Solar comparison
California NEM 2.0 vs NEM 3.0: How Net Metering Changes Affect Solar Payback
Compare California NEM 2.0 and NEM 3.0 solar billing rules: export credit values, battery impact, payback period changes, and how to maximize savings under NEM 3.0.
Quick answer
What this comparison means
NEM 3.0 (effective April 2023) reduced solar export credit value by ~75% compared to NEM 2.0. Under NEM 2.0, exported solar was credited at near-retail rates (~$0.25–0.35/kWh). Under NEM 3.0, exports are credited at avoided-cost rates (~$0.04–0.08/kWh). This makes battery storage central to solar economics: self-consuming your solar is now worth 3–5x more than exporting. Solar-only payback extended from 5–7 years (NEM 2.0) to 8–12 years (NEM 3.0). Solar + battery payback under NEM 3.0 is 8–12 years — similar to solar-only under NEM 2.0.
Comparison table
| Factor | Option A | Option B | Why it matters |
|---|---|---|---|
| Export credit value | Near-retail rate (~$0.25–0.35/kWh) | Avoided-cost rate (~$0.04–0.08/kWh) | NEM 3.0 export credit is ~75% lower. Self-consumption is now the dominant strategy. |
| Solar-only payback | 5–7 years | 8–12 years | NEM 3.0 roughly doubles solar-only payback. Battery becomes much more important. |
| Solar + battery payback | 8–12 years (battery less valuable under NEM 2.0) | 8–12 years (battery is central under NEM 3.0) | Under NEM 3.0, solar + battery payback ≈ solar-only payback under NEM 2.0. |
| Battery strategy | Nice-to-have for backup and small TOU savings | Essential — store daytime solar for evening use instead of exporting at low credit | Under NEM 3.0, every kWh you store and use yourself saves $0.30+. Every kWh you export earns $0.05. |
| System design shift | Maximize panel count for maximum export | Right-size panels to daytime load + battery capacity; avoid overproduction | NEM 3.0 rewards matching production to consumption. Oversizing wastes value. |
| Grandfathering | NEM 2.0 customers grandfathered for 20 years from PTO date | All new applications after April 14, 2023 | If you have NEM 2.0, you keep it. Adding battery doesn't trigger NEM 3.0 transition (under 10% expansion rule). |
| Best next check | Maximize production before NEM 2.0 transition; add battery later if desired | Model evening load profile and battery dispatch; get multiple battery-inclusive quotes | Every CA homeowner should run a self-consumption model before sizing their system. |
Data Sources
This comparison uses state electricity-rate ranges, local incentive context, net-metering rules, and solar production assumptions informed by NREL PVWatts-style modeling. Final quotes, utility tariffs, and interconnection rules can materially change the economics.
Assumptions
Payback and ROI are directional estimates, not financial advice. They assume typical residential roof conditions, stable household usage, currently available incentives, and separate treatment of battery backup value, financing costs, and installer-specific add-ons.