Main panel upgrade in Simi Valley, CA

• The permit. The City of Simi Valley Building & Safety issues the electrical permit. For a standard main panel upgrade the city runs an express route: self-issued and instant. On our October 2022 project the city moved the application onto it the same day, and we self-issued the permit and started without losing a day.
• The utility. A panel upgrade changes SCE's equipment too, so SCE reviews it first. Its planning office looks at the existing service, the meter position, the clearances and how the supply arrives, then returns a written approval and a yellow sticker on the panel with the conditions. Allow seven to ten business days.
• The inspection. When the panel and the array go in on the same visit, one inspection covers both. On our May 2022 project the array went in on a Wednesday and the final passed the following Monday, with no corrections.
• New solar in Simi Valley is going in with storage. Of the 962 residential solar systems SCE approved in Simi Valley from January 2025 to March 2026, 93.7% included a battery, and the median system was 8.2 kW. A battery needs the service to accept its connection, which is where the busbar question starts.

The electrical code caps the main breaker plus the solar breaker at 120% of the busbar rating. Put a 200-amp main in a 200-amp panel and the solar breaker fights for room; put it in a 225-amp panel and there is headroom by design. On our August 2022 Simi Valley upgrade we specified the larger busbar while the panel was being replaced anyway; the city approved the final, and the meter was released to the utility. How the busbar decides whether solar fits

A derate, a smaller main breaker, works when a load calculation shows the house can live on it. Derate, new panel or service upgrade

• A 225-amp busbar under a 200-amp main, specified during a panel replacement; city final approved, meter released. Read the project
• 12.8 kW on a 225-amp main panel, approved in minutes by the city's automated permit check; thirty-two modules with a microinverter under each. Read the project
• Installed Wednesday, passed Monday: panel upgrade and array in one visit, one inspection, no corrections. Read the project
• SCE's review of the panel: a site visit, a yellow sticker with the conditions, and a written approval the design was finalized against. Read the project
• The city's express permit for a panel upgrade, self-issued the same day; the panel went in and passed inspection. Read the project
• Solar, roofing and a panel upgrade in one project on a house with a patio structure, with the panel upgrade approved in place and no service relocation. Read the project
• Three scopes under one contract, solar, service panel and roofing, each written out so it could be accepted on its own; the roof passed its final and the array followed. Read the project

1. Check. Busbar rating, main breaker, open positions and a load calculation for the house.
2. SCE review. We request the meter spot; SCE returns its approval and the sticker on the panel.
3. City permit. Express for a standard panel upgrade; with solar, the plan set goes through the city's automated check or plan review.
4. Installation, scheduled with SCE for the reconnection, under our C-10 electrical license.
5. Final inspection, then the meter is released and, with solar, SCE grants permission to operate.

Nearby. Main panel upgrades in Santa Clarita · Woodland Hills · All our Simi Valley projects