agileElectrification ProjectCPUC IOU fleet · 2015–2025 · data vintage 2026-05-31
A New Deal for California DERs
Two million rooftops were built to sell power to the grid. The economics have flipped to self-consumption, and 1.76 million of those homes have no battery yet. Watch the build-out, switch on the layers, and hover any county or the ⓘ on a layer for the detail.
Installed solarbase · 2014–2025
Base layer · installed solar
California built the largest residential solar fleet in the country, one roof at a time.
Net metering, falling panel prices and 18,938 contractors turned rooftop solar into infrastructure. Across IOU territory the base grew 7.5× in eleven years. The county fill follows the year shown; hover any county for its numbers.
Installed base & battery attachyear-end · new-system attach %
Attach stayed near zero until 2018 and jumped to 52% (2024) and 67% (2025) after NEM 3.0. Everything installed before that is a retrofit candidate.
Installed residential rooftop solar by countycumulative systems · PG&E, SCE and SDG&E territory
283,324
systems
1.4 GW
DC capacity
0.2%
new w/ battery
2014
Loading California county geometry…
Solar systems (fill)0311kno IOU data
Homes with a batteryring area ∝ homes already storing, end-2025
Battery-ready homesdisc area ∝ solar homes without a battery (same scale as ring)
20142025
Reading the map
IOU territory only. CPUC data covers PG&E, SCE and SDG&E. Municipal utilities (SMUD in Sacramento, LADWP in Los Angeles city, Imperial Irrigation District, Modesto and Turlock ID) do not report here, so Sacramento, Imperial and Stanislaus read far below their real fleets. Alpine, Del Norte, Modoc and Siskiyou have no IOU footprint in the extract.
Year-by-year county fills are interpolated from each county's 2014 base and 2015–2025 additions along the statewide growth curve; county totals and additions are exact. Layer symbols use year-end 2025 values.
One approved interconnection application = one system; counts run roughly 10–15% above unique rooftops. Battery figures use the SDG&E-corrected county columns.
GW in the potential layer is illustrative: battery-ready homes × the kW you set.
Sources
CPUC California Distributed Generation Statistics, Rule 21 interconnection applications, dataset 2026-05-31 (residential, solar, approved through 2025-12-31).
Agile Electrification Project, Solar & Electrification: Flexible Pathways for Energy Independent Homes in California, Feb 2025.
County boundaries: amCharts geodata (California counties), loaded at runtime.