I’ve got some grand ambitions for home automation, but at the moment I’m taking baby steps. For inspo I asked asked some Home Assistant fans how they’re using it to save on their power bills, and here are some of their fantastic answers.
(I’ll come back to what Home Assistant actually is in a moment, and its pros and cons, but the short answer is that it’s free software that you can use to join up all kinds of devices around your home.)
Real life examples
Using Home Assistant to turn off things that don’t need to be on:
- Turning off the heated towel rail overnight if no-one showers in the evening.
- Turning off the corridor lights after ten minutes.
- Turning off inessential power sockets (outlets) during sleep/work/vacation hours.
- Using the internal humidity to control bathroom extractor fans.
- Lighting coming on automatically at dusk, but only if the presence detectors see that someone is at home.
- Turning several devices off if the power of one drops below a certain wattage – for example if the TV is turned off, turn off the soundbar, streaming box, etc.
- Turning power off at 1am.
To make intelligent responses to changing circumstances:
- Turning off the aircon if an outside door is left open for more than ten minutes.
- Opening or closing electric window shutters depending on the internal and external temperatures.
- Monitoring electrical consumption, becoming aware of what you’re using, leading to using energy better.
- Smart charging for laptops.
- Controlling ducted gas heating using temperatures, humidity, who’s at home, bed sensors, whether the blinds are up or down.
To give you a heads up if action is needed:
- Sending you an alert if the fridge door gets left open.
- Sending a notification if an outside door is left open for more than ten minutes.
- In a hot climate with cool nights, sending a notification to your phone when the outside temperature drops below the inside temperature and it’s time to open the windows to start flushing out heat.
To optimise self consumption from your solar panels:
- Controlling the electric vehicle charger minute-by-minute to use up the surplus power from the solar panels.
- Running the aircon automatically when you have surplus solar panel production in the middle of the day.
- Switching on the pool pump when there’s enough solar. With some additional logic set up to make sure the pool does still get enough filtering.
- Switching on the hot water heat pump when the solar panels is producing enough surplus power. Making sure it only gets switched on once per day.
- Getting an alert if you exceed your solar production – for example if you turn on the dishwasher while the washing machine is already running.
To stop your kids running riot with your electricity bill:
- Turning off the kids’ bedroom lights after ten minutes if there’s no movement in the room.
- Using individual temperature zones, set points and thresholds in each room, to stop the kids setting their room to igloo during summer, or the Sahara during the winter.
To make best use of your electricity tarriff:
- Scheduling things to turn on during the cheaper hours of your electricity tariff.
- Scheduling your hot water boiler on a hour-by-hour basis based on electricity price and predicted usage.
And for those on floating-rate electricity tariffs:
- Turning off all high-use appliances when the electricity cost goes about $1.
- Turning the heating and hot water tank to turbo mode when the electricity pricing goes negative (yowsers!)
- Turning off the gas and turning on the electric immersion element when the electricity price dips below the gas price.
And there were more! Here are links to the posts where I asked this question in the Facebook groups Home Assistant, and Home Assistant AU & NZ. The most impressive example came from an off-grid home 500km (310 miles) north of Perth, which so amazing I’ve written a whole separate blog post about it here!
My own baby steps
My own best example so far, super basic but still super useful, is an alert I get on my phone on summer evenings to tell me when the outside temperature has dropped below the inside temperature, and it’s time to open the windows to flush the heat.
Here in Perth, Western Australia, this is a traditional, highly effective, and free way of managing excess heat, by taking advantage of the large diurnal swing in this Mediterranean climate, meaning the big drop in temperature at night time.
It was really interesting to see as summer worked its way through that this point varied between 3pm and 11pm, so having the alert was very useful. My evenings were more comfortable, despite turning the aircon off earlier. Or to know that the temperature switch was going to come after my bedtime, so it would be one of the handful of nights where I’d need to keep the windows close and run the aircon all night.
I’ve written a blog post here about my own little setup, what it’s doing, and what it cost, which so far is a modest AU$355 (US$239), giving me a platform to start doing all different interesting things around the house.
What is Home Assistant?
Home Assistant is certainly not the only way to automate your home, there are all kinds of options out there. And it’s not only useful for energy efficiency, I originally came across it when I was researching CCTV solutions. Its applications are as broad as you can imagine.
