When you buy solar panels in Port Harcourt or Warri, a seller may ask: "Mono or poly?" Here is what that means.
What the words mean
Solar panels are made of small squares called cells. Cells are made from silicon.
- Mono (monocrystalline) cells are cut from one pure crystal. They are black.
- Poly (polycrystalline) cells are made from many small crystals melted together. They are blue and speckled.
Side by side
| Mono | Poly | |
|---|---|---|
| Colour | Black | Blue, speckled |
| Efficiency | About 20 to 23% | About 15 to 18% |
| Power per panel today | 450W to 600W+ | Usually under 350W |
| Heat | A little better | A little worse |
| Weak light / cloud | A little better | A little worse |
| Roof space needed | Less | More |
| Common in 2026 | Yes | Mostly old or cheap stock |
Why efficiency matters on a Nigerian roof
Many roofs in Port Harcourt and Yenagoa have water tanks, parapets and odd shapes. Space is limited. Mono panels give you more power from each square metre. So you can fit your system on a smaller roof.
Heat
Panels lose a little power when they get hot. Our sun is strong and our roofs get very hot. Mono panels lose slightly less in heat. Over 25 years, that adds up.
Price
Today, mono panels are not much more expensive than poly. Because they make more power, mono often costs less per watt. If someone offers very cheap poly panels, ask why. They could be old stock or used. Read new vs used (tokunbo) panels.
What we use
We install mono panels from trusted brands like Jinko and Longi. Our standard packages use 600W panels. See our prices.
Checklist before you buