Solar interconnection permits in California
Last updated May 22, 2026
A plain-English starting point for electrical contractors. This is general California guidance — fees, forms, and timelines are set by each city.
Short answer
In California, installing a grid-tied solar PV system needs an electrical permit (often called a PV or solar-interconnection permit), pulled by a licensed C-10 or C-46 contractor. The work follows the California Electrical Code (Title 24, Part 3, Article 690) and California's expedited residential solar permitting (most cities use SolarAPP+). Battery-storage interconnection (Article 706) adds further scope.
The general picture
A solar PV interconnection ties the new array into the building's electrical system at the main panel, a backfed breaker, or a load-side/line-side tap. The permit covers module count and wattage, string and inverter configuration, the AC and DC disconnects, the interconnection point, grounding, rapid shutdown (NEC 690.12), and labeling. California requires expedited residential solar permitting — most cities use SolarAPP+ for instant or same-day issuance on code-compliant designs. The utility interconnection application (PG&E, SCE, LADWP, SDG&E) runs in parallel with the city permit and is the contractor's responsibility.
Typically needs a permit
The scope above — solar interconnection — itself triggers a permit in nearly every California jurisdiction. Specific variations and edge cases are confirmed with the issuing department.
Usually doesn't (general norm)
- Cleaning or replacing damaged modules with identical units on an already-permitted system (verify locally)
- Resetting inverters or rapid-shutdown devices
- Replacing monitoring or communications equipment that doesn't affect the electrical system
Documents & plans generally required
- Electrical permit application — many California cities use SolarAPP+
- Contractor license and city business registration
- Site/plot plan showing the array, conduit run, and interconnection point
- Single-line diagram with module / inverter / disconnect / breaker / OCPD ratings
- Module and inverter cut sheets (listed equipment)
- Structural attachment detail for roof-mounted systems (often deferred-submittal to engineer)
- Load calc + 120% rule check at the interconnection (NEC 705.12) — or supply-side tap detail
- Rapid-shutdown initiation and labeling per NEC 690.12 and the local code cycle
- Utility interconnection application (handled in parallel with the city permit)
Common reasons solar interconnection applications get bounced
Code-rooted patterns across California — not a city-specific rejection rate.
- 120% rule violation at the main panel without a supply-side tap or main-breaker derate
- Single-line diagram missing or inconsistent with the cut sheets
- Rapid-shutdown initiation and labeling not shown per NEC 690.12
- Conductor / OCPD sizing not at 125% of the inverter's max output current
- Structural attachment / roof-load calc missing for roof-mounted systems
- No grounding/bonding detail for the array and module frames (EGC + WEEB or listed clip)
- Battery storage proposed without Article 706 scope (separate disconnect, signage, listing)
The inspection sequence
A typical order — the number of stops and exact sequence vary by jurisdiction and scope.
- 1Rough inspection if any conduit or wiring is concealed before cover
- 2Final inspection with the system installed, labeled, energized into a test load, and rapid-shutdown verified
- 3Utility permission-to-operate (PTO) granted separately by the utility after city sign-off
Licensing — who can pull it
Solar PV installations in California are performed by a C-10 (Electrical) or C-46 (Solar) licensed contractor; a B (General Building) contractor may pull within a larger project under CSLB rules. C-46 is solar-specific; C-10 covers solar as electrical work. The licensed contractor pulling the permit typically also files the utility interconnection.
How this works in your California city
Cities marked have verified local data — portal, fee schedule, and adopted code edition sourced from public city documents. Others link to the general electrical permit guide for that city.
Frequently asked questions
How does SolarAPP+ change the permit process in California?
SolarAPP+ is a state-encouraged automated plan-review tool many California cities have adopted for residential solar (and increasingly storage) under the state's expedited-permitting laws. For code-compliant designs, it issues a permit instantly or same-day. Cities not using SolarAPP+ still must process residential solar permits on expedited timelines.
Do I need a separate permit for battery storage?
Battery storage adds NEC Article 706 scope — additional disconnect, signage, listing requirements, and often a separate or combined permit. Many cities bundle PV+ESS into a single permit; others issue them separately. Storage retrofits to existing PV are a permit on their own.
What is the 120% rule?
NEC 705.12 limits how much PV current can be backfed through the main-panel busbar: the main breaker + PV breaker cannot exceed 120% of the busbar rating. When that fails, options are derating the main breaker, a line-side (supply-side) tap, or upgrading the panel. This is the single most common solar-permit gotcha.
Who handles the utility interconnection?
The contractor typically files the utility's interconnection application (PG&E, SCE, LADWP, SDG&E, etc.) in parallel with the city permit. City sign-off is required for the utility to grant permission-to-operate (PTO) — the system shouldn't be energized to the grid until PTO is issued.
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