Home automation (“domotics” from the French domotique) is the intelligence layer that connects all your autonomous systems. While not strictly necessary, it can reduce energy consumption by 20–40% and dramatically improve comfort and system management.
| Function | Energy Saving | Comfort Benefit |
|---|---|---|
| Heating scheduling & zone control | 15–25% | Right temperature, right room, right time |
| Lighting automation | 30–50% (of lighting bill) | Automatic, no wasted light |
| Solar surplus management | 20–30% better self-consumption | Maximize use of free energy |
| Water monitoring | 10–20% water savings | Leak detection, usage awareness |
| Appliance scheduling | 10–15% | Run heavy loads during solar peak |
| Ventilation optimization | 10–20% | Air quality without waste |
For our reference home (4,500 kWh electricity, 8,400 kWh heating):
| Without Domotics | With Domotics | Savings |
|---|---|---|
| Electricity: 4,500 kWh | 3,400 kWh | 1,100 kWh (24%) |
| Heating: 8,400 kWh | 6,500 kWh | 1,900 kWh (23%) |
| Water: 200 m³ | 160 m³ | 40 m³ (20%) |
| Annual cost savings | — | €500–900 |
Instead of heating the entire house uniformly, divide it into zones with individual control:
| Zone | Occupied | Target Temp | Unoccupied Temp | Night Temp |
|---|---|---|---|---|
| Living room | Day (08:00–22:00) | 20–21°C | 16°C | 16°C |
| Kitchen | Day (07:00–21:00) | 19–20°C | 16°C | 16°C |
| Bedrooms | Night (21:00–07:00) | 17–18°C | 15°C | 17–18°C |
| Bathroom | Brief (07:00–08:30, 20:00–21:00) | 22°C | 16°C | 16°C |
| Office | Workdays (09:00–18:00) | 20°C | 16°C | 16°C |
Savings from zone control: Reducing temperature by 1°C saves ~7% of heating energy. Dropping unoccupied rooms from 20°C to 16°C saves 25–30% in those rooms.
| Feature | How It Saves | Typical Saving |
|---|---|---|
| Occupancy detection | Stop heating empty rooms | 10–15% |
| Open window detection | Stop heating when window open | 3–5% |
| Weather anticipation | Reduce heating before warm spell | 5–8% |
| Learning schedule | Adapts to your actual patterns | 5–10% |
| Remote control | Reduce heat when away unexpectedly | 3–5% |
| Solution | Components | Cost | Savings |
|---|---|---|---|
| Basic (programmable thermostats) | 4–5 room thermostats | €200–400 | 10–15% |
| Smart (Zigbee/Z-Wave TRVs) | Hub + 8 smart TRVs + sensors | €400–800 | 15–25% |
| Advanced (full zone control) | Controller + motorized valves + sensors | €800–1,500 | 20–30% |
Payback: 1–3 years for most heating automation investments.
The most impactful domotics application for autonomous homes: directing solar surplus to useful loads instead of exporting to grid (at low sell-back rates) or wasting it.
Priority cascade for solar surplus:
| Priority | Load | Power | Control Method |
|---|---|---|---|
| 1 | Battery charging | 0–5,000 W | Automatic (inverter) |
| 2 | Hot water heating | 2,000–3,000 W | Smart relay (SSR) |
| 3 | Heat pump boost | 1,000–2,000 W | Signal to thermostat |
| 4 | Washing machine | 2,000 W | Smart plug, delayed start |
| 5 | Dishwasher | 2,000 W | Smart plug, delayed start |
| 6 | EV charging | 1,400–7,400 W | Smart EVSE |
| 7 | Pool pump/heating | 500–2,000 W | Smart relay |
| 8 | Grid export | Remainder | Automatic (inverter) |
The simplest and most effective surplus routing — use a power diverter:
| Solution | How It Works | Cost |
|---|---|---|
| Commercial diverter (e.g., SolarEdge, myEnergi) | CT clamp monitors grid export; diverts to immersion heater | €300–800 |
| DIY (SSR + energy meter + microcontroller) | ESP32 reads power meter; controls SSR proportionally | €50–100 |
| Home Assistant automation | Software-based; reads inverter API; controls smart relays | €20–50 (relay) |
Impact: Converts 1,000–2,000 kWh/year of would-be export into free hot water. At €0.22/kWh, that’s €220–440/year saved.
