Home automation = Maximum solar

It’s a fantastic idea to automate your home appliances based on solar production, especially with a grid-tied inverter and no battery, allowing you to maximize self-consumption when you’re away. Home Assistant is perfectly suited for this, and you can grab your home assistant hub from our shop.

Here’s how you can go about setting up such a system, breaking it down into key areas:

1. Integrating Your “”2kW” Grid-Tied Inverter with Home Assistant

To automate based on solar production and export, Home Assistant needs to “see” this data.

• Inverter Integration: Many popular inverters (e.g., Fronius, SolarEdge, Solax, GivEnergy, Growatt, Huawei, Victron, Sunsynk, Deye) have official or community-developed Home Assistant integrations. You’ll need to check the documentation for your specific inverter model against that of the community lists of support.
  • Local API/Modbus: The most robust and recommended way is to integrate directly via the inverter’s local API (if available) or Modbus TCP. This keeps your data local and doesn’t rely on cloud services. Some integrations like “GivTCP” (for GivEnergy) or Modbus integrations for FoxEss/Solax are highly regarded.
    
  • Cloud Integration: Some inverters only offer cloud-based integrations. While simpler to set up, they mean your Home Assistant depends on an internet connection and the inverter manufacturer’s cloud service for data.
  • Dedicated Hardware: For some less-supported inverters, solutions like “Solar Assistant” running on a Raspberry Pi can bridge data via MQTT to Home Assistant, We also build devices to support the integrations and keep the cost low.
    
• Essential Sensors: For the Home Assistant Energy Dashboard and your automations to work correctly, you’ll ideally need three energy sensors (kWh or Wh) and potentially corresponding power sensors (W):
  • Solar Production (W/kWh): The instantaneous power your panels are generating and the total energy produced.
  • Grid Import (W/kWh): The power and energy you’re currently drawing from the grid.
  • Grid Export (W/kWh): The power and energy you’re currently sending back to the grid.
  • Net Consumption Sensor: If your monitoring only provides a single net meter reading (positive for import, negative for export), you might need to create template sensors in Home Assistant to split this into separate import and export sensors, some home meters support coms, some do not.
• Energy Monitoring Devices (if inverter doesn’t provide all data): Devices like Shelly EM or Shelly 3EM (DIN-rail mountable with CT clamps) can measure power consumption at your mains or individual circuits and integrate seamlessly with Home Assistant via MQTT or their local API [2.1].

2. Setting Up Smart Switches for Appliances

To control your dishwasher and washing machine or anything else in your home, you’ll need smart plugs or relays that can handle their power draw and integrate with Home Assistant.

• Smart Plugs with Power Monitoring:
  • Shelly Plug S / Shelly Plus Plug PM: Compact, reliable, and excellent for power monitoring. They integrate locally.
  • Sonoff POW Origin / Sonoff POW Elite: Affordable, often flashable with Tasmota for local control, and include power monitoring.
  • TP-Link Kasa Smart Plugs (e.g., KP115): Many offer energy monitoring and local control.
  • Zigbee/Z-Wave Smart Plugs: Brands like Aqara, Aeotec, and Innr offer power monitoring plugs that integrate via a Zigbee or Z-Wave dongle connected to your Home Assistant hub.
  • RenewSolar: Custom built and off the shelf hardware solutions can offer a wider and more flexible solution than off the shelf items.
    
• Important Considerations:
  • Current Rating: Ensure the smart plug/relay is rated for the maximum current drawn by your appliance (e.g., washing machines and dishwashers can draw significant power). Overloading can be a fire hazard.
    Typically most devices will use around less than 2.5kw, but the switches are also 10amp (2.3kw) some for shorter durations, therefore care needs to take place, if using single point multi switches.
    
  • Appliance State Detection: For better automation, consider adding a door/window sensor to the appliance door or using its power consumption profile to detect if it’s “running” or “finished”. This can be a little more tricky as appliances can vary how they work, note the start and end of cycles.

3. Automations to Read Power and Send Commands

Home Assistant’s automation engine is where the magic happens.

• Solar Optimizer Integration: For advanced solar surplus management, consider the “Solar Optimizer” HACS integration This integration is specifically designed to:
  • Monitor your net instantaneous home consumption (negative if you’re exporting, positive if importing).
  • Monitor your instantaneous PV production.
  • Control equipment based on available solar surplus.
  • Allow you to set maximum run times for appliances.
• Manual Automation Setup (if not using Solar Optimizer):
  • Trigger: Define a trigger based on your solar export or production sensor. For example:
    • platform: numeric_state
    • entity_id: sensor.your_inverter_export_power
    • above: 1000 (e.g., 1000W of export surplus)
    • for: 00:05:00 (for at least 5 minutes to ensure stable surplus)
  • Conditions: Add conditions to refine when the appliance should run:
    • Presence Detection: Use your phone’s location, router presence detection, or motion sensors to determine if you are “not at home.”
    • Appliance State: Ensure the appliance isn’t already running or in a state where it shouldn’t be turned on (e.g., if the door is open).
    • Time Windows: Set specific time windows when the automation is allowed to run (e.g., during daylight hours).
    • Forecast (advanced): See the next section on weather integration.
  • Action: If all triggers and conditions are met, turn on the smart switch connected to your dishwasher/washing machine:
    • service: switch.turn_on
    • target: entity_id: switch.your_dishwasher_smart_plug
  • Turn-Off Automation: Create a corresponding automation to turn off the appliance if the solar surplus drops below a threshold, or if the appliance reports its cycle is complete (if it has that capability or you track it via power consumption).

