Live power flow (solar, battery, grid, load), state of charge, battery voltage and temperature, inverter temperature, error and fault codes, charge/discharge schedule, firmware version, and aggregate energy counters. Read from the inverter's standard local Modbus port — the same data the GivEnergy app pulls from the cloud.
How it works
Local agent. UK cloud. Real engineers.
Sentinel is three things working together: a tiny program on your network that talks to your inverter, a small UK cloud that watches for faults, and the real-life engineers at Solar Tech Support who fix what needs fixing.
Setup
Four steps. Fifteen minutes. Then Sentinel just stays on watch.
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Install Run the free agent
Tiny binary on any PC you leave on, or a £75 Raspberry Pi kit from The Pi Hut. Pre-built image — flash, plug in, done.
About 15 minutes · no command line
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Pair Connect it to sentinelapp.solar
Open the dashboard, enter the one-time code shown by the agent. Encrypted outbound connection only — nothing to forward on your router.
About 30 seconds
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Watch See your system, live
Power flow, battery, solar, grid, history — in your browser. Mobile-friendly. Free forever on Watch, with self-serve control on £1/mo Guard.
From the moment it pairs
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Stand guard Sentinel watches for faults
Email alerts the moment we spot trouble. If something needs fixing, an STS engineer rings you with the diagnosis already in hand.
Ongoing · zero effort from you
What we look for
The faults Sentinel catches before you notice them.
A non-exhaustive list — these are the patterns our engineers see go wrong most often on GivEnergy systems in the field.
Battery not charging
Solar is generating, the charge slot is active, but state of charge isn't rising. Common when a BMS contactor weakens or a charge schedule has drifted.
Battery not discharging
No solar, load is present, SoC well above reserve, no discharge slot blocking — but the inverter isn't drawing from the battery. Classic comms-loss symptom.
Fault codes thrown
We map the inverter's holding-register fault codes to plain-English categories — "battery comms loss", "grid out-of-range", "BMS isolation fault" — and tell you what they mean.
Temperature drift
Battery or inverter temperature climbing outside the safe envelope. Early-warning for degradation and end-of-life cell failure.
Grid excursions
Voltage or frequency outside the G98/G99 envelope. Could be DNO side, could be your inverter — Sentinel flags the trend so you know which.
Known-buggy firmware
We maintain a list of firmware versions with known issues (charge-slot resets, EPS misbehaviour, etc.) and warn you when yours is on it.
Under the hood
What it does, what it doesn't, what's where
A small summary (a few hundred bytes per snapshot) — power values, fault flags, energy totals. No personal data, no audio, no video, no LAN topology. You can run Watch entirely offline if you prefer; the local dashboard still works.
A rule engine on our cloud evaluates each snapshot against a library of fault patterns: battery not charging when it should be, fault codes thrown in the holding registers, voltage / frequency excursions, temperature drift, firmware versions on the known-buggy list, slow degradation curves. When a rule fires, you get an email; our triage queue surfaces it to an STS engineer.
Outbound TLS only — no inbound ports opened on your router. Per-device mTLS certificates issued at pairing, rotated annually. Write commands require you to arm a one-hour engineer-access window from your dashboard; the agent refuses writes outside that window. Every action is logged immutably and visible to you.
Yes. From the dashboard, "Export → CSV" gives you every snapshot the agent has sent, at native resolution. Open in Excel, Google Sheets, Home Assistant, Grafana — wherever. Your data stays yours.
Try it free
Install Sentinel in 15 minutes.
No card needed. No GivEnergy cloud account needed. Just a PC or Pi on the same network as your inverter.
- Free Watch tier — forever
- Read-only by default
- Works behind any home router
- Backed by Solar Tech Support