Solar (C-46) · Lesson 2 of 6

Commercial PV and Battery Sizing: Section 140.10

"Commercial PV and Battery Sizing: Section 140.10" is lesson 2 of 6 in the Solar (C-46) Learning Hub. It opens with "Which Buildings Must Have PV and a Battery" and works through 5 short steps, then a worked example you can check yourself against.

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Steps in this lesson

  1. Which Buildings Must Have PV and a Battery
  2. PV Capacity: Equation 140.10-A
  3. The SARA Cap and the Five Exceptions
  4. Battery Size: Equations 140.10-B, -C and -D
  5. Battery Exceptions and the Order of Work

The worked example in the course applies this lesson to a realistic job in 8 steps, from "SARA cap for a low-sloped roof" through "Battery exceptions".

What you'll be able to do

  • Explain the main idea of "Commercial PV and Battery Sizing: Section 140.10" in plain language you can use on the exam.
  • Apply this step with confidence: "The SARA Cap and the Five Exceptions".
  • Apply this step with confidence: "Battery Size: Equations 140.10-B, -C and -D".
  • Apply this step with confidence: "Battery Exceptions and the Order of Work".
  • Test yourself on the worked example and the quick-check quiz inside the classroom.
Commercial PV + Battery: Section 140.10BESSRetail, CZ 12, CFA 20,000 sq ftLow-slope SARA 4,000 sq ftTABLE FACTORS (RETAIL, CZ 12)Table 140.10-A: A =3.64 W/sq ftTable 140.10-B: B =1.95 Wh/sq ftBattery round-trip C = 0.90 (C^0.5 = 0.9487)PV (Eq. 140.10-A)(20,000 x 3.64)/1000 = 72.8 kWSARA cap: 4,000 x 14 = 56.0 kWPV = smaller = 56.0 kWdcBESS (Eq. 140.10-B, -C, -D)B: (20,000 x 1.95)/(1000 x 0.9487)= 41.11 kWhC: 41.11 x (56.0 / 72.8) = 31.62 kWhD: 31.62 / 4 = 7.91 kWdc powerExceptions checked: SARA is over 3% of CFA,PV is over 4 kW, BESS is over 10 kWh, andPV is 77% of Eq. 140.10-A (over 15%).All tests pass: PV and BESS required56.0 kWdc PV + 31.6 kWh / 7.9 kWdc battery minimumSource: 2025 California Energy Code Sec. 140.10(a), (b); Tables 140.10-A and 140.10-BCC
The diagram for this lesson, exactly as it appears in the Learning Hub.

The first steps of this lesson

Step 1: Which Buildings Must Have PV and a Battery

2025 California Energy Code Section 140.10(a) requires a newly installed PV system (meeting Joint Appendix JA11) on newly constructed buildings of the types listed in Table 140.10-A: events and exhibits, library, hotel/motel, office/financial institution/unleased tenant space/medical office building or clinic, restaurants, retail and grocery, school, warehouse, religious worship, sports and recreation, and multifamily over 3 stories. A mixed-occupancy building is covered where at least 80 percent of its floor area is one or more of those types; you apply the equation to each type's conditioned floor area and add the results. Section 140.10(b) then requires a battery energy storage system (BESS, meeting JA12) on any building that must have the PV system.

Step 2: PV Capacity: Equation 140.10-A

The minimum rated PV capacity is kWpvdc = (CFA x A)/1000, where CFA is conditioned floor area in square feet and A is the PV capacity factor in W per square foot from Table 140.10-A for the building type and climate zone. Example values from the table: Retail/Grocery in Climate Zone 12 is 3.64, School in Climate Zone 12 is 1.63, and Warehouse in Climate Zone 1 is 0.39. Dividing by 1000 turns watts into kW.

The remaining 3 steps, the worked example and the quiz are in the course. This is a preview. The full lesson, with the step-by-step explanations, a worked example and a quick-check quiz, is inside the classroom.

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