Environmental Impacts of PV Systems – SS3 Solar Photovoltaic Installation & Maintenance Lesson Note (First Term)

The environmental impact of a solar PV system covers its full life cycle: manufacturing, operation and end of life. A panel gives off no smoke or poisonous gases while it works, but its materials, including aluminium, glass, silicon and trace metals, must be recycled or disposed of properly so old panels do not pollute soil and water.

Behavioural objectives

By the end of the lesson, students should be able to:

• State the three stages of the full life cycle of a solar panel.
• List the main materials inside a solar panel.
• Describe the four steps used to recycle a solar panel.
• Explain why solar waste should not be thrown into a regular dustbin or into the bush.
• Describe ways of reducing the environmental impact of solar panels, such as second-life use and Extended Producer Responsibility (EPR).

Is solar energy really “green”?

We often hear that solar energy is “clean” and “green”. This is true because, while a solar panel is sitting on your roof, it does not smoke, it does not smell, and it does not release poisonous gases.

However, to be a professional solar technician, you must look at the full life cycle of a panel. This means looking at:

1. How it is made (manufacturing).
2. How it is used (operation).
3. What happens when it “dies” (end of life).

The big question: If solar panels help us save the planet today, how do we make sure they do not become a mountain of trash tomorrow?

How do we recycle a solar panel?

A solar panel is like a “sandwich” made of different materials glued together. To recycle it, we have to “un-make” the sandwich.

The recycling process

1. Frame removal: The aluminium frame is unscrewed. Aluminium is 100% recyclable and can be melted down to make new frames or even soda cans.
2. Cable stripping: The copper wires are removed. Copper is very valuable and easy to reuse.
3. Glass shredding: The big sheet of glass is crushed. It is hard to make “new” solar glass from it, but it can be used for fibreglass or road paint.
4. Silicon recovery: The actual solar cells are treated with chemicals to get the silicon and silver out.

What is inside a solar panel?

To understand the environmental impact, we need to know what a panel is made of. Most solar panels contain much more than glass.

The ingredients

• Glass: About 75% of a panel’s weight. It is harmless but heavy.
• Aluminium: Used for the frame. Mining it takes a lot of energy.
• Silicon: The “brain” of the cell.
• Polymers (plastic): Used to seal the panel from rain.
• Trace metals: This is the sensitive part. Panels contain small amounts of silver, lead, and sometimes cadmium.

The risk

If a panel is smashed and thrown into a regular dustbin, rain can wash those trace metals into the soil and eventually into our drinking water. This is why we never treat solar waste like regular kitchen waste.

Why is solar waste (e-waste) a challenge?

Solar panels are built to be very tough. Most last between 25 to 30 years. Solar power became popular in Nigeria only recently, so we have not yet seen the “mountain of waste”, but it is coming.

• Volume: Millions of panels are being installed every year. Eventually, they will all reach their end.
• Toxic components: Some older or cheaper panels use lead-based solder. If left in a landfill, this can be toxic to plants and animals.
• Informal disposal: In many places, people break the panels to get the aluminium frame and throw the “heart” of the panel (the silicon and glass) into the bush. This wastes valuable materials.

How can we build a sustainable solar future?

Sustainability starts with reducing and reusing, and recycling comes after that.

Better ways to manage solar impact

1. Second-life solar: A panel that produces only 70% of its original power is not “dead”. It can be donated to a village school or used for small tasks like charging phones.
2. Design for recycling: Scientists are now trying to make panels that are easier to pull apart without using harsh chemicals.
3. Extended Producer Responsibility (EPR): This is a policy where the companies that sell the panels are legally responsible for taking them back when they stop working.

Solar energy is our best tool against climate change, but we must use it responsibly. Recycling and managing waste properly keep “clean energy” clean from start to finish.

Class discussion

• If you see a neighbour throwing a cracked solar panel into a burning trash pile, what would you tell them about the smoke and the soil?
• Do you think Nigeria should have a “Solar Take-Back” law? Why?

Evaluation

1. Name the three stages of the full life cycle of a solar panel.
2. List the five main materials in a solar panel.
3. Describe the four steps of recycling a solar panel.
4. Why should a smashed solar panel never be thrown into a regular dustbin?
5. What is Extended Producer Responsibility (EPR)?

Assignment

1. Explain how a solar panel with 70% of its original power can still be useful (second-life solar).
2. Write a short paragraph explaining why informal disposal of solar panels is a problem.