Disclaimer: I haven’t done a lot of research yet. Still in the “how to handle this” stage.
My profile: Senior Full Stack Web App - with own infrastructure in the cloud, unraid locally. HASSOS in a vm.
Q: in September I’m getting solar panels. My parents lended me the money on the condition they can use up the extra energy I set the net. We live in Belgium and that is possible but to do so they have to take it at most 15 minutes after. For normal usage this is fine but I’m talking heat pump and machines and such.
Both houses have a home assistant setup. His is even more automated than mine. Both run on on a decent machine. Both have stable internet (UniFi) and he is paying for home assistant cloud. Atm I am not.
Now I do have a digital meter and just integrated that with my instance. First I made my own cable but then I stumbled upon “slimmelezer+” module and that thing is just fantastic!
Anyway now I have access to real time data. What would you do to get it to the other instance? I do not have a lot of time but I am experienced with webservices and have the servers. This would be read only off course! lol but I was wondering if any of you knew a project or has done this him/herself.
I’m thinking the easiest way would be for me to pay for cloud access and then create a user for them. They can then add my home to their apps. But it would be super duper sweet to fully integrate both houses!
I mean, don't misconstrue, I am exaggerating a bit and tend towards caution over utility in these matters - it's totally doable, of course :)
It's the overall intent that would worry me - as someone else said downthread, I'm not sure I see the necessity of having the two homes directly linked, and as we know, adding an unnecessary component to a system is necessarily increasing its threat surface. The involvement of a cloud service bothers me a bit - it'd be one thing to have three servers involved, all fully under your control, but what happens if your cloud provider has some kind of security disaster? How do you deal with an external adversary that then has access to both your and your parents' houses? Or worse, what happens when your parents decide to get experimental with HA and brick all your lights? (I kid - you do make it sound like your folks are switched on and technically sane, but in principle - shit can go wrong on their end).
Personally, I think I'd go very barebones and just host a single bit in a text file on a web server somewhere - your HA could flip it to 1 when there's power to buy, and your parents' HA can just poll that every 15 minutes and do whatever it needs to while the value stays at 1. No direct linkage, minimal threat surface, and any bad actor snooping around will only find out that some URL on some web server sometimes serves a '0' and sometimes serves a '1'.