You can get it to remind you that it’s bin day, and which colour bins need taking out. Or you can make it stop your kids turning on the TVs in their rooms before 6am. The funniest one I’ve read was someone who says that he has fun showing visitors to his home that he can stand in his bedroom and say “it’s time”, and the lights dim and the sound system plays Barry White.
A more prosaic example, that I’d like to implement when I get round to it, is someone who gets an alert to their phone when the price of petrol (gasoline) at one of his local servos (gas stations) drops below a certain dollar figure. This illustrates something really cool about Home Assistant, which is that it can interact with data from outside your home as well as inside. Such as a website that has a feed for your local fuel prices, or for your local weather forecast.
I’ve heard Home Assistant likened to the conductor of an orchestra. It’s not a range of equipment, it’s a piece of software. You can use it to co-ordinate practically any device in your home that has any kind of connectivity, whether that device uses WiFi, Bluetooth, infra red remote control, smart speakers, smart plugs, or a long list of communications technologies with names like Zigbee, Z-Wave and Matter.
It’s free
Home Assistant is free. It’s open source software, meaning that it is developed and maintained by its community of users.
It’s not owned by a commercial company. There is no purchase price or subscription fee. This was one of the things that appealed to me, having installed various hard-wired systems in my previous renos – burglar alarms or smart heating or CCTV – that ultimately never quite worked well enough, and were not flexible or easy to adapt over time.
The flipside is that Home Assistant does not come with guarantees or a helpdesk. Personally I most certainly would NOT use it for any security-critical task like locking the front door, which I see some people do, using smart locks.
Home Assistant is a DIY project, for people who like to learn and like to tinker. You need to run it on some kind of hardware, and you could buy a Home Assistant Green or a Raspberry Pi for that, or, if you have an old laptop lying about, you can use that.
So you could get started for, literally, free. With nothing hard-wired into your home. But, you will probably also want to start buying a few bits and pieces to expand what you can do with it. And right down the other end of the scale, some people sound like they must be spending a lot of money, hard-wiring all kinds of controllers and sensors into their homes. One commenter said that they’d saved more on their electricity bills than they’d spent on tech, and I think that’s probably very achievable.
Advantages
- Potential to make your daily life easier, cheaper and more fun, through clever automations.
- Free.
- Can connect a huge range of devices together.
- Can integrate external sources of data such as the weather forecast.
- Not tied to one manufacturer or proprietary system.
- Extremely flexible, adaptable, and future-proof.
- You can have it communicate with you, and send you alerts however suits you – by phone notification, email, smart speaker announcement, turning a smart light bulb on, through a touch-screen wall panel.
- Can be set up as an entirely local system (not interacting with the internet or the cloud at all).
- Plenty of your system can be portable, and easily moved with you when you move house. I moved, plugged all my devices back in, and the whole thing carried on working perfectly.
- A lively online community of You Tube videos, blogs, Facebook groups, etc, to help you figure out how to get things done.
- The sky’s the limit in thinking up clever ways to integrate all of these things.
Disadvantages
- A DIY option, which takes a lot of time and patience to learn and configure.
- No IT helpdesk, no guarantees, no-one to call when you’re stuck or if something goes wrong.
- This hasn’t happened to me yet but I see a lot of people complaining that their installation crashes each time they install a Home Assistant update (which are issued very frequently).
- Some of the solutions I see online are definitely beyond my skills, involving disassembling devices and installing new software on them.
- Even for tasks that I think I probably could tackle, sometimes the advice is written in ways that flies straight over my head, a portion of the Home Assistant community look to be IT professionals, speaking IT professional language.
- I certainly wouldn’t rely on it for anything mission-critical, like locking the front door.
- The “WAF” gets mentioned a lot in this largely male community – the Wife Approval Factor – just because you CAN automate something, it doesn’t mean you actually should, and that you and your family are going to prefer the outcome to just simple old fashioned solutions like a manual light switch.
- It’s definitely possible to get carried away and spend more money automating things than you’ll ever save, just because you can. And it’s fun. And it’s addictive.
Something to add?
Head over to my blog’s Facebook page and add a comment to let me know anything else cool that you’re doing with Home Assistant for energy efficiency, and I’ll add it to the list 🙂
And if you’re building from scratch, I’ve also written about how to get free heating and cooling from good passive solar design. And the Rolls-Royce solution of a certified Passive House.
Image by Gerd Altmann from Pixabay