Cheapest Energy Windows for Home Assistant (Marketplace integration)

Installs: 56 sharing analytics
GitHub stars: 23
Connection: Works locally
Upkeep: No update in 6 to 18 months
Version: v1.0.7, December 30, 2025
Category: Energy, Meters and monitoring
Kind: Marketplace integration
Needs: Needs the Marketplace (HACS on 2026.10 and older)
Domain: cheapest_energy_windows
Source: github.com/cheapest-energy-windows/cheapest_energy_windows
Issues: Report an issue

Independent directory, made by the developer of Vulpo. Not affiliated with Home Assistant or the Open Home Foundation.

Screenshots From the README of cheapest-energy-windows/cheapest_energy_windows.

About

Cheapest Energy Windows finds the cheapest charging and most expensive discharging periods from dynamic electricity prices. It reads prices from Nord Pool or ENTSO-E sensors and picks windows of 15 minutes or one hour, using percentile limits and minimum price spreads. Battery behavior is set through idle, charge, discharge, aggressive discharge and off modes, each of which can be linked to an existing automation or script. The integration creates and maintains its own battery control automation, so no YAML editing is needed. Further options include a price override that charges below a set price, separate settings for today and tomorrow, time overrides, quiet-hours notifications and protection based on state of charge. Setup runs through the UI, and the integration works locally.

Automatic summary of the README and code of cheapest-energy-windows/cheapest_energy_windows. Something wrong, or are you the maintainer and want your own text here? Get in touch

Supports

Works locally Talks to your devices on your own network. No vendor cloud in between.
From the Marketplace Installed through the Marketplace, formerly HACS.

Provides

Switches
Sensors

Setting it up

Install it from the Marketplace and restart Home Assistant, then add it under Settings, Devices and services.

Cheapest Energy Windows Setup

Setup TypeChoose between guided setup with configuration options or quick setup using defaults

Select Price Sensor

Price SensorThe sensor must have 'raw_today' attribute with hourly/15-minute price data

Configure Cost Parameters

VAT RateVAT rate as decimal (e.g., 0.21 for 21%)
Tax per kWh (EUR)Fixed tax amount per kWh in EUR
Additional Cost per kWh (EUR)Additional costs per kWh in EUR (grid fees, etc.)

Base Usage Tracking

Household Base Load (Watts)Average constant power consumption (lights, appliances, standby devices)
During ChargingHow base load is handled while battery charges
During IdleHow base load is handled when battery is idle
During DischargeHow base load affects discharge calculations
During Aggressive DischargeHow base load affects aggressive discharge calculations

Configure Battery Power

Charge Power (W)Battery charging power in Watts (800W is typical for single battery)
Discharge Power (W)Battery discharging power in Watts (used for calculating kWh)
Battery RTE (%)Round-trip efficiency 50-100% (85% typical, accounts for conversion losses)

Configure Pricing Windows

Window DurationMatch this to your energy contract (15-min or hourly pricing)
Charging Windows (how many cheapest time slots)How many cheapest time windows to use for charging (1-96)
Discharge Windows (how many most expensive slots)How many most expensive windows to use for discharging (0-96)
Cheap Percentile % (1-50, lower = stricter)Percentile threshold for identifying cheap prices (1-50%)
Expensive Percentile % (1-50, lower = stricter)Percentile threshold for identifying expensive prices (1-50%)
Min Spread Charge % (price difference needed)Minimum price spread % required to activate charging (0-200%)
Min Spread Discharge % (price difference needed)Minimum spread % required for normal discharge (0-200%)
Aggressive Spread % (for peak discharge)Spread % required for aggressive peak discharge (0-300%)
Min Price Difference (EUR/kWh, optional)Absolute minimum price difference in EUR/kWh to activate charging (0-0.5)
Enable Price OverrideAlways charge when price drops below threshold, ignoring spread/window requirements
Price Override Threshold (EUR/kWh)Price threshold in EUR/kWh - charge immediately when spot price is below this value (0-0.5)

Battery System Configuration (Optional)

Battery System NameFriendly name for your battery system (leave empty to skip)
State of Charge SensorSensor showing current battery charge % (0-100). Example: sensor.battery_soc
Available Energy SensorSensor showing available battery capacity in kWh. Example: sensor.battery_available_energy
Daily Charge SensorSensor tracking total energy charged today in kWh (must reset daily)
Daily Discharge SensorSensor tracking total energy discharged today in kWh (must reset daily)
Current Power SensorSensor showing current battery power in W (positive=charging, negative=discharging)

Battery Operations (Optional)

Idle Mode ActionSelect automation/script for idle mode. Example: Set battery to follow grid (Smart Matching)
Charge Mode ActionSelect automation/script for charge mode. Example: Enable battery charging from grid at max power
Discharge Mode ActionSelect automation/script for discharge mode. Example: Enable battery discharge to grid at normal power
Aggressive Discharge Mode ActionSelect automation/script for aggressive discharge. Example: Enable maximum discharge power during peak prices
Off Mode ActionSelect automation/script for off mode. Example: Set battery to manual mode when automation is disabled

After setup

Price Sensor
VAT Rate
Tax per kWh (EUR)
Additional Cost per kWh (EUR)

Texts from the code of cheapest-energy-windows/cheapest_energy_windows.

Entities

SelectsBase Usage: During Charging, Base Usage: During Idle, Base Usage: During Discharge, Base Usage: During Aggressive Discharge
SensorsCEW Today, CEW Tomorrow

Actions

Rotate Tomorrow SettingsApply tomorrow's settings to today (usually done automatically at midnight)

From the README

Optimize your energy consumption and battery storage by automatically identifying the cheapest charging windows and most expensive discharging periods based on dynamic electricity prices from Nord Pool or ENTSO-E.
🔋 Zero-Configuration Battery Control: Automatically creates and manages battery automation - just link your existing battery scripts/automations
🔗 Battery Operations Linking: Connect any automation, script, or scene to battery states directly from the dashboard
🤖 Auto-Managed Automation: The integration creates, updates, and maintains the battery control automation automatically (even survives restarts and upgrades)
📱 Smart Notifications: Configurable notifications for all state changes with quiet hours support
🛡️ SOC Safety Protection: Automatic battery protection based on State of Charge limits
💰 Price Override: Automatically charge when prices drop below threshold, regardless of calculated windows

From the README of cheapest-energy-windows/cheapest_energy_windows, MIT License. Shortened.