SSCE Past Questions (Theory) SS3 Solar Photovoltaic Installation & Maintenance Lesson Note

Class: SS3

Subject: Solar Photovoltaic Installation and Maintenance

Topic: Step-by-Step Solutions to Common Theory Questions

Understanding “Sizing” Questions

One of the most common questions in the SSCE theory section asks you to “size” a system for a small house. They want to see if you can match the panels and batteries to the load.

The Question: A barber shop uses 2 clippers (15W each) for 4 hours a day and 3 LED bulbs (10W each) for 6 hours. Calculate the total energy used in Watt-hours (Wh).

The Worked Solution:

1. Clippers: 2×15W×4 hours=120Wh
2. Bulbs: 3×10W×6 hours=180Wh
3. Total: 120Wh+180Wh=300Wh

Exam Tip: Don’t just write “300.” Always show your addition and multiplication. Examiners give “Method Marks” even if your final answer has a small calculation error.

Troubleshooting and Maintenance Scenarios

The examiners often give you a “real-life” problem and ask you to fix it.

The Question: A customer complains that their solar lights stay on for only 2 hours at night, even though the day was very sunny. List three possible causes.

The Worked Solution:

1. Old/Weak Battery: The battery might be “tired” and can no longer hold a full charge (High internal resistance).
2. Dirty Panels: Dust or bird droppings on the panels are blocking the sun, so the battery never gets 100% full.
3. Loose Connections: A wire between the charge controller and the battery might be loose, preventing the power from flowing correctly.

Pro-Tip: Always suggest the “simplest” fix first (like cleaning the panels) before suggesting expensive fixes (like buying a new battery).

Comparing Solar Components

You will often be asked to “Distinguish” or “Compare” two things. Use a simple table or bullet points to make it easy for the marker to see your points.

The Question: Compare a PWM (Pulse Width Modulation) charge controller with an MPPT (Maximum Power Point Tracking) controller.

The Worked Solution:

Safety and Installation Rules

Safety is a “non-negotiable” topic. If you miss this, you lose easy marks.

The Question: Outline four safety precautions a technician must take when installing a 24V solar battery bank.

The Worked Solution:

1. Remove Jewelry: Take off metal rings or watches to avoid “short-circuiting” the battery terminals.
2. Use Insulated Tools: Use spanners and screwdrivers with rubber handles.
3. Ventilation: Ensure the battery room has fresh air (especially for Lead-Acid batteries that can release gas).
4. Terminal Covers: Always put the plastic “caps” over the battery heads after tightening the wires to prevent accidental sparks.

The “Big Picture” – Policy and Environment

These questions are usually at the end of the paper and ask about Nigeria’s energy situation.

The Question: Explain how “Rural Electrification” helps in reducing rural-to-urban migration in Nigeria.

The Worked Solution:

• Job Creation: With solar power, youths in villages can start businesses like barbing salons, phone charging centers, and cold-room storage for fish/crops.
• Education: Students can study at night, and schools can use computers, making village life more attractive.
• Safety: Streetlights powered by solar reduce crime at night, making people feel safe staying in their hometowns instead of moving to big cities like Lagos or Abuja.

Conclusion for Students: When you answer these, think about your own community. Use real examples of how light changes a person’s life!