FAQ
Is my data sent to a server?
Your inputs, photos, and results stay on your device — all computation runs locally, there is no cloud and no accounts. For solar data, HoriSol queries public solar databases (PVGIS, NREL PVWatts, NASA POWER); only coordinates are transmitted, no profile and no identifier. There is no ad tracking. Optionally — and only if you actively consent — the app sends anonymous usage statistics. Details in the privacy policy.
What does HoriSol cost?
The core feature — measurement, yield calculation, result — is free. Extras such as the detailed PDF report or multiple saved configurations are part of HoriSol Premium: a one-time purchase, no subscription.
How accurate is the measurement?
Accuracy depends on your device’s compass calibration. In practice, the computed yields are within ±10% of the real value — significantly more accurate than any rule of thumb.
Does HoriSol work in winter?
Yes. HoriSol simulates the whole year, regardless of when you measure. The only caveat is that the horizon profile must remain stable (e.g. trees shed leaves in winter — a known limitation).
Do I need an iPhone Pro with LiDAR?
No. A regular smartphone is enough. LiDAR could be leveraged in a later version for even more precise measurements.
Your question isn’t covered? Reach out on the support page — happy to help.