Can I Add a Battery to My NEM 2.0 Solar System Without Losing My Status?
If you installed solar before April 2023, you probably have NEM 2.0 — one of California’s most favorable net metering programs. Understandably, homeowners often worry that adding a battery today might force them into NEM 3.0, which offers much lower export credit rates.
The good news? You can add a battery to your existing NEM 2.0 solar system and keep your NEM 2.0 status — if you do it correctly.
NEM 2.0 + Battery: What the CPUC Says
The California Public Utilities Commission (CPUC) explicitly allows homeowners to add paired energy storage to an existing solar system without triggering a tariff change.
Paired Storage means your battery charges only from your solar system, not from the grid.
As long as no new solar generation is added (or it’s under 10% of your original system size / 1 kW, whichever is greater), your NEM 2.0 agreement stays intact.
What About Exporting Battery Energy?
Many homeowners ask:
“If my solar panels and my battery export power to the grid at the same time, am I exceeding my original system size?”
Here’s the key distinction:
System size is defined by your solar inverter’s AC rating, not your momentary export.
A battery isn’t considered new generation — it’s just time-shifting solar energy.
You can export solar-charged battery energy back to the grid and still get full NEM 2.0 credit.
This means that even if your solar system is exporting 6 kW while your battery discharges 5 kW at the same time (total 11 kW), you are still within your NEM 2.0 rights.
How PG&E’s Portal Handles It
When you submit your interconnection application to PG&E, you’ll see a question:
“Do you plan to limit export?”
In most cases, the answer is No for a NEM 2.0 paired-storage retrofit.
No = Open Export: Your battery and solar can export their full output when available, earning you credits.
Yes = Export Cap: This is used only if PG&E or your AHJ imposes a service size or Rule 21 export limit that you must enforce.
Our Process at Ally Electric & Solar
When we retrofit batteries like the Enphase IQ 10C onto existing NEM 2.0 systems, we:
Configure the battery to charge only from solar (paired storage compliance).
Confirm that the interconnection is filed as a “Standard NEM Paired Storage” project, not as a new solar system.
Leave export open unless your utility specifically requires a limit.
Provide documentation citing CPUC Decision D.16-01-044 to ensure PG&E keeps you on NEM 2.0.
💡 Why Add a Battery Now?
With time-of-use rates and evening peak prices climbing, batteries let you:
Store your own solar power for nighttime use.
Ride through power outages with backup capability.
Maximize your NEM 2.0 benefits before the 20-year term expires.
Bottom Line
Adding a battery to your NEM 2.0 system is one of the best investments you can make right now — and it won’t bump you into NEM 3.0 if it’s done properly.
Want to explore whether a battery is right for your home? Contact Ally Electric & Solar today at 510-559-7700 — we’ll check your existing system, design a solution with the right size battery, and handle the entire PG&E interconnection process for you.