Practice Test Geeks(NABCEP) North American Board of Certified Energy Practitioners Solar Practice Test
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Solar PV Fundamentals 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 Solar PV Fundamentals flashcards as text

  1. What is the purpose of a blocking diode in a PV string connected to a battery system?

    Answer: To prevent battery current from flowing backward through the PV string at night

    Blocking diodes prevent reverse current flow from the battery back through the PV modules when the array voltage is lower than battery voltage.

  2. An array has 4 strings of 10 modules each wired in parallel. If each module is rated at 8A Isc, what is the total array Isc?

    Answer: 32 A

    In parallel strings, currents add: 4 strings × 8 A per string = 32 A total array Isc.

  3. What effect does partial shading of a single module in a series string have on overall string output without bypass diodes?

    Answer: The entire string current is limited to the shaded module's reduced current

    In a series string, all modules must carry the same current, so a shaded module limits the current for the entire string.

  4. Which of the following best describes the AM1.5 spectrum used in STC module ratings?

    Answer: Sunlight passing through 1.5 times the atmosphere's thickness at a 48.2° angle

    AM1.5 represents the solar spectrum when sunlight travels through 1.5 air masses (a path length 1.5× the zenith path), corresponding to a solar angle of about 48.2°.

  5. A PV module has a Voc of 40V at 25°C and a temperature coefficient of -0.3%/°C. What is the approximate Voc at 60°C?

    Answer: 35.8 V

    ΔT = 35°C; voltage change = 40V × 0.003 × 35 = 4.2V decrease; Voc ≈ 40 – 4.2 = 35.8V.

  6. What is the primary advantage of monocrystalline silicon modules compared to polycrystalline silicon modules?

    Answer: Higher conversion efficiency due to uniform crystal structure

    Monocrystalline cells have a single uniform crystal lattice with fewer grain boundaries, yielding higher efficiency than polycrystalline cells.

  7. In thin-film PV technology, what property allows the active semiconductor layer to be much thinner than crystalline silicon cells?

    Answer: Direct bandgap enabling strong light absorption with less material

    Direct-bandgap semiconductors like CdTe and CIGS absorb photons very efficiently, requiring only a few microns of material versus ~180 microns for silicon.