The Intelligent Companion for your Fronius Gen24 Inverter.
Stop guessing. Start optimizing. Track your ROI in real-time.
Important
Hardware requirement: SunFlow is built specifically for the Fronius Solar API and targets the Fronius Gen24 (Symo/Primo) inverter family. If you don't have a Fronius Gen24 inverter with Solar API enabled, SunFlow will not be able to read live data (other inverter brands/APIs are currently not supported).
SunFlow is not just another monitoring tool. While manufacturer apps are great for checking if your system is running, SunFlow is designed for the system owner who wants to maximize value.
It combines real-time high-speed monitoring (direct local connection) with financial intelligence. SunFlow calculates exactly when your system will pay for itself based on your specific installation costs and electricity tariffs.
Most importantly, it features a 24/7 Smart Energy Assistant running on your server. It combines solar forecasts with your battery state to notify you exactly when to run your heavy appliances to maximize self-consumption—even if you don't have the dashboard open.
Don't just watch the power flow—act on it.
- Server-Side Intelligence: The backend continuously monitors surplus, battery SOC, and solar forecasts (Solcast).
- "Battery Safe" Logic: The system calculates if there is enough sun left to fill your battery and run your washing machine. If not, it advises conserving energy for the night.
- Appliance Library: Add your own devices (Sauna, EV, Dishwasher) with their specific power profiles to get tailored advice.
Stay informed wherever you are.
- Proactive Suggestions: Get a ping on Discord when it's the perfect time to run appliances.
- Safety Alerts: Instant notifications for Inverter Errors, Battery Empty, or Battery Full events.
- Hysteresis Logic: Intelligent alerting that prevents "notification bounce" by requiring state changes before re-notifying (e.g., dropping below 95% SoC before sending a new "Full" alert).
- Health Warnings: Get alerted if your Battery SOH (State of Health) drops below a defined threshold.
Experiment with your system before spending a dime.
- Scenario Planning: Simulate adding more PV power (+200%) and/or a larger battery (up to 30kWh).
- Recommendation Focus: Choose between ROI (payback) and Autonomy (grid independence). ROI mode respects your selected payback horizon.
- Coupled ROI: Shows the battery’s incremental benefit (PV-only → PV+Battery) so PV ↔ battery dependencies are visible (and combined PV+battery payback stays within your horizon).
- Historical Baseline (Correctness): Uses your real hourly import/export where available so the “no-upgrade” baseline matches reality.
- Uses Available Signals: If present, the simulator uses measured battery SoC and charge/discharge flows to improve realism (start state + limits/efficiency).
- Confidence & Coverage: Shows how much of the selected timeframe contains usable hourly data, and which signals (grid/battery) were available.
- Battery Sizing Hint: Optionally suggests a “best value” battery add-on size based on your own history.
See if a dynamic market-based tariff would have been cheaper for your household.
- Fixed vs Dynamic: Compares your historic net cost using your configured fixed tariff vs aWATTar hourly market prices.
- Real Import/Export: Uses your actual hourly grid import/export from the database (export is still credited at your configured feed-in tariff).
- All-in Assumptions: Add a surcharge and VAT to approximate your full retail price (aWATTar provides exchange prices).
- Flexible Range: Pick 7/30/180/365 days or a custom date range, with coverage stats shown.
- SOH Tracking: Automatically estimates your Battery's State of Health and Efficiency based on real charge/discharge cycles over time.
- Cycle Counter: Tracks the estimated number of full cycles your battery has completed.
- Degradation Monitoring: Visualizes capacity loss to help you claim warranty if needed.
Solar is an investment. Track it like one.
- Amortization Countdown: See the exact date your system breaks even.
- Hybrid Calibration: Automatically syncs manual offsets with database-calculated totals for absolute accuracy.
- Granular Tariffs: Supports changing energy prices over time (e.g., price hikes in 2024).
- CAPEX & OPEX: Log installation costs, maintenance fees, or battery upgrades.
- History Importer: Import Home Assistant or Fronius CSV data. The system automatically "explodes" daily totals into hourly profiles for detailed chart resolution.
- Self-hosted Data: Your data lives in a local SQLite database. No cloud delays, no data retention limits.
- Efficiency Metrics: Track your Autonomy (Grid Independence) and Self-Consumption ratio over days, months, or years.
- Interactive Charts: Zoomable, beautiful charts for Production, Load, Grid, and Battery.
| Live Dashboard | Analysis & Finances |
|---|---|
 |
 |
| Real-time power flow & Smart Suggestions | ROI Tracking & Long-term History |
SunFlow is built as a lightweight Docker container. You can run it on a Raspberry Pi, a Synology NAS, or any server.
- Fronius Gen24 Inverter (Symo/Primo) with
Solar APIenabled.- Enable via Inverter Web Interface: Communication > Solar API > Enable.
- Docker installed on your machine.
Tip
For production, consider pinning a version tag (e.g. ghcr.io/robotnikz/sunflow:<version>) so updates/rollbacks are explicit.
Use the included docker-compose.yml in this repository (or create your own):
version: '3.8'
services:
sunflow:
# Uses the public image from GitHub Container Registry
image: ghcr.io/robotnikz/sunflow:latest
container_name: sunflow
restart: unless-stopped
ports:
- "3000:3000"
volumes:
# Persist database and config
# Data will be stored in a 'sunflow-data' folder next to this file
- ./sunflow-data:/app/data
environment:
- TZ=Europe/Berlin # Set your Timezone!Run it:
docker compose up -dImportant
Upgrade safety (data/history): keep your ./sunflow-data directory when updating. If you delete or change this mount, SunFlow will start with an empty database.
Tip
For upgrades, backups, rollback and troubleshooting, see docs/OPERATIONS.md.
docker run -d \
-p 3000:3000 \
# Recommended (compat): bind mount to a host folder
-v "$(pwd)/sunflow-data:/app/data" \
-e TZ=Europe/Berlin \
--name sunflow \
ghcr.io/robotnikz/sunflow:latestOnce running, access the dashboard at http://localhost:3000.
- Click the Settings Icon (top right).
- General: Enter your Inverter IP (e.g.,
192.168.1.50) and System Capacity. - Notifications: Add your Discord Webhook URL to enable push notifications for Smart Suggestions and Alerts.
- Forecasting: Add your Solcast API Key (Free Tier) to enable the "Battery Safe" calculation logic.
- Tariffs & Expenses: Add your grid costs and installation expenses to activate the ROI widget.
- Appliances: Configure your heavy consumers (Watts & Duration).
For day-2 ops (backup/restore, upgrades, common issues), see docs/OPERATIONS.md.
SunFlow is intended for self-hosting on a trusted network. If you expose it beyond your LAN, put it behind a reverse proxy with TLS and authentication.
- Optional admin token (recommended): set
SUNFLOW_ADMIN_TOKENand call write endpoints withAuthorization: Bearer <token>. - CORS allowlist (recommended): set
CORS_ORIGINto a comma-separated list of allowed browser origins (prod defaults to no cross-origin). - Reverse proxy setups: set
TRUST_PROXY=1so rate limiting and IP logic work correctly.
For details and additional recommendations see docs/AUDIT.md.
Practical checklist for self-hosting: SECURITY.md.
Operations runbook (backup/restore, upgrades, troubleshooting): docs/OPERATIONS.md.
See CONTRIBUTING.md for developer setup, testing, and PR guidelines.
- Test strategy & scenarios: docs/TESTPLAN.md
- Quick manual UI regression checklist: docs/UX_CHECKLIST.md