Outdoor map tool
Solar Panel Shading and Sun-Path Checker
SunCarta provides an early visual screen for obvious obstruction risks around a proposed solar location. It connects sun direction and altitude to the nearby objects you model, without pretending to replace bankable energy-yield software.
- Cost
- Free
- Account
- Not required
- Project data
- Browser-local
Loading the global map…
Click once to move the receiving point.
What this tool calculates
- Solar position for representative dates and times
- Whether a modeled obstacle crosses the sun ray to the selected point
- Plan-view shadow length and direction
- A coarse direct-sun duration suitable for initial comparisons
How to use it
- 01
Place the array point
Use the approximate roof or ground location, not only the property centroid.
- 02
Model the horizon
Add nearby buildings, parapets, walls and mature trees using conservative verified heights.
- 03
Check representative seasons
Winter usually creates longer shadows. Compare multiple dates and inspect the hours when production matters.
How to read the result
Screening result
A clear result suggests fewer obvious local obstructions; it does not quantify annual kilowatt-hours or electrical losses.
Conservative modeling
When height is uncertain, test a plausible low and high value. A decision that changes across that range needs better data.
Limits you should know
- Roof tilt, panel azimuth, row-to-row shading and module electronics are not modeled.
- No weather, irradiance, soiling or energy-yield calculation is included.
- Use professional site assessment and appropriate design software before installation.
Questions about this calculator
Can this replace a solar installer’s shade analysis?
No. It is an early screening and comparison tool. Detailed design requires verified geometry, irradiance data and equipment-specific modeling.
Which date gives the longest shadows?
Near the local winter solstice the midday sun is generally lowest, but morning and afternoon geometry still depends on the obstacle’s direction.
Methodology version 1.1 · Reviewed August 8, 2026