Solar Energy Monitoring System

Challenge

The client had a 10 kWp solar installation with a Victron SmartSolar MPPT controller but zero telemetry. They wanted to know daily production figures and receive SMS alerts when output drops below seasonal norms — without buying an expensive manufacturer monitoring system.

Solution

Raspberry Pi 4 running Venus OS communicates with the MPPT controller via Modbus TCP/IP and collects production, battery voltage and load data. Node-RED aggregates readings every 60 seconds and sends them to InfluxDB running on a local NAS. Grafana serves a dashboard with daily, weekly and annual charts.

SMS alerts via Twilio: if hourly production drops below a configurable threshold (per month), the system sends an SMS with the current value and 24-hour average. Node-RED handles anti-spam logic — maximum 2 alerts per day.

Results

• 24/7 monitoring with no paid cloud service
• Grafana data read latency: < 2s
• 3-year data history on local NAS (< 500 MB/year in InfluxDB)
• Client detected panel soiling from data anomalies — would never have noticed without the system