Peak sun hours represent the equivalent number of hours per day when solar irradiance averages 1,000 watts per square meter.
Why is system efficiency below 100%?
Real systems lose energy through inverters, wiring, heat, mismatch, shading and other operating conditions.
Can I use this to estimate annual production?
Yes, but a single daily value is only approximate. For better annual estimates, use monthly peak sun hour values to capture seasonal differences.
Methodology and Practical Limits
Solar energy is approximately panel rated power × effective peak-sun-hours × system efficiency. Weather, orientation, shading, temperature, inverter losses and seasonal variation mean nameplate wattage alone cannot predict daily production.