PV Power Output Calculator

Model watts, daily kilowatt-hours, and system losses accurately. Explore weather, tilt, and temperature effects instantly. Make smarter solar decisions using transparent calculations and charts.

Enter Solar System Inputs

Site Name

Panel Rating (W)

Panel Count

Plane-of-Array Irradiance (W/m²)

Cell Temperature (°C)

Temperature Coefficient (%/°C)

Peak Sun Hours

Tilt Factor (%)

Azimuth Factor (%)

Shading Loss (%)

Soiling Loss (%)

Mismatch Loss (%)

Wiring Loss (%)

Inverter Efficiency (%)

Availability (%)

System Age Loss (%)

Performance Adjustment (%)

Electricity Rate ($/kWh)

Module Area per Panel (m²)

Module Efficiency (%)

The form uses a 3-column layout on large screens, 2 columns on medium screens, and 1 column on mobile.

Example Data Table

Scenario	Array Size	Irradiance	Cell Temp	Sun Hours	Estimated AC Output	Daily Energy
Residential Roof	5.50 kW	850 W/m²	35°C	5.5	4.13 kW	22.72 kWh
Commercial Roof	25.00 kW	900 W/m²	38°C	5.8	18.76 kW	108.81 kWh
Utility Block	100.00 kW	950 W/m²	40°C	6.0	76.20 kW	457.20 kWh

Formula Used

STC Array Power (kW) = (Panel Rating × Panel Count) ÷ 1000

Irradiance Factor = Irradiance ÷ 1000

Temperature Factor = 1 − [Temperature Coefficient × (Cell Temperature − 25°C)]

Combined Performance Factor = Irradiance Factor × Temperature Factor × Tilt Factor × Azimuth Factor × Shading Factor × Soiling Factor × Mismatch Factor × Wiring Factor × Inverter Factor × Availability Factor × Age Factor × Performance Adjustment

Estimated AC Output (kW) = STC Array Power × Combined Performance Factor

Daily Energy (kWh) = Estimated AC Output × Peak Sun Hours

Monthly Energy (kWh) = Daily Energy × 30

Annual Energy (kWh) = Daily Energy × 365

These equations provide a practical engineering estimate, not a full year-by-year simulation. For bankable studies, use detailed irradiance files, thermal models, and hourly system design software.

How to Use This Calculator

Enter the panel wattage and total number of modules.
Add site irradiance and expected cell temperature.
Set peak sun hours for your location or design month.
Adjust tilt and azimuth factors for your mounting orientation.
Enter realistic losses for shading, soiling, mismatch, and wiring.
Provide inverter efficiency, availability, and aging loss assumptions.
Click Calculate PV Output to display the result above the form.
Review the chart, summary table, and export the data as CSV or PDF.

FAQs

1. What does this calculator estimate?

It estimates PV array AC power, daily energy, monthly energy, annual energy, and value after irradiance, temperature, and system-loss adjustments.

2. Why is irradiance entered in W/m²?

Solar modules are rated against standard irradiance of 1000 W/m². Using actual irradiance lets the tool scale output away from standard test conditions.

3. Why does temperature reduce output?

Most PV modules produce less power as cell temperature rises above 25°C. The temperature coefficient applies that decline to the estimated array output.

4. What is the difference between DC and AC output?

DC output is the module-side power before inversion. AC output includes inverter efficiency and additional performance factors, making it closer to usable delivered energy.

5. What are peak sun hours?

Peak sun hours convert daily solar resource into an equivalent number of full-intensity hours. They are commonly used for fast PV yield estimates.

6. Should I include shading and soiling losses?

Yes. Even modest shading or dirty modules can noticeably reduce real output. Entering realistic values improves planning accuracy and expectation setting.

7. Is this enough for final project financing?

No. This tool is excellent for screening and sizing. Final financing usually needs detailed meteorological data, equipment specs, and professional production modeling.

8. Can I export the results?

Yes. Use the CSV button for spreadsheet-friendly output and the PDF button for a printable summary of the visible result section.