I just moved into a house that has a 2.5KW Enphase solar system connected to the main panel, which is under NEM 1 status, and I want to keep it that way. The main panel can handle 125A, and all my loads are connected to it.
I'm looking to increase my solar capacity and add batteries to minimize my utility bills, ideally down to zero. Additionally, I'd like to set things up so that I can use the batteries for backup power. I'm open to rewiring the whole main panel for this upgrade.
From my research, it seems possible to have a separate, parallel non-export system while retaining the NEM 1 grandfathering. However, I haven't found much information on how to proceed with this. Has anyone done something similar, or do you have tips on the best way to move forward? What kind of permits will I need from PG&E?
2 Answers
I suggest you go for a hybrid inverter and a battery setup. This way, you can limit your export while still expanding your array. With a moderate addition, you could see significant reductions in your bill and still maintain backup power.
You can actually add up to 1kW of capacity for export and still keep your NEM 1 status. I would recommend looking into adding two 500W panels using a microinverter to connect to your setup. Just make sure you have two breakers available in your panel for a 240V circuit.
One thing to note is that under NEM 1 rules, the cap is the lesser of 1kW or 10% of your existing system size, which for your case would only allow 250W.