Free practice questions for the California CSLB C-46 Solar trade exam — with a written explanation on every answer, in English, Spanish, and Russian.
The C-46 Solar exam is the trade exam for California contractors who install, modify, maintain and repair thermal and photovoltaic solar energy systems. CSLB's official study guide splits it into six sections, weighted from 7 percent for solar thermal up to 28 percent for photovoltaic installation and commissioning, with safety close behind at 19 percent. Practice it below — free, no sign-up, with a written explanation on every question.
No account needed. Pick an answer to see whether it's right and read the explanation — the same explanations you get on every question in the full course.
Every question tells you why the correct answer is correct and defines the terms it uses — so you learn the rule, not just the answer.
Questions are written from scratch against the official codes and agency publications for this exam — never copied from the real exam.
Every question and explanation is fully translated, with the English exam term kept alongside — not a shallow machine translation.
LICENA is a practice tool, not a school. We don't promise a pass — we help you understand the material and walk in prepared.
The full CSLB C-46 Solar course is 500 questions across 5 blocks, drawn from these six official sections.
About 14 percent of the exam. You evaluate a client's needs and the site, design and engineer the system, read plans and estimate the job: shading, orientation and tilt, structural capacity, and what the customer's utility bill actually shows. California adds a layer no other state has — the Energy Code (Title 24, Part 6) prescriptively requires a solar photovoltaic system on newly constructed buildings, and where an exception applies the building must still meet the mandatory solar-ready requirements. The trap is assuming that "no PV required here" means nothing is required.
Roughly 17 percent: roof-mount and ground-mount collectors, and weatherproof penetrations. The California-specific trap is fire access. On a one- or two-family dwelling the Fire Code demands a clear setback on both sides of a horizontal ridge — at least 18 inches where the array covers 33 percent or less of the plan-view roof area, at least 36 inches above that. Where the dwelling has an approved automatic sprinkler system those coverage thresholds move up to 66 percent, so read every question for whether sprinklers are mentioned.
The biggest section at 28 percent, and where most of your study time belongs. It covers basic and standalone PV systems, energy storage systems, interfacing with the utility grid, labeling, and system testing, configuration and monitoring. Two rules recur. Rapid shutdown: outside the array boundary — one foot from the array in all directions — controlled conductors must fall to 30 volts or less within 30 seconds of initiation. Interconnection: under the 120 percent rule, 125 percent of the inverter output current plus the main breaker rating may not exceed 120 percent of the busbar rating, with the PV breaker at the far end of the bus. On a 200-amp bus behind a 200-amp main, that leaves 40 amps.
Only 7 percent, but cheap points if you give it an evening: hot water systems and pool heating. Learn the difference between the two ICC-SRCC programs, because rebate and permit paperwork turns on it — OG-100 certifies a single collector after laboratory testing, OG-300 certifies a complete solar water heating system with its tank, pump, heat exchanger and controls. Understand why a pool collector runs unglazed and uninsulated, since it only lifts water a few degrees above ambient, while a domestic hot water collector is glazed and insulated.
About 15 percent: evaluating PV and thermal systems and replacing components. These are diagnosis questions, not installation questions. One benchmark carries a lot of them — NREL's review of nearly 2,000 field measurements puts median module degradation near 0.5 percent per year, so an older array a few percent under nameplate is ageing normally, while a large drop is a fault to chase: soiling, new shade, a failed module-level device, a corroded connector.
19 percent, the second-largest section, and the one candidates under-prepare because it feels like common sense. It is Cal/OSHA law, and California is stricter than the federal standard: fall protection is required above 7 1/2 feet of exposure — not the federal 6 feet — and on roof slopes steeper than 7:12. Add handling hazardous materials, correcting unsafe conditions and protecting the public below the work. If you are also studying C-10 Electrical, the electrical-safety reasoning overlaps heavily.
C-46 Solar is a closed-book, multiple-choice exam with four choices per question, taken on a computer at a PSI testing center. CSLB's official C-46 Solar study guide states that only one choice is the best answer, that some questions require calculation, that a calculator is provided, and that there is no penalty for guessing. CSLB's Examinations FAQ gives 3.5 hours per exam, a pass/fail result at the center, a section-by-section breakdown on a failing report, and a retake after 21 days within your 18-month application window. CSLB publishes official Spanish versions of ten exams and C-46 is not one of them, so this exam is taken in English; for exams with no Spanish version CSLB permits an approved translator. Most first-time applicants also sit the Law and Business exam.
The LICENA C-46 course is 500 questions across 5 blocks. At 30 a day that is roughly three weeks — two passes with room to re-drill your weakest block. Weight your hours the way the exam weights itself: PV installation and commissioning plus safety are 47 percent of the test between them, while solar thermal is 7. Read the explanation on every question you miss, because the exam rewords facts; knowing that the ridge setback is 18 inches at 33 percent coverage survives any wording, while a memorized answer letter does not. Pair the practice with CSLB's own study guide and the current California Electrical, Fire and Energy Codes. No question bank can promise you a pass — anything that does is selling you something.
The full 500-question C-46 Solar bank with a written explanation on every answer, weak-area practice and a timed final exam, in EN·ES·RU. California exam-prep schools list programs from about $250 to $1,200 — this is $20/month, on your phone, cancel anytime.
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LICENA provides online practice only. Registration, exam scheduling and licensing are handled by the CSLB and its exam vendor PSI — not by LICENA. LICENA is not affiliated with the CSLB or PSI.