My roommate and i both play bdo. Our pc's are running 24/7 for some fishing and worker silver. This has quite a bit of impact on the electricity bill ofcourse. I was wondering if its for example possible to run 2 instances on 1 low end pc instead of 2 rigged out game desktops.

Is there someone with a similar situation with a solution to save some money?

No, it's not possible!

Minimize to tray perhaps?

aside from the obvious, what I normally do to save more energy is;

optimal graphics, Upscale mode on Optimization, set resolution to 1280x960, minimize to tray.

then i change PC's power plan to Power saver & unplug my monitors.

a little tedious, but your pc will be producing barely any energy this way.

You can use a virtual machine for example vmware player with some modification in windows registry

or

you could try sandboxie

https://sandboxie-plus.com/

Running BDO in a vm to run multiple instances of the game on the same machine is not allowed!

Using a Virtual Machine to access BDO is allowed, as long as you are not using it to play on two different accounts at the same time, which does go against our Terms of Us.

If AFK fishing is considered as "playing" then maybe it is not allowed, but why should they care, it is by far neither cheating nor getting any advantage except some kind of sustainability and environmentalism.

Any action no matter if afk or active is considered as playing! So if they follow their own guidlines they will bann anyone who uses a VM to be online on 2 accounts.

And it doesn't matter how much or less advantage people have if they use it.

Here is my 2 cents, I fix that by getting a small mini cp with an AMD APU, and the system uses max 40W and 18w-20w while on system tray, that what i use for AFK, its playable but not pretty but for the purpose is more than enough.

this is the one i got:

Beelink 6 Cores 12 Threads AMD Ryzen5 5560U

On the bright side, you shouldn't be paying too much for heating. However, with software or bios settings you can limit the power/voltage on your computer - but, read a guide first.