Practice Test Geeks(NABCEP) Certified North American Board of Certified Energy Practitioners Specialist Practice Test
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PV System Design Principles Flashcards

7 cards from real NABCEP practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

Read the first 7 PV System Design Principles flashcards as text

  1. The purpose of a module-level power electronics (MLPE) device such as a microinverter or DC optimizer is primarily to:

    Answer: Mitigate the impact of shading and mismatch on overall system output

    MLPEs allow each module to operate at its own maximum power point, reducing losses caused by shading, soiling, or module mismatch.

  2. For a roof-mounted residential PV array, which factor is most important when evaluating roof pitch for energy production?

    Answer: The angle's effect on tilt, which influences annual irradiance capture

    Roof pitch determines array tilt angle, which directly affects how much solar irradiance the modules intercept throughout the year.

  3. A combiner box in a large PV array is used to:

    Answer: Combine multiple source circuits into a single output circuit with overcurrent protection per string

    A combiner box parallels multiple strings, providing fuse or breaker protection for each source circuit before connecting to the inverter.

  4. According to NEC 690.12, rapid shutdown of a PV system is required primarily to:

    Answer: Reduce voltage in roof-mounted conductors to protect first responders

    Rapid shutdown requirements protect firefighters and other first responders from energized conductors on and near the roof.

  5. The term 'specific yield' in PV system performance refers to:

    Answer: Annual energy production per kilowatt of installed DC capacity (kWh/kWp)

    Specific yield, expressed in kWh/kWp, normalizes annual energy output to system size and enables comparison across different system sizes and locations.

  6. When calculating the maximum number of modules per string, the designer must consider the module's Voc at:

    Answer: The lowest expected ambient temperature at the site

    Module Voc increases as temperature decreases, so the coldest expected temperature produces the highest string voltage, which must remain within inverter limits.

  7. What is the primary advantage of a central inverter compared to multiple string inverters in a large commercial PV system?

    Answer: Lower cost per watt and simpler maintenance at a single location

    Central inverters typically have a lower cost per watt and consolidate maintenance at one location, making them economical for large uniform arrays.