EV solar education · Updated October 2026

Can You Add Solar Panels for an EV Without Losing NEM 2.0?

For an Orange County homeowner with grandfathered NEM billing, a solar expansion can affect much more than the number of panels on the roof. Confirm the utility and approved original generating capacity before purchasing equipment.

Understand the SCE expansion threshold

SCE states that existing NEM 1.0 and 2.0 customers can generally remain under their original program if their aggregate system capacity increases by no more than the greater of 1 kW or 10% of the original system size. A revised interconnection application is still required.

SCE instructs qualifying customers who want to retain NEM to choose the “NEM 1.0/2.0 Expansion” application type. Using the wrong pathway can result in migration to the Solar Billing Plan. An increase beyond the allowed threshold generally requires a new Solar Billing Plan application.

Calculate carefully before choosing panels

For example, the larger of 1 kW or 10% of an originally approved 6 kW system is 1 kW. For an original 15 kW system, it is 1.5 kW. These are illustrations of the stated threshold, not approval for a particular equipment design.

Approved capacity definitions, inverter or export controls, storage, historic system modifications and other technical conditions require an individual review. Do not assume adding one panel is automatically exempt from utility paperwork.

Alternatives if your EV needs more electricity

First assess lower-cost charging hours, daytime charging opportunities, current solar underperformance and household load management. You may be able to improve the bill without increasing solar capacity.

If a larger expansion is justified, compare the savings under your current grandfathered tariff against the financial effects of moving to a different billing plan. A battery may address some timing issues but also requires utility and technical review.

What to do next

Before authorizing an expansion, collect your original interconnection approval, system capacity, current utility bill and EV charging history. Read the current SCE source: https://www.sce.com/customer-service-center/help-center/solar/solar-billing-plan/solar-billing-plan-faqs

Is your current solar system ready for your EV?

Get a utility-aware review of your EV usage and your existing solar system. Solar Topper will explain options before recommending more panels.

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Educational estimates are illustrations, not guaranteed savings. Verify current utility rules and site-specific design before modifying solar equipment.