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Energy management in the Home Assistant

TL; DR: We’re adding energy management and it’s great. Creates two products for reading electricity meters: SlimmeLezer for P1 ports & Home Assistant Glow for activity LEDs. Most of the existing energy integrations have been updated for compatibility.

The world is in a climate crisis. Global warming is a reality and the weather is becoming unpredictable. Our way of life needs to change on all levels. I worry that the world will try to solve the climate crisis too late and after irreversible damage has already occurred.

With Home Assistant, we want to do our part to help tackle the climate crisis and help you do the same. Part of fighting the climate crisis is making sure our homes are energy efficient and use low carbon energy sources.

Starting today, Home Assistant offers official support for energy management at home. Our energy management helps users monitor energy consumption, switch to sustainable energy and save money.

Show how home automation and energy management use the same data.
Home automation and energy management are based on knowing what devices are doing

Energy management and home assistant in context

Bill Gates was recently interviewed by Marques Brownlee (MKBHD) and spoke about how smart homes are needed for smart cities. And how it all starts with energy management in the house. The interview lasts 3 minutes and is worth watching:

When it comes to energy management, Home Assistant won’t have all the answers, at least not right away. But we have two important things for us that make us the perfect platform for your energy management:

The first is that we are completely open. That means anyone with Home Assistant can use the source or the data collected and build anything with it. We are already seeing this: The European Association of Citizens’ Energy Cooperatives is using Home Assistant to develop energy management software tailored to communities. We are part of a rich ecosystem with many different approaches, all of which are related to Home Assistant.

The second thing is that we have a passionate and global community that wants to make their home the best it can be. A community that revolves around creating and sharing their own hardware and software to achieve their goals. Through experimentation and iteration, we will be able to improve energy management over time to meet our needs – there are no investors to satisfy.

When it comes to your home, Home Assistant is the best platform to manage it and find out what works and what doesn’t.

Energy dashboard

Today’s version of Home Assistant Core 2021.8 includes a new energy dashboard (demo). The goal is to give users an insight into their energy consumption. The dashboard is designed to see at a glance how you are doing today with the option to also break down by the hour to see what happened when. It also includes indicators to help you identify your grid dependency and whether adding energy storage would improve your situation.

(top) Different ways of looking at your consumption will help you to better understand your energy consumption
(below) The energy consumption graph shows how much energy you have drawn from the grid per hour, how much energy you have produced and how much of it was fed back into the grid.

Users can see at a glance which energy sources have been used in their home. This knowledge includes the CO2 intensity of the electricity consumed from the grid, which is available thanks to electricMap.

When users have solar panels, they can set up the Forecast.Solar integration which allows users to see at a glance what today’s production will be like. This allows users to plan when to charge their electric car or heat extra water.

Energy management is complicated, so we made sure our energy settings are as simple as possible. They are accompanied by documentation to further explain the various concepts.

Users can configure their consumption and production and Home Assistant does the rest. Home Assistant can get energy data from any supported hardware, such as B. intelligent energy meters, inverters, current transformer terminals, heart rate monitors and intelligent plugs.

The configuration is divided into different sections.


Home Assistant is provider-independent and there is no provider connection. You can use any hardware you want. We have already upgraded many of the existing integrations for energy monitoring to work immediately with energy management.

In addition to supporting existing integrations, we have also created two open source hardware projects that will help you transfer your energy data to Home Assistant.

Smart reader

Most energy meters in the Netherlands, Belgium and Luxembourg have a P1 port on their energy meter. This port provides real-time usage statistics.

Together with Marcel Zuidwijk we designed and developed SlimmeLezer. This ESPHome-based product makes all P1 data immediately available in Home Assistant. P1 ports that use DSMR v5 protocol can also provide direct power to this device, eliminating the need for an external charger. The SlimmeLezer firmware is completely open source.

Buy a SlimmeLezer

SlimmeLezer on GitHub

Photo by SlimmeLezer on a smart electricity meter

Home Assistant Glow

Most energy meters flash a small light when a certain amount of energy has been used. Home Assistant Glow monitors this light and brings it to Home Assistant as a consumption sensor.

Home Assistant Glow is powered by ESPHome. Both the firmware and the housing are completely open source and can be created relatively easily yourself using the instructions provided.

The Home Assistant Glow was designed and developed by Klaas Schoute as part of his internship at Nabu Casa.

Home Assistant Glow on GitHub

Photo of Home Assistant Glow attached to an electric meter

That’s just the beginning

Today we released the very first version of energy management in Home Assistant 2021.8. We have a lot of ideas that we will add in the next few releases.

If you’re interested in helping out, don’t hesitate to drop by the new # devs_energy channel on our Discord server.

New opportunities for advanced users

Every home is different and so are the needs of the individual users. The energy management function in Home Assistant is created with existing Home Assistant modules: Lovelace & data storage. This means that our advanced users can create their own dashboards and use whatever elements they like from the energy dashboard.

In addition, advanced users have access to the new long-term statistics that have been added to Home Assistant. With this data, you can easily monitor most sensor data, not just energy data, over long periods of time.

Thank you congregation

Our home energy management has been in development for over six months and many people and companies around the world have contributed to this success.

We’ve improved the way Home Assistant stores data, renders charts, and improved many other parts. We have also expanded the sensor model in ESPHome and added new features to create devices that are ready to use out of the box with energy management. It’s been a lot of work from a lot of people and I’m very proud of what we have achieved.

It shows that open source works: when you bring together a group of people who are passionate about something, great things can be created.

My special thanks go to Klaas Schoute, who started the initial research as part of his internship at Nabu Casa. He researched available solutions, created his own solutions (Home Assistant Glow), conducted in-depth interviews with 20 Home Assistant users, created the first iterations of the dashboard and integrated new data sources in Home Assistant (forecast.solar). Thanks Klaas!

One of Klaas's sketches

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