The Solar Installation Process in California, Step by Step

The survey decides two things that can reshape the project. An aging roof is cheaper to replace before the array goes on than to reach later by removing and reinstalling it (replace your roof before solar?). A full or small electrical panel may need an upgrade, depending on the code edition, the utility and the equipment (do you need a main panel upgrade?). The design then depends on your utility: SCE, PG&E and SDG&E customers are on the Net Billing Tariff, where a battery that stores midday solar often pays (NEM 3.0 explained); LADWP runs its own net metering, where a battery is mainly backup.

• Solar disclosure document. Every solar contract must carry the state’s disclosure on its front or cover page, in 16-point bold type: total cost and payments including financing, where to complain, and your cancellation right (B&P §7169).
• CPUC Solar Consumer Protection Guide. In the territories of PG&E, SCE, SDG&E, Bear Valley, PacifiCorp and Liberty, the installer must collect your initials and signature on the guide, and you must be given time to read it (CPUC). LADWP is not on that list.
• Right to cancel. A contract signed away from the seller’s place of business can be cancelled until midnight of the third business day after you receive a signed, dated copy, the fifth if you are 65 or older (Civil Code §1689.6).
• Payments. The down payment is capped at $1,000 or 10% of the price, whichever is less; payments may not run ahead of the work; the contract must name who obtains the permits and give a completion date (CSLB).
• Tax credit. The 30% federal Residential Clean Energy Credit ended for expenditures after December 31, 2025, so a cash or loan purchase in 2026 gets no federal credit (IRS).

For the full list of rights, see your solar consumer rights.

Every city and county runs its own permit counter. In the City of Los Angeles, every PV system needs an electrical permit; a system of 10 kW or less on a one- or two-family home, on a panel of 225 A or less and meeting LADBS’s other express criteria, is issued online as an express permit with no plan check, and a separate building permit is needed only if the array misses LADBS’s structural exemption (P/GI 2026-003, P/GI 2023-027; details in solar permits in Los Angeles). After installation an inspector checks the work against the approved plans; the common reasons it fails are in why solar inspections fail.

The utility has its own review. SCE asks for the whole package at once — the application, single-line diagram, signed interconnection agreement and the final electrical permit approval from the building department — arranges any meter change before issuing PTO, and states that PTO is what authorizes you to operate the system; enrollment in the Solar Billing Plan follows within a few billing cycles (SCE). Requests with paired storage or non-standard metering need more review, and SCE publishes no figure for them. LADWP’s published stages — a site visit and location drawing, interconnection approval, verification of the installation, meter setting — add up to roughly three and a half to eight weeks of utility-controlled time, and only once the submission is complete (LADWP). The full breakdown is in permit to PTO in Los Angeles.

Figures on this page come from the primary sources below and, where noted, from Cali Energy calculations using the stated assumptions. Rates, incentives, and program terms change; each was verified September 29, 2026.

1. SCE — Solar Billing Plan FAQs (PTO within 10 business days for simple solar-only requests; package; meter change; PTO authorizes operation)
2. LADWP — Guide to Electric Service, March 2024, pp. 22–23 (solar process under 30 kW, stage durations)
3. CPUC — California Solar Consumer Protection Guide (signature requirement in IOU territories)
4. Business and Professions Code §7169 — solar energy system disclosure document
5. Civil Code §1689.6 — right to cancel a home solicitation contract
6. CSLB — Home improvement contracts (down payment, payments, permits, completion date)
7. LADBS — Information Bulletin P/GI 2026-003, Express Permits
8. LADBS — Information Bulletin P/GI 2023-027, Solar Energy Systems
9. IRS — Residential Clean Energy Credit