I just wrote a post about making power savings using cheap home automation, but one story I heard there was next-level, and needed its own post. Wowee, I really hit the energy efficiency inspo jackpot!
I’m having fun tinkering around learning to use Home Assistant, an open source (free) software for automating things around your home. I went on to the Home Assistant user Facebook groups to ask for examples of how people are using it for energy efficiency and to save money on their bills. I received lots of very cool tips and suggestions, and summarised them in my other post. But Russell Heaton’s description of his off-grid setup was next-level. He’s kindly let me share it with you here.
Off-grid in hot country
Russell lives here in Western Australia, about 500km (300 miles) north of Perth. The climate is Mediterranean, with long hot dry summers and short wetter winters. The highest external temperate he’s recorded was 49.7C (121F), so you can see he really has some extreme heat to deal with. Lots of sun too, though, for plenty of solar power, on the other hand.
Western Australia is a very very big place, with some very very remote areas, and Russell is off-grid, meaning beyond the reach of the electrical power lines.
Oh no, wait, stop press, my bad! Russell just got back to me to say he’s NOT remote, and there IS a grid!
We actually live in a town which is on the Southwest Interconnected Grid. Our problem is that the grid supply has been terribly unreliable and, on one occasion after a cyclone (Seroja) we had no power for 16 days. I was already going to install solar, but the unreliability of the grid supply tipped the scales and we went off-grid.
Russell Heaton
If you’re in, say Europe, and you have a look at the map at that part of the country, you might be wondering if that doesn’t still count as remote, but no, here in Western Australia, that is very much ‘regional’ rather than ‘remote’ 😀
Making very smart use of his power
Here is what Russell told me about how he’s’ using the Home Assistant (HA) software to optimise his energy efficiency:
I use HA to control a timer on my hot water system, so that it doesn’t cook the water until the state of charge of my batteries has reached 95%. Then I make sure, using HA, that the hot water system doesn’t switch on more than once per day. It’s storage type and once per day is plenty and I definitely don’t want it operating at night, off the batteries.
HA also has the final say on when the electric vehicle (EV) charger is allowed to operate. The house batteries have to be 98% charged, or greater, before it will automatically kick in the EV charger. This can be overridden manually (as can the hot water system timer.)
HA also controls the fans and air conditioner in the room where the power equipment is located so that the equipment temperature never exceeds 27C and the batteries never exceed 25C, or get cooler than 20C.
I made some infra-red transmitters and use the Home Assistant Climate Integration to control all of my Daikin air conditioners and/or the ducted evaporative cooler.
This uses several humidity sensors to select the most appropriate cooling method, based on the humidity both inside and outside the house. Evaporative coolers lose effectiveness when the air drawn into them gets more humid. When that happens the system automatically switches over to the Daikin air conditioners.
Evaporative air coolers must vent their air to the outside world, so I also use HA to open some shutters and start some extraction fans in the power equipment room and all of the cool air passes through that room and expels into the ceiling cavity above. When it gets too humid the extraction fans turn off and the shutters close, then the air conditioners kick in.
Russell Heaton
And water efficiency too
And my original question was about energy efficiency, but that hardly scratches the surface of what you can get Home Assistant to do, so naturally Russell has not stopped there …
For water usage, I use HA extensively to monitor soil moisture and regulate how much water the gardens get.
The entire reticulation (irrigation) system is controlled by HA, not one of those commercial controllers that you buy from the big green hammer shed. I control 28 solenoids with HA.
HA also controls when our filtered water supply needs topping up and when to stop it topping up.
And it transfers water between the four storage tanks in the yard, as required.
The water filter is tricky because if the water is too warm it destroys the membrane in the reverse osmosis filter, so I use HA to monitor the temperature at the filter and it is only allowed to run if the temperature is below 34C.
Russell Heaton
Goals
Amazing. I’m in awe. Go Russell! Inspirational. If you want to ask him questions about his setup, here’s my original Facebook post in the Facebook group Home Assistant AU & NZ, and his comments.
I’m going to keep on pottering 🙂 Thankfully, in my more urban setting, with the grid to fall back on as needed.