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Solar Potential Calculator

Pick a point on the map to set where your solar panels will be installed.
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Already Have Solar Panels?

Get a real 7-day hourly forecast of your solar generation powered by Open-Meteo weather data. Simulate which devices you can power — in real time.

Enter the total capacity of your installed solar panels

Location

Location is taken from the map above

How It Works

  • Compute extraterrestrial radiation H₀ based on your latitude and date.
  • Apply transmissivity τ to estimate Global Horizontal Irradiance (GHI).
  • Account for panel tilt gain by setting the tilt angle approximately equal to the latitude for optimal annual yield.
  • Multiply by Performance Ratio (PR) and roof area for annual kWh.
  • Derive CO₂ avoided and cost savings.
How it works visual steps
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About This Tool

This is a fast, simple tool for a first assessment of your roof’s solar potential and CO₂ savings. Use it to get an instant estimate before diving deeper.

Example Use Cases:

  • Quickly gauge annual kWh before contacting installers
  • Compare different roof areas or tilt scenarios
  • Estimate CO₂ reduction for sustainability reports
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Resources & FAQ

Glossary

  • kWp: Peak power rating of a solar system.
  • GHI: Global Horizontal Irradiance.
  • PR: Performance Ratio.
  • τ: Atmospheric transmissivity.

FAQ

How accurate is this estimate?
The estimate is typically accurate within ±20% for most locations and roof types.
Can I use this tool for any country?
Yes, you can estimate solar yield for any location by picking a point on the map.
What data do I need to use the calculator?
You need your roof area, location, and optionally your annual electricity consumption.
Does this tool consider shading or obstacles?
No, it assumes an unshaded, south-facing roof for best results. For more precise results, consult a professional installer.
How do I interpret the CO₂ avoided value?
It shows the estimated annual reduction in carbon emissions if you install solar panels, based on your local grid's average emissions.

Methodology

  • Compute daily extraterrestrial radiation (H₀) using the solar constant, day of year, declination and sunset hour angle.
  • Apply atmospheric transmissivity (τ) to derive Global Horizontal Irradiance (GHI) in kWh/m²/day.
  • Adjust for panel tilt gain by setting the tilt angle approximately equal to the latitude for optimal annual yield.
  • Multiply GHI by Performance Ratio (PR) and system capacity (kWp) to get monthly and annual yield.
  • Estimate CO₂ avoided using 0.5 kgCO₂/kWh.
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