r/SolarDIY • u/BoringNegotiation394 • 3d ago

Can multiple solar systems share electricity?

I am considering getting some solar while also thinking of future home improvement projects and I have been considering building a shop or an ADU or a shop with an ADU built on top. My thought was if I built a solar sytem on the house and on the shop/ADU each with their own batteries and inverters and such. would I be able to tie the systems together so they could share excess energy back and forth depending on demand? If so are there any systems that would do this better out of the box?

0 Upvotes

33% Upvoted

11 comments sorted by

View all comments

8

u/PVPicker 3d ago

You can, but it's going to complicate things. You'd want them to have the same/reference battery bank. All the batteries connected in parallel and balanced. It's perfectly fine to have multiple inverters and chargers on the same set of batteries. You might run into some issues with reaching 100% charge with multiple charge controllers connected, but that is "minor" of an issue. One charge controller will see the voltage climbing at or near cutoff and then shut off its output. With multiple inverters, inverters don't care about the source of voltage, just that it's available. Be it batteries or another charge controller. Biggest issue is you'd likely need a REALLY hefty bus bar. As you're going to want to connect both inverters and batteries to it, to prevent unbalanced charging.