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HoriSol
HoriSol

Understand shading. Calculate yield.

HoriSol is an iOS app that measures the horizon line at your balcony using camera and compass, and calculates a balcony solar system's annual yield in kWh, its payback period, and its CO₂ savings.

On the App Store How it works
Results screen with annual yield 623 kWh (±10%), payback 3.6 years, savings, CO₂ saved, and yield-by-month chart

What HoriSol does

  1. Capture shading

    Three photos per orientation — HoriSol measures the horizon with camera and compass and detects obstacles like buildings or trees. You confirm the horizon line with your finger.

  2. Compute annual yield

    Built on NOAA solar math and your exact location, HoriSol simulates the sun's path hour by hour and quantifies the shading loss precisely.

  3. Economics

    Payback period, 20-year ROI, CO₂ saved. HoriSol tells you whether your balcony solar pays off at this specific spot.

  4. Private & offline

    All computation runs locally on your device. No cloud, no accounts, no ad tracking — anonymous usage statistics only if you actively opt in.

A look inside the app

  • Results screen with annual yield 623 kWh (±10%), payback 3.6 years, savings, CO₂ saved, and yield-by-month chart
    Your result — in 2 minutes
  • Camera view of the shading measurement: aim marker and circle guide the shot, photo 3 of 5
    Real shading — you photograph the horizon.
  • Horizon photo with the horizon line drawn in orange and the sun path in blue
    Detected shading — honestly factored in.
  • Location step with map, address search, and a pin placed on the city
    Your location — real sun data.
  • Panel step with rotary ring for orientation (90° east) and a slider for tilt
    East-West setup? No problem.
  • Consumption step with appliance options and a load-curve chart compared to the standard profile
    Your actual consumption matters.

Why HoriSol

Balcony solar has become affordable — but in many spots shading silently eats most of the expected yield. Until now there were only rough rules of thumb. HoriSol turns guesswork into actual measurement, in 2 minutes, with the phone you already carry.

Documentation

How HoriSol works under the hood.

Open docs