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

  1. What is the standard test condition (STC) irradiance level used when rating PV module output?

    Answer: 1,000 W/m²

    STC specifies 1,000 W/m² irradiance, 25°C cell temperature, and AM 1.5 spectrum as the reference conditions for rating PV module output.

  2. A battery-based off-grid system needs to power a 1,200W load for 6 hours daily. What is the minimum daily energy storage requirement?

    Answer: 7,200 Wh

    Daily energy requirement = 1,200W × 6 hours = 7,200 Wh, which sets the minimum usable battery capacity needed per day.

  3. When determining the number of modules per string for a string inverter, which inverter specification sets the upper boundary?

    Answer: Maximum DC input voltage

    The inverter's maximum DC input voltage (e.g., 600V or 1000V) caps the number of modules in series, as string Voc must not exceed this limit.

  4. What is the significance of a module's 'fill factor' (FF)?

    Answer: It indicates how closely the module's I-V curve approaches an ideal rectangle

    Fill factor is the ratio of maximum power to the product of Voc and Isc, showing how 'square' the I-V curve is and reflecting overall cell quality.

  5. A grid-tied PV system must include anti-islanding protection. What is the primary reason for this requirement?

    Answer: To protect utility workers from energized lines during an outage

    Anti-islanding prevents the inverter from continuing to energize the grid during a utility outage, protecting lineworkers who may be repairing downed lines.

  6. In PVWatts or similar simulation tools, what does the 'system losses' percentage account for?

    Answer: All real-world derating factors including wiring, soiling, shading, and mismatch losses

    System losses in tools like PVWatts represent a combined derate factor encompassing inverter, wiring, soiling, mismatch, shading, and other real-world losses.

  7. What is the purpose of including a DC disconnect switch between the PV array and the inverter?

    Answer: To allow safe isolation of the DC source for maintenance and emergency shutoff

    The DC disconnect allows maintenance personnel and emergency responders to safely de-energize the DC side of the system without disturbing the inverter or AC side.