CAN I ADD MORE SOLAR

WITHOUT LOOSING

NEM 1.0 or 2.0?

If your solar system is grandfathered under NEM 1.0 or NEM 2.0 in California, you can typically add capacity without losing preference—so long as you follow the CPUC’s rules.

Key Rule: System Expansion Limit

  • You may increase system size by up to 10% of the original rated capacity or 1 kW, whichever is greater, without being reclassified under NEM 3.0.
    This is based on California Public Utilities Commission Decision D.14‑03‑041, Ordering Paragraph 3 and successor resolutions. See page 27 and 39
    (docs.cpuc.ca.gov)
  • If you exceed that threshold, your system may be considered a new interconnection and could be placed under NEM 3.0.
    (solarrights.org, exro.com)
  • Adding battery storage or upgrading within the same inverter does not affect your grandfathering.
    (enphase.com, greenlancer.com)

Grandfathering Duration

California law guarantees that systems interconnected before April 14, 2023 remain on their original NEM tariff (NEM 1.0 or 2.0) for 20 years from the PTO date. Grandfathering is not retroactive.

PUC Reference

California Public Utilities Commission (CPUC) Decision D.14‑03‑041 establishes that a modification exceeding 10% or 1 kW requires reclassification under a successor tariff.
See PUC § 2827 and related CPUC resolutions for system-size limits and grandfathering rules.
(docs.cpuc.ca.gov, energycenter.org)

Summary

QuestionAnswer
Can I safely add panels?Yes—up to 10% or 1 kW without affecting your NEM status.
Will battery installation affect my tariff?No—adding battery storage to the same system is allowed.
How long do I remain grandfathered?20 years from your PTO date under NEM 1.0 or 2.0.
Where to verify?Review CPUC Decision D.14‑03‑041, PUC § 2827, or consult your utility’s interconnection guide.

🔗 Useful Resources

Need help reviewing your interconnection application or planning an upgrade? Contact us for guidance tailored to your system.