Smart plugs (€10–20 each) can delay energy-intensive appliances to solar production hours:
| Appliance | Best Run Time | Annual kWh Shifted |
|---|---|---|
| Washing machine | 11:00–14:00 | 250–400 |
| Dryer (if used) | 11:00–15:00 | 300–500 |
| Dishwasher | 12:00–15:00 | 200–350 |
| Water heater boost | 10:00–16:00 | 1,000–2,000 |
Total kWh shifted to solar: 1,750–3,250 kWh/year — increasing self-consumption from 40% to 70–80%.
| Sensor | Purpose | Cost |
|---|---|---|
| Tank level (ultrasonic) | Know remaining rainwater reserve | €20–40 |
| Flow meter (main supply) | Track daily consumption, detect leaks | €30–60 |
| Soil moisture (garden) | Irrigate only when needed | €15–30 each |
| Rain gauge | Integrate weather into irrigation scheduling | €20–40 |
| Water quality (pH, turbidity) | Monitor filter performance | €50–150 |
A smart irrigation controller connected to soil moisture sensors and weather data:
| Feature | Benefit |
|---|---|
| Soil moisture threshold | Only water when soil drops below 40% field capacity |
| Weather forecast integration | Skip irrigation if rain expected within 24h |
| ET-based scheduling | Calculate actual crop water need from temperature, humidity, wind |
| Zone timing | Different schedules for vegetables, fruit trees, greenhouse |
| Remote monitoring | Check garden status from phone |
Water savings from smart irrigation: 30–50% compared to timer-based systems.
Cost: €100–300 for a complete smart irrigation setup (controller + 4–6 moisture sensors + rain gauge).
| Metric | Sensor/Method | Why It Matters |
|---|---|---|
| Solar production (real-time) | Inverter API | Know your generation |
| Grid import/export | CT clamp on main cable | Track autonomy rate |
| Battery SoC | BMS/inverter API | Manage reserves |
| Per-circuit consumption | Multi-channel CT (e.g., Shelly 3EM) | Identify waste |
| Indoor temperature per room | Zigbee temp sensors | Heating optimization |
| Outdoor temperature + humidity | Weather station | Predict heating/cooling needs |
| Water tank level | Ultrasonic sensor | Plan water usage |
| Gas/LPG usage (if any) | Pulse counter on meter | Track cooking/backup heating |
A well-designed dashboard shows:
| Platform | Type | Cost | Pros | Cons |
|---|---|---|---|---|
| Home Assistant | Self-hosted (Raspberry Pi) | €50–150 (hardware) | Hugely flexible, local control, privacy | Requires technical skill |
| Jeedom | Self-hosted | €50–150 | French, good community | Less modern UI |
| Domoticz | Self-hosted | €50–100 | Lightweight | Smaller ecosystem |
| OpenHAB | Self-hosted | €50–150 | Java-based, very flexible | Steeper learning curve |
| Vendor platforms (Tuya, Shelly) | Cloud-based | Free | Easy setup | Privacy concerns, cloud dependency |
Recommendation: Home Assistant on a Raspberry Pi 4/5 or mini-PC. It integrates with virtually everything, runs locally (no cloud dependency — important for autonomy!), and has excellent energy management dashboards built in.
| Protocol | Range | Power Use | Mesh Network | Devices Available | Best For |
|---|---|---|---|---|---|
| Zigbee | 10–30 m | Very low | Yes | Thousands | Sensors, switches, TRVs |
| Z-Wave | 15–30 m | Very low | Yes | Hundreds | Reliable home automation |
| WiFi | 30–50 m | Moderate | No (mesh routers) | Thousands | Cameras, displays, heavy data |
| LoRa | 2–15 km | Ultra-low | Not typical | Growing | Remote sensors (field, forest) |
| 433 MHz | 100+ m | Ultra-low | No | Many cheap sensors | Weather stations, simple sensors |
| Matter | Variable | Low | Yes (Thread) | Growing rapidly | Future-proof standard |
| Bluetooth LE | 10–30 m | Very low | Yes (BLE Mesh) | Many | Proximity sensors, beacons |
For autonomous homes: Use Zigbee for indoor automation (low power, mesh, large ecosystem) and LoRa for outdoor/remote sensors (garden moisture, forest weather station, water tank level).
