Solar siting, measured on the ground
Measure the sun
where you actually stand.
Point your phone at a roof, balcony, garden or field. SunMeasure tracks the sun's path, detects the trees and buildings that shade it, and rates how good the spot truly is. The result is a clean PDF. Free. No install. No sign-up.
The problem
Two roofs on the same street.
One pays off in six years. One never does.
Solar maps see the rooftop. They don't see the oak to the east, the hill to the north, or the neighbour's gable stealing your winter afternoons. The difference is shade. And shade is local, hourly and seasonal. It is also the single most underestimated reason solar underperforms.
A single tree can cost 20-40% of a year's yield, and as little as 5% shading can throttle a whole series string. Sources: Aurora Solar (single tree); Fraunhofer CSP (5% module loss)
How it works
Three marks on the dial.
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01
Stand on the spot
Open sunmeasure.com in your browser. No app store, no account, just the place you want to measure.
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02
Sweep the sky
Slowly pan your phone across the horizon. AR maps every tree, ridge and rooftop that can block the sun around you.
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03
Read the report
Get sun-hours by season, a yield rating out of 100, your worst shading culprits, and the best panel tilt. All as a PDF.
The scan
Your phone draws the skyline that steals your sun.
As you sweep, SunMeasure plots a shadow horizon: the exact altitude of every tree, ridge and rooftop around your spot. Where the sun's arc dips behind that line, you lose light. We compute it minute by minute, month by month.
- Astronomical sun path for your exact latitude and date
- On-site obstruction profile, not a satellite guess
- Direct, diffuse and seasonal sun separated out
- Cross-checked against terrain data, so a rushed sweep still works
Good spot
ADVICE Heavy morning shade from the east. A west-facing tilt recovers more of the afternoon. Est. +9% yield vs due south here.
The output
Everything about your spot, on one page you can act on.
Every scan becomes a clean report: a solar score out of 100, sun-hours per season, your worst shading culprits, expected kWh per square metre, and a recommended panel orientation and tilt. It is the kind of artifact you can hand to an installer, or use to justify a balcony-solar purchase.
When a spot is poor, we tell you plainly. A straight answer is the whole point.
The method
Satellite irradiance, meet the shadow on your ground.
We start with location solar maps: kWh per square metre for your region, from official sources like PVGIS. Then we subtract reality: the hours your spot spends in shade. The combination is the only honest answer to "is this spot worth it?"
- "No direct sun until about 10:40 in winter, a tree sits due east."
- "Only summer sun, you're tucked on the north side of a hill."
- "Open to the south with nothing tall nearby, strong most of the year."
Start at zero
Your first report is free, and it stays free.
No account, no card, no install. Just point your phone and scan. Your spot, measured, in about a minute.
Free report
€0
Free, and it still does real work.
- Full AR scan of one spot
- Solar score out of 100 & plain-language verdict
- Seasonal sun-hours overview
- Top shading causes identified
- Basic orientation advice · single-page PDF
No sign-up. Instant.
A premium plan may arrive in the future. For now, the free report is the whole product.
The fine print, in daylight
Questions, answered straight.
Do I need to install anything?
No. SunMeasure runs in your phone browser. There is no app to download and no account to create. You just open the page and start.
Do you store my camera video?
The scan is processed on your device. Only the computed shadow horizon is sent to a small backend that renders your PDF. The raw video is not kept.
How accurate is it?
Sun position is astronomical and exact. Obstruction accuracy depends on how carefully you sweep. The app guides you, and cross-checks against terrain data so a rushed scan still gets a sensible horizon.
Where does it work?
Anywhere with daylight. Irradiance data is strongest across the EU using official sources such as PVGIS, Global Solar Atlas and DWD, and is expanding to more regions.
Which phones are supported?
Any modern smartphone with a camera and a current browser. No special hardware, no calibration kit, no €2,000 instrument.
Data sources: PVGIS (EU JRC) · Global Solar Atlas (World Bank / Solargis) · Copernicus CAMS · DWD · NASA POWER
From the notebook
Field guides on sun, shade and siting.
The sun's already moving.
Find out what your spot really gets.
Free, instant, in your browser.
Scan a spot, free report