Advanced PV Technologies SS3 Solar Photovoltaic Installation & Maintenance Lesson Note

Subject: Solar Photovoltaic Installation and Maintenance 

Class: SS 3 

Topic: Advanced PV Technologies

Objectives 

• By the end of this lesson, students should be able to explain how bifacial panels work.
• Describe what a solar tracker does
• Compare both technologies with a standard fixed panel.

BIFACIAL SOLAR PANELS

A normal solar panel only collects sunlight from the top. A bifacial panel collects from both the front and the back.

The back gets light from reflections off nearby surfaces — white walls, concrete, sand, or a light-coloured rooftop. The more reflective the surface underneath, the more energy the back captures. Scientists call this reflectivity albedo.

Bifacial panels typically produce 10% to 30% more electricity than regular panels of the same size.

Advantage: More output without adding more panels. Limitation: They need open space and a reflective surface underneath. Mounting them flat on a dark rooftop wastes the rear side entirely.

SOLAR TRACKERS

A standard panel stays in one fixed position all day. But the sun moves — it rises in the east, crosses the sky, and sets in the west. When sunlight hits a panel at an angle instead of straight on, the panel produces less electricity.

A solar tracker is a motorised mount that rotates the panel to follow the sun throughout the day, like how a sunflower turns toward light.

There are two types:

Single-axis tracker — rotates east to west, following the sun’s daily movement. Produces about 15–25% more than a fixed panel.

Dual-axis tracker — rotates east-west AND tilts up and down to follow seasonal changes in the sun’s height. Produces up to 40% more than a fixed panel, but costs significantly more.

Quick Comparison

Worked Example

A school has 10 panels, each producing 300W. They switch to bifacial panels that gain an extra 20% from reflected light. What is the new total output?

Standard output = 10 × 300 = 3,000W Extra from bifacial = 20% × 3,000 = 600W New total = 3,600W

Class Questions

1. Why would a bifacial panel not work well if mounted against a dark wall?
2. What is the main difference between a single-axis and dual-axis tracker?
3. A 4kW solar array gains 25% more output after installing a tracker. What is the new output?

Summary Bifacial panels earn extra electricity from reflected light on their back surface. Solar trackers earn extra electricity by keeping panels pointed directly at the sun. Used together, both technologies can push output 40–60% above a standard fixed panel.