Anyone here written home automation software to save on electric bills? I am currently using RPI CM4 based solution and my program written in 8th programming language to control heating of warm water for the cheapest hours on the Nord Pool market.
My current basic design inludes:
update task
manager task
scheduler task
control task
integrated webserver
So, it’s heavily multithreaded but tasks sleep most of the time. I am using integrated KV-database to save the price data and controller state. If there is a power failure, the controller continues where it left when power comes back again. I code and decode everything as bit level, so only a few bytes needs to be stored per day. Naturally there is also a backup program that activates when update task gives up trying to fetch the price data. Update task will try again the next day when that happens.
I don’t have time at this point in my life for home automation to that level but I do have a 1 KWH battery/inverter powering my office which charges at night when rates are lower (and could probably keep up with demand most days from solar panels if I had to). I am thinking of adding a 3KWH battery and inverter to the cellar to run the electrical side of the gas water heater and the condensate and circulating pumps attached thereto, plus the IP phone / internet router, ethernet switch to the office and one of the WiFi hot spots … if that were in place I could handle a full day’s power outage and still have my connectivity working (assuming that the upstream equipment from the ISP is itself properly backed up – if not, well, at least I have hot water, lol).
I now have a simple (and ugly) web page showing controller status and information about control events served by integrated web server (sorry about the Finnish language). When secure connections are needed, I will be using WebSockets and public key encryption for all the traffic between mobile application and server. There is also a support for MQTT style Publisher/Subscriber pattern coming.
Well my experiments with home automation are almost 5 years old. And I finally gave it up cause it does not bring any advantage. Basically you are adding a huge layer of complexity with half baked , after some years in many cases unsupported software. And they all failed the ultimate reality check: My wife had to use them with ease.
And when speaking of saving electricity bills, home automation is quite ineffective.
My best friends in saving electricity bills in their order of impact:
solar-powered inverter with or w/o batteries
low energy fridge and washing mashines (in general valid for all devices)
LED lamps and bulps everywhere
But the hardest thing is a change of behaviour. You have to cook, wash and load your smartphones and notebooks during daylight. Reduce your electrical devices, do not increase them by home automation. Try to use curtains and not electric roller blinds for instance. A manual coffe grinder than a full-automated Coffeemaker.
Last winter hourly spot prices were sometimes over 0,80 €/kWh here in Finland. So, without careful planning you could end up with electric bill over 2000 €/month. Sadly, the amount of solarpower produced energy at winter is very low.
That’s following the politics of decreasing nuclear power, gas and oil electricity plants and so on. Wind energy you will have only in windy times and solar energy only when the sun is shining. We may have no chance to get out of it when and if the politics not changing. And yes, they have no problem paying 2000 per month. Normal people have.
Also here in Germany the prices went up. In my company I had before the crisis around 1500,- per month, in best times I had to py 9 times more. That is the result of a green energy politic. While they are not in real calculating what is really needed but instead thing that they builded enough,. In my eyes there is no way around hydrogen. We need it. So we need 4 times more installed capabilities than needed electric power.
Simple, fast, no problem. But the politics decided: we have enough energy.
