5 Home Assistant Automations That Save Energy

Thu, 20 Aug 2026 00:00:00 +0000

My router, speakers, AV receiver, and printer used to draw a combined 76 watts while doing nothing. If they ran around the clock, that would cost almost €180 per year at my electricity rate. This is where automations help me: not through one spectacular trick, but by preventing small amounts of wasted energy every day.

Here are five solutions from my actual home. Four reliably reduce my energy costs. The fifth sounded sensible but provided no benefit with my heat pump, so I removed it again.

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1. Automatically switch off standby power hogs

My home currently draws around 55 watts of base load when idle. This includes devices that need to remain reachable for the smart home, such as Shelly modules, sensors, and my home server. I consciously accept that consumption.

Several other devices, however, used to stay on even when nobody needed them:

Device	Power	Annual cost if always on
FRITZ!Box router	16 W	almost €40
Five Sonos speakers	35 W	over €80
AV receiver	15 W	around €35
Printer	10 W	around €24

Together, these examples add up to 76 watts. My actual savings are lower than the theoretical €180 because I do not keep the devices off permanently. Home Assistant simply makes sure they are off whenever I do not need them.

When I leave the apartment, I long-press the hallway light switch. This deliberate “I’m leaving” signal switches off Sonos, the receiver, and the printer. The manual trigger is intentional: for this use case, I prefer an unambiguous button press over presence detection that occasionally gets it wrong.

I also switch off the FRITZ!Box at night. My smart home continues to run locally without internet access. I explain why local operation matters in Home Assistant A–Z: O for Offline.

There is a small downside: the Sonos speakers need about a minute after power-up, while the router takes roughly two minutes before everything is available again.

2. Run large loads on solar power

If you have solar panels, flexible high-power appliances should run whenever enough of your own electricity is available. In my home, this mainly applies to the washing machine and electric car.

My washing machine is connected to Home Assistant through Home Connect. In the morning, I load it, select a program, and enable remote start. Once around 2.5 kilowatts of surplus solar power are available, Home Assistant starts the machine automatically.

The car follows the same principle. My Heidelberg Energy Control wallbox is connected to the solar system through Home Assistant and evcc. The Cupra Tavascan charges primarily on surplus solar power unless a defined minimum state of charge takes priority. Of the roughly 3,500 kilowatt-hours the car uses each year, about 1,500 kilowatt-hours come from my own roof despite my relatively small solar array.

3. Get reminded to ventilate efficiently

Leaving a window open for too long wastes heating energy in winter. With a heat pump, that directly becomes additional electricity consumption. I therefore monitor the windows I regularly open using six Homematic contact sensors. The outdoor temperature comes from my heat pump sensor via Modbus.

My simple rule, deliberately tailored to my home, is:

Below 5 °C: send a reminder after 5 minutes
Between 5 and 15 °C: use the temperature as the number of minutes
Above 15 °C: do not send a reminder

If a window remains open beyond that limit, the Home Assistant app sends a push notification. This prevents forgotten windows without creating unnecessary alerts during mild weather. These values are not a universal ventilation formula; they are thresholds that work well for my building.

Bonus: Automate the electricity price too

Advertising: This section is part of a paid partnership with remind.me. The service is currently available in Germany.

Automations can reduce consumption or shift it to times when your own solar power is available. Another factor is the price per kilowatt-hour. During my most recent provider switch, I saved 5 cents per kilowatt-hour and received an additional €250 switching bonus.

The remind.me switching service checks once a year for the best suitable electricity, gas, or heat-pump tariff and prepares the switch. New-customer bonuses are included, and you have the right to veto every switch.

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4. Why I removed night setback

Turning down the heating at night sounds like an obvious way to save energy. Whether it works depends on the building, heat emitters, heat source, and control system.

In a poorly insulated older building with conventional radiators, night setback can indeed save energy. With my combination of a heat pump, underfloor heating, and a high-mass screed floor, however, the room temperature barely drops overnight. If the controller then catches up in the morning using a higher flow temperature, that less efficient operation can consume the small theoretical saving.

Night setback provided no measurable benefit in my setup, so I removed the automation. The better rule is not to apply it blindly, but to compare actual consumption over equivalent periods.

5. Shutters save energy in summer and winter

My shutters close automatically based on the position of the sun. This saves energy in two ways:

In summer, they keep solar heat outside, reducing the work required from an air conditioner.
In winter, closed shutters add another layer in front of the windows at night, reducing heat loss and the amount of electricity required by the heat pump.

I explain how to create sun-dependent shading with Home Assistant blueprints in Home Assistant A–Z: J for Shutters.