4. Integrating Live Weather Data for Optimisation

Integrating weather data allows Home Assistant to make more informed decisions, especially for predicting future solar production. This is to address the cycle that you may start and having the solar to finish, or time shifting devices.

• Solar Forecast Integrations:
  • Forecast.Solar: A popular integration that predicts solar production based on your location, panel orientation, and historical weather data. While sometimes under-estimated, it provides a good baseline.
  • Solcast: Many users find Solcast more accurate for solar forecasting.
  • Open Meteo (Irradiance Forecast): Can be used to convert irradiance forecasts into PV output predictions.
• Using Weather Data in Automations:
  • Conditions for Activation: Before turning on a high-power appliance, you could add a condition that checks:
    • sensor.solar_forecast_power_next_hour is above: 1500 (to ensure enough future power).
    • sensor.weather_cloud_cover is below: 50 (to avoid starting on a heavily overcast day).
  • “Peak Solar Window” Helper: Create a Home Assistant helper (e.g., input_boolean) that turns on during your predicted peak solar hours based on forecast data. Use this as a condition for your appliance automations.
  • Time-Based Adjustments: If a weather forecast predicts a cloudy afternoon, your automation could prioritize starting the dishwasher earlier in the day when the morning sun is strongest.

5. Cooling, Heating, and Hot Water Integration

Extending this concept to heating and cooling can significantly reduce your energy bills.

• Hot Water:
  • Smart Immersion Heater Controllers/Relays: Many smart relays (e.g., Sonoff POW Elite paired with a Solid State Relay (SSR) for high power) can directly control your immersion heater [6.1].
  • Dedicated Solar Diverters: Devices like Eddi or iBoost are specifically designed to divert surplus solar power directly to an immersion heater, often by varying the power delivered [6.2]. While more expensive, they are highly efficient.
  • Automation Logic:
    • Trigger: Solar export above: [threshold] (e.g., 2000W) for a set duration.
    • Condition: Hot water tank temperature below: [desired_temp] (requires a temperature sensor in your hot water tank, often integrated with a smart thermostat or a dedicated temperature sensor like a DS18B20 with ESPHome).
    • Action: Turn on immersion heater.
    • Turn-Off: When solar export drops below threshold, or desired water temperature is reached.
• Cooling (Air Conditioning):
  • Smart Thermostats: Integrate smart thermostats (e.g., Ecobee, Nest, Tado, Shelly TRV) with Home Assistant. Many have native integrations.
  • Smart AC Controllers: For mini-split or window AC units, smart controllers (e.g., Sensibo, Tado Smart AC Control) can integrate with Home Assistant.
  • Automation Logic:
    • Trigger: Solar production above: [threshold] and interior temperature above: [setpoint].
    • Condition: Home occupancy (e.g., someone is home or expected to arrive soon).
    • Action: Turn on AC or adjust thermostat setpoint lower.
    • Prediction: Use solar forecast data to pre-cool your home during peak solar production hours, reducing the need for grid power later in the day.
• Heating:
  • Smart Thermostats/TRVs: Similar to cooling, integrate smart thermostats or smart radiator valves (TRVs) with Home Assistant.
  • Boiler Control: For central heating, you can use smart relays to control your boiler’s call for heat.
  • Automation Logic:
    • Trigger: Solar production above: [threshold] and interior temperature below: [setpoint].
    • Condition: Home occupancy.
    • Action: Turn on heating or adjust thermostat setpoint higher.
    • Pre-heating: Use solar forecast to pre-heat your home during sunny periods, leveraging free energy.

Getting Started

1. Install Home Assistant: If you haven’t already, set up Home Assistant on a Raspberry Pi, mini PC, or in a virtual machine. We have these ready in the shop
2. Identify Inverter Integration: Find the relevant integration for your inverter.
3. Acquire Smart Switches: Purchase smart plugs or relays suitable for your appliances.
4. Install Energy Monitoring: Ensure you have sensors for solar production, grid import, and grid export.
5. Start Simple: Begin with one appliance and a basic automation, then gradually add complexity (weather data, more appliances, heating/cooling).
6. Community Resources: The Home Assistant community forums and Reddit (r/homeassistant) are invaluable resources for specific integration help and automation examples. Many users share their YAML code for complex setups.

By leveraging Home Assistant, you can create a highly efficient and automated home that intelligently uses your solar power, saving you money and maximizing your renewable energy investment. When you have solar without a battery, grid tied exports power that you may not be paid for, after all you may want to use the power, and you only save with grid tied solar when you use that solar power when its available.

If you buy your lenovo home assistant hub from us, its installed with home assistant and the system configured to work well for solar and automations, its a good base and green as we supply refurbished units.