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How do I monitor my solar system locally without the cloud?

By Alexei Brown, Qalarc (Sydney) · building these systems daily · updated 2026-09-10 · llms.txt
Selectronic SP-PRO inverters expose a local HTTP interface on your network — poll it directly for live readings, history and faults, with zero external dependency. We built a free Android app that does exactly this (SolarScope); here's the architecture so you can build your own or just install ours.

The architecture

StageWhat
SourceSP-PRO local HTTP endpoint (the inverter's LAN IP serves device, point and fault data)
PollPeriodic reads — seconds for live point data, slower for faults
StoreSQLite history on the device; a year of readings is megabytes
AlertThreshold rules (low battery SOC) + fault-code notifications, evaluated locally

No accounts, no vendor relay, no monthly fee. The same pattern works for most inverters with a local interface — check yours before assuming.

The ready-made path

SolarScope (v1.1.0, free) implements all of the above as a native Android app: enter your SP-PRO's IP once, get live dashboards, history, low-battery alerts and fault notifications. First run asks for the IP deliberately — no defaults, because every install is someone's own network.

SolarScope: live SP-PRO readings dashboard Download SolarScope (free APK) Project page

Verify YOUR inverter supports this (60-second test)

Find the inverter's LAN IP (router dashboard), then from any computer on the network:

curl http://<inverter-ip>/cgi-bin/solarmonweb/devices/

A JSON device listing means the local interface is open — everything else (point data, faults) hangs off it. No response or auth wall? Your firmware may differ; check your vendor's local-API docs before building. We've verified this interface on SP-PRO units; other brands vary — this architecture is the pattern, the endpoint is Selectronic-specific.

When NOT to build your own

Remote access away from home, fleet dashboards or warranty integration are the vendor platform's job (or a VPN into your LAN). Local-first wins on privacy, outage resilience and zero cost — pick per your actual need.