Energy saving automations in Home Assistant

Powering Down Smart: A Practical Guide to Energy-Saving Automations in Home Assistant

Our smart homes can be more than just convenient. In an era of rising energy costs and growing environmental awareness, they can be conscientious. Home Assistant (HA), with its unparalleled flexibility and local-first ethos, is the perfect platform to surpass manual “off” switches. It helps implement intelligent, context-aware energy conservation. This guide will introduce you to the principles. It will show you practical automations and share pro-tips to turn your HA setup into a silent, efficient energy manager.

Why Automate Energy Savings?

Manual effort is inconsistent. Automations work on triggers, conditions, and actions that are always “on,” responding instantly to real-world changes. The goals are clear:

• Reduce Waste: Remove “vampire” standby power and make sure devices run only when needed.
• Shift Load: Use high-power devices (like EV chargers, dishwashers) during off-peak tariff periods.
• Optimize Comfort/Efficiency Balance: Adjust heating/cooling based on occupancy, windows, and external weather, not just a fixed schedule.
• Gain Awareness: Integrate with HA’s Energy Dashboard to track the impact of your automations.

Prerequisites: Laying the Foundation

Before writing automations, make sure your foundation is solid:

1. The Energy Dashboard: Set up this first (Settings > Dashboards > Energy). Add your main grid meter, solar production, and key devices (HVAC, EV charger). This is your mission control for measuring success.
2. Reliable Sensors: You need data. Key sensors include:
   • Presence/Occupancy: device_tracker (phone GPS),  binary_sensor (motion, door/window opens).
   • Environmental: sensor for temperature, humidity, CO2, particulate matter.
   • Power: Smart plugs with energy monitoring (e.g., TP-Link Kasa, Shelly Plug) or a whole-home monitor like the Shelly EM.
3. Integrations: Make sure devices are properly integrated. For custom devices, ESPHome is a powerful, local choice for adding energy monitoring.

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4 Practical, High-Impact Automations (with YAML)

Let’s dive into actionable automations. These examples assume you have the necessary sensors and entities.

1. The “Heater/AC Zombie Killer”

Problem: Space heaters, electric blankets, or AC units left running in empty rooms. Solution: A two-part automation: turn off after inactivity, and prevent turning on if a window is open.

alias: "Climate - Turn Off Heater After No Motion"
trigger:
  - platform: state
    entity_id: binary_sensor.living_room_motion
    to: "off"
    for: "00:30:00" # 30 minutes of no motion
condition:
  - condition: state
    entity_id: climate.living_room_heater
    state: "heat"
action:
  - service: climate.turn_off
    target:
      entity_id: climate.living_room_heater
mode: restart

alias: "Climate - Prevent Heater With Open Window"
trigger:
  - platform: state
    entity_id: binary_sensor.living_room_window
    to: "on"
condition:
  - condition: state
    entity_id: climate.living_room_heater
    state: "heat"
action:
  - service: climate.turn_off
    target:
      entity_id: climate.living_room_heater
  - service: notify.mobile_app_my_phone
    data:
      message: "Heater turned off because a window was opened!"
mode: single

Tip: Use for: in triggers for de-bouncing. The restart mode on the first automation means the 30-minute timer resets if motion is detected again.

2. Adaptive Lighting with Lux & Occupancy

Problem: Lights on full blast during sunny afternoons or in unoccupied rooms. Solution: Use a combination of a light sensor and occupancy.

alias: "Lighting - Adaptive Brightness (Kitchen)"
trigger:
  - platform: state
    entity_id: binary_sensor.kitchen_occupancy
    to: "on"
  - platform: state
    entity_id: sensor.kitchen_lux
condition:
  # Only adjust if lights are actually on (avoid turning on）
  - condition: state
    entity_id: light.kitchen_pendants
    state: "on"
action:
  - service: light.turn_on
    target:
      entity_id: light.kitchen_pendants
    data:
      # Brightness is a percentage (0-100) or 0-255.
      # Map lux (0-1000) to brightness (30%-100%).
      # You can use templates for more complex mappings.
      brightness_pct: >
        {{ [
          30,  # Minimum brightness
          (state_attr('sensor.kitchen_lux', 'state') | float / 1000 * 70) + 30
        ] | min | max(30, 100) }}
mode: single

Tip: This uses a simple inline template. For better performance, create a template sensor (via template: integration in configuration.yaml) that calculates the target brightness and reference that sensor in your automation.

