NABCEP Cheat Sheet 2026

The 30 highest-yield NABCEP facts, distilled from real exam questions. Print it, save it as a PDF, or study it here — free, no sign-up.

1. What is the primary consideration when selecting the orientation of PV modules in the Northern Hemisphere? → South
2. What document does a utility typically require before allowing a customer-owned small wind system to connect to the grid? → An executed interconnection agreement
3. What is the minimum required clearance around battery energy storage systems for maintenance access per NFPA 855? → 36 inches on service side, per equipment labeling and local AHJ requirements
4. Which document should a commissioning technician provide to the system owner at project closeout? → As-built drawings, system manual, and commissioning report
5. What is the primary hazard when performing maintenance on a PV array that cannot be fully de-energized by shutting off the inverter? → PV modules continue to produce DC voltage in daylight even with the inverter off
6. What is the typical depth of discharge (DoD) limit recommended to maximize cycle life in lithium-ion battery storage systems? → 80–90% DoD as the operational maximum
7. An inspector finds that PV module mounting hardware is not listed for the specific roof type (e.g., tile roof). What action is appropriate? → Fail the inspection and require listed hardware appropriate for the roof type
8. Which heat transfer fluid is commonly used in closed-loop solar thermal systems to prevent freezing? → Propylene glycol-water mixture
9. What type of generator is most commonly used in small wind turbines? → Permanent magnet alternator
10. Which IEC standard governs the design requirements and safety of wind turbines used in small wind energy system applications? → IEC 61400-2 (Design requirements for small wind turbines)
11. What is the Rayleigh distribution used for in small wind site assessment? → Modeling the statistical frequency of wind speeds at a site
12. What interval is typically recommended for a full preventive maintenance inspection of a commercial grid-tied PV system? → Annually, at minimum
13. How does temperature affect the performance of PV modules? → Higher temperatures decrease module efficiency
14. What is the typical warranty cycle life for a quality residential lithium-ion battery storage system? → 4,000–6,000 cycles or more
15. Which NEC article specifically governs the installation of small wind electric systems? → Article 694
16. Which NEC article specifically addresses energy storage systems (ESS) including battery installations? → NEC Article 480
17. What is the purpose of a shading analysis during the design phase of a PV system? → To identify potential obstructions that could reduce system performance
18. When sizing a battery storage system for self-consumption optimization, what load data is most critical? → Historical hourly load profile of the facility
19. A combiner box fuse blows repeatedly in the same string position. What is the most appropriate next step? → Inspect the string for a ground fault or short circuit
20. Which battery chemistry is currently most common in utility-scale and residential energy storage systems in the US? → Lithium iron phosphate (LFP) and other lithium-ion chemistries
21. At what reference wind speed are small wind turbines typically rated for power output per IEC 61400-2 and AWEA standards? → 24.6 mph (11 m/s)
22. Which federal agency must be notified for wind turbine installations that exceed certain heights near airports or in navigable airspace? → FAA (Federal Aviation Administration)
23. What does 'wind rose' data tell a site assessor? → The frequency and speed distribution of wind from each compass direction at a site
24. What maintenance task should be performed on PV module surfaces in dusty or arid climates more frequently than in other regions? → Cleaning to remove soiling
25. When performing a site assessment, why is it important to consider shading analysis? → To identify potential obstacles that could reduce system performance
26. What document establishes the maximum allowable energy capacity of battery energy storage systems installed in residential occupancies? → NFPA 855 Standard for the Installation of Stationary Energy Storage Systems
27. During maintenance, you discover arc marks inside an outdoor DC combiner box. What should you do first? → De-energize the affected circuits and identify the cause before restoring power
28. Why is it important to consider local building codes and regulations when designing a PV system? → To avoid penalties and ensure the safety and compliance of the installation
29. What grounding requirement applies to metal towers used for small wind turbines? → Towers must be connected to the system equipment grounding conductor
30. What is the primary purpose of a commissioning inspection for a newly installed PV system? → To verify the system operates safely and as designed before handover