Professional Solar Energy Installations training Examination

A PV module has Pmax 288 W, Voc 40.0 V, Isc 9.5 A. At STC when loaded, Vmp = 32 V and Imp = 9.0 A. You must design an array of 6 modules in series and 4 strings in parallel. What is the expected system kWp, array voltage, and current at STC?

• 5.76 kWp, 240 V, 38 A

• 5.76 kWp, 240 V, 38 A

• 6.912 kWp, 192 V, 9 A

• 6.912 kWp, 192 V, 36 A

• 7.0 kWp, 192 V, 36 A

For a grid‑tied system, the designer needs 40 kWh/day with average irradiance 5 peak sun hours and must account for 25% total losses. What PV array STC power is required?

• 13.333 kW

• 8 kW

• 9.411 kW

• 133.33 kW

• 10.667 kW

A rooftop 5 kW STC system has a performance ratio (PR) of 0.78. If the annual reference insolation is 1500 kWh/kWp, estimate the annual energy yield.

• 585 kWh

• 7500 kWh

• 5850 kWh

• 6750 kWh

• 7.5 kWh

A system uses microinverters per module. Shading reduces a single module to 50% of its MPP. Compared with a string inverter under the same shading, what happens to system performance?

• Microinverters suffer more loss.

• Microinverters limit the loss to that module only; a string inverter sees the whole string loss.

• Both systems are identical.

• Microinverters cut the whole system to 50%.

• None of the above.

A PV array with Voc per module = 48 V is connected 10 in series, with 8 strings in parallel. The maximum possible string Isc at STC is 9.0 A. What is the maximum short‑circuit current that the combiner fuse must handle instantaneously (nearest value)?

• 72 A

• 90 A

• 9 A

• 72 mA

• 8 A

When designing a utility‑scale PV array for minimal degradation over time, which module characteristic should most influence orientation, stringing, and shading mitigation decisions?

• Nameplate STC efficiency

• Low‑light performance

• Temperature coefficient of power and voltage

• Aesthetics of module frames

• Manufacturer warranty length

A mini‑grid with 30 kWh daily load requires 2 days of autonomy. If allowable depth of discharge (DoD) is 80%, estimate the total battery bank capacity at 48 V (approximate).

• 1300 Ah

• 1560 Ah

• 900 Ah

• 800 Ah

• 2000 Ah

In hot, humid tropical climates, which PV mounting decision will most improve long‑term yield and reduce BOS maintenance?

• Minimizing roof ventilation under modules

• Installing modules flush to roof to reduce wind uplift

• Painting module backs to reflect heat

• Using ventilated elevated mounts with corrosion‑resistant fasteners

• Using only glass‑back modules

When integrating bifacial modules into a mixed plant, what is the primary planning consideration to preserve expected bifacial gain?

• Install at the tallest possible tilt without regard to land use.

• Ignore albedo and ground conditions; bifacial gains are stable.

• Model and control ground albedo, row spacing, and elevation to manage rear irradiance.

• Place bifacial modules only east‑west.

• Use bifacial modules only on single‑axis trackers.

A 48 V solar charge controller must handle an array of 4 parallel strings, each with Imp = 9.5 A. With a 25% safety margin, what minimum controller current rating should be selected?

• 38 A

• 45 A

• 50 A

• 60 A

• 80 A