Net metering customers grew 100-fold from a median of 30 per utility in 2008 to 3,108 in 2024. This is the most dramatic growth trajectory in the EIA Form 861 dataset — no other program or metric changed by two orders of magnitude over the same period. The driver is rooftop solar: panel costs fell 90% between 2010 and 2024, making distributed generation economically accessible to ordinary residential customers.
California dominates the penetration rankings. SDG&E at 24.4%, PG&E at 17.7%, and Southern California Edison at 15.2% reflect both California's strong solar resource and its aggressive net metering policies, including NEM 2.0 which offered full retail rate compensation for exported electricity. Arizona utilities at 12-15% penetration show the Southwest's favorable solar economics even under more restrictive NEM policies.
Net metering penetration is the leading indicator of the utility death spiral dynamic — as more customers generate their own power, they buy less grid electricity, forcing utilities to raise rates to recover fixed costs, which incentivizes more customers to go solar. SDG&E's load trend data in T-22 showed -19% total load and -44% per-customer consumption since 2008 — the net metering penetration data shows exactly why.
| Utility | NM Customers | Installed Capacity (MW) | Penetration Rate | Growth 2008→2024 |
|---|
| Year | NM Customers | Penetration Rate |
|---|---|---|
| 2024 | — | — |
| 2023 | — | — |