3. Off-Peak Appliance Scheduler (Dishwasher/Washing Machine)

Problem: Running high-wattage appliances during expensive peak grid hours. Solution: Use your utility’s time-based tariff or a dynamic electricity price sensor (if available from your integration).

alias: "Appliance - Delay Start to Off-Peak"
trigger:
  - platform: state
    entity_id: input_boolean.dishwasher_ready
    to: "on"
condition:
  # Check current time against off-peak window (e.g., 10 PM - 6 AM)
  - condition: time
    after: "22:00:00"
    before: "06:00:00"
  # Ensure we're not already in a delayed start period
  - condition: state
    entity_id: input_boolean.dishwasher_delayed
    state: "off"
action:
  - service: input_boolean.turn_on
    target:
      entity_id: input_boolean.dishwasher_delayed
  - service: notify.mobile_app_my_phone
    data:
      message: "Dishwasher will start at 10:00 PM to use off-peak rates."
  # You would then have a separate time-triggered automation at 22:00
  # that checks `input_boolean.dishwasher_ready` and starts the machine.
mode: single

Tip: The input_boolean acts as a flag. Create a second simple time automation at 22:00 that checks if  dishwasher_ready and  dishwasher_delayed are both on, then triggers the actual start (switch.turn_on for your dishwasher’s power).

4. “Nobody Home” Eco Mode

Problem: The house maintains “away” comfort levels even when everyone is gone for hours. Solution: A master automation triggered by a group of people’s absence.

alias: "House - Away Mode - HVAC & Media"
trigger:
  - platform: state
    entity_id: group.all_household
    to: "not_home"
    for: "00:15:00" # 15 min grace period
action:
  - service: climate.set_preset_mode
    target:
      entity_id: climate.all_climate_devices
    data:
      preset_mode: "away" # Or a custom "eco" preset
  - service: switch.turn_off
    target:
      entity_id: group.all_media_switches
  - service: light.turn_off
    target:
      entity_id: group.all_lights
mode: restart # If someone returns, this automation cancels and resets.

alias: "House - Return from Away"
trigger:
  - platform: state
    entity_id: group.all_household
    to: "home"
condition:
  - condition: state
    entity_id: input_boolean.away_mode_active
    state: "on"
action:
  - service: input_boolean.turn_off
    target:
      entity_id: input_boolean.away_mode_active
  - service: climate.set_preset_mode
    target:
      entity_id: climate.all_climate_devices
    data:
      preset_mode: "home"
mode: restart

Tip: Create group.all_household by combining all your device_tracker entities. Use the for: parameter to avoid false trips from someone briefly stepping out.

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Advanced Strategies & Pro Tips

1. Leverage the utility_meter Integration: This is essential for time-of-use tariffs. Create sensors like sensor.electricity_peak, sensor.electricity_offpeak, sensor.electricity_solar that track consumption in those periods. Your automations can then reference these.
2. Predict with Weather & Forecast: Integrate your local weather (weather integration or Met.no). An automation can pre-cool or pre-heat your house before a predicted hot/cold snap, avoiding expensive peak-hour runtimes.
3. Use wait_template for Sequencing: Need to start the dryer only after the washer finishes? Use a wait_template in a script or automation to pause execution until a condition (e.g., sensor.washer_power < 5W) is met.
4. Template the Logic: For complex decisions, create a template binary sensor or template sensor. Example: binary_sensor.hvac_should_run that returns on only if (occupancy == on) AND (window == closed) AND (outside_temp > 15 AND < 25).
5. Start Small & Monitor: Implement one automation at a time. Use the Energy Dashboard and the Logbook (Developer Tools > Logbook) to see the immediate impact. A 5% reduction on a major load (HVAC) is a huge win.
6. Safety First: Never automate a device that could cause damage or danger without a physical override. This is especially true for heating elements, pumps, or anything with a high-fire risk. Automate when it runs, not if it can run unsafely.
7. Document Your Automations: Use the alias: field clearly. Add a description: field (in YAML) explaining the why and how. Future you will thank past you.

Conclusion: From Reactive to Proactive

Energy-saving automations in Home Assistant transform your smart home from a reactive tool to a proactive, optimizing system. The journey starts with awareness. This means the Energy Dashboard. It then moves to simple dead-man switches, called the zombie killer. Finally, it evolves into a context-aware ecosystem that understands occupancy, weather, and tariffs. Start with the examples provided, tailor them to your home and climate, and iterate. Every watt saved is a direct contribution to your wallet and the grid. The most powerful automation runs silently and efficiently. It requires no further thought. This is exactly what Home Assistant lets you build.