| Category | Items | Cost |
|---|---|---|
| Central hub | Raspberry Pi 5 + SSD + case + Home Assistant | €100–150 |
| Zigbee coordinator | USB Zigbee stick (Sonoff ZBDongle-E) | €15–25 |
| Heating | 8 × smart TRVs (Zigbee) | €200–400 |
| Temperature | 6 × room temp/humidity sensors | €60–120 |
| Energy | 3-phase energy monitor (Shelly 3EM) | €80–120 |
| Solar | Inverter integration (usually free via API) | €0 |
| Lighting | 10 × smart bulbs or switches | €100–200 |
| Presence | 3 × motion sensors | €30–60 |
| Water | Tank level sensor + flow meter | €50–100 |
| Garden | 4 × soil moisture sensors + rain gauge | €80–150 |
| Weather | Outdoor weather station | €50–100 |
| Power surplus | 2 × smart relays (hot water, EV) | €30–60 |
| Monitoring | Tablet for dashboard display | €100–200 |
| Total | — | €895–1,685 |
| Item | Cost |
|---|---|
| Electricity (hub + coordinator, always-on) | €10–20 |
| Sensor batteries (CR2032, 1–2 year life) | €10–20 |
| Internet (for remote access, optional) | Already paid |
| Total | €20–40/year |
06:30 - Bathroom TRV boosts to 22°C (motion-triggered or scheduled)
06:45 - Kitchen TRV boosts to 20°C
07:00 - Check solar forecast → if sunny, delay washing machine to 11:00
07:00 - If tank level < 50%, reduce garden irrigation zone 3
07:30 - After shower, bathroom TRV returns to 16°C
08:00 - If nobody home, all zones → setback temperature
10:00 - Solar production exceeds consumption
10:00 - Battery charging begins (automatic)
10:30 - Battery reaches 80% → divert surplus to hot water
11:00 - Hot water reaches 55°C → start washing machine
12:00 - Still surplus → boost heat pump tank temperature to 60°C
13:00 - Surplus declining → stop boost loads, focus on battery
14:00 - Check garden moisture: Zone 1 dry → irrigate for 20 min (using rainwater pump)
Day 1 evening - Battery below 60% → reduce all setpoints by 1°C
Day 1 evening - Notification: "Load wood stove, battery reserve declining"
Day 2 morning - Battery below 30% → disable non-essential loads (dryer, oven timer)
Day 2 morning - Switch to grid import if available, or start generator
Day 3 - Solar forecast improving → resume normal operation
| Investment | Annual Savings | Payback |
|---|---|---|
| Smart thermostats (€400–800) | €200–400 | 2–3 years |
| Energy monitoring (€100–200) | €100–200 (awareness effect) | 1–2 years |
| Surplus routing (€100–300) | €200–440 | 0.5–1.5 years |
| Appliance scheduling (€50–100) | €80–150 | 0.5–1 year |
| Smart irrigation (€100–300) | €50–120 | 2–3 years |
| Total system (€900–1,700) | €630–1,310 | 1–2 years |
Home automation has the fastest payback of any autonomous home investment — often under 2 years. It also makes every other system work more efficiently.
📊 Quick Reference — Domotics Impact:
| Metric | Without Domotics | With Domotics | Improvement |
|---|---|---|---|
| Self-consumption of solar | 35–45% | 70–85% | +25–40% |
| Heating consumption | 8,400 kWh | 6,500 kWh | -23% |
| Electricity consumption | 4,500 kWh | 3,400 kWh | -24% |
| Water consumption | 200 m³ | 160 m³ | -20% |
| Annual cost savings | Baseline | €500–900 | Significant |
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