Conclusion

None of these automations is a revolution on its own. Together, however, they prevent unnecessary standby consumption, make better use of solar power, and reduce wasted heating or cooling energy. Once configured, most of them run almost entirely by themselves.

Night setback is the important counterexample: an automation does not automatically save energy just because it is commonly presented as an energy-saving tip. What matters is what it actually does in your home.

Which smart home automation saves the most energy for you – and which supposed energy-saving trick did you switch off again?

Smart Electricity Tariff for Your Smart Home: Worth It?

Wed, 25 Dec 2024 00:00:00 +0000

€180 less per year for charging the EV – that’s not a promise from a provider, but a concrete real-world calculation: anyone who charges their car at home and has the right tariff simply pays less, because electricity is significantly cheaper at night or when there’s plenty of wind and solar energy on the grid.

That’s exactly what dynamic electricity tariffs make possible. Whether it makes sense for you depends on one key factor.

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What Is a Dynamic Electricity Tariff?

Dynamic electricity tariffs are based on fluctuating prices that follow supply and demand on the electricity market. Unlike traditional fixed-price tariffs or time-of-use tariffs with fixed peak and off-peak windows, prices under a dynamic tariff can change every hour or even every quarter-hour.

For such a tariff to work, you need either a smart meter or an additional device that records your electricity consumption in real time. Only then can your provider match your actual usage data to the dynamic prices.

Pros and Cons of Different Electricity Tariffs

Tariff type	Price changes	Price guarantee	Savings potential
Fixed tariff	None	Fixed	Low
Time-of-use tariff	Fixed time windows	Partial	Medium
Dynamic tariff	Hourly / every 15 minutes	None	High

A dynamic tariff is most worthwhile if you own high-consumption devices such as washing machines, tumble dryers, dishwashers, or electric vehicles that you can run flexibly.

Calculation Examples: How Much Can You Save?

1. Washing Machine and Tumble Dryer

Assumptions:
- 2 laundry days per week.
- Energy use: 1 kWh (washing machine) + 2 kWh (dryer).
- Fixed tariff: 30 cents/kWh.
- Dynamic tariff: Average 25 cents/kWh.
Calculation:
- Saving per laundry day: 3 kWh × 5 cents = 15 cents.
- Saving per year: 15 cents × 104 laundry days = €15.60.

2. Electric Vehicle

Assumptions:
- Annual mileage: 20,000 km.
- Energy use: 20 kWh/100 km.
- 90 % of charging done at home (3,600 kWh).
- Saving: 5 cents/kWh.
Calculation:
- 3,600 kWh × 5 cents = €180 savings per year.

Smart Home Automation

With a smart home you can optimise your consumption without constantly having to check for cheap electricity windows. For example, you can set your EV to automatically charge during the cheapest hours while still being ready to drive in the morning.

My Recommendation: Tibber

One provider offering dynamic electricity tariffs is Tibber. With a monthly base fee of only €3.99 and transparent pricing, Tibber is an excellent choice. Particularly handy: the Tibber app shows you hourly electricity prices in advance and makes it easy to reach customer support.

If you don’t have a smart meter yet, you can use the Tibber Pulse device to track your consumption hourly.

Just Want to Keep an Eye on Your Consumption?

Don’t want a dynamic tariff (yet), just want to see where your electricity goes? That’s much simpler and cheaper: the OBI Energy Tracker* attaches to your electricity meter and shows your consumption in the heyOBI app – no tariff switch and no expensive smart-meter retrofit.

Conclusion

A dynamic electricity tariff can help you save on energy costs, especially if you own high-consumption devices like an EV. With the right automation, using it becomes simple and efficient.

Note: Links marked with affiliate link are affiliate links. As a partner of Amazon and OBI (via the Awin network) I earn from qualifying purchases. This means I receive a small commission if you purchase through these links — at no extra cost to you. The revenue helps me run this blog and YouTube channel and keep creating content. Thank you for your support!
― Joachim

Energy Saving on Smart Home? Sure — But Secure!

5 Home Assistant Automations That Save Energy

1. Automatically switch off standby power hogs

2. Run large loads on solar power

3. Get reminded to ventilate efficiently

Bonus: Automate the electricity price too

4. Why I removed night setback

5. Shutters save energy in summer and winter

Conclusion

Smart Electricity Tariff for Your Smart Home: Worth It?

What Is a Dynamic Electricity Tariff?

Pros and Cons of Different Electricity Tariffs

Calculation Examples: How Much Can You Save?

1. Washing Machine and Tumble Dryer

2. Electric Vehicle

Smart Home Automation

My Recommendation: Tibber

Just Want to Keep an Eye on Your Consumption?

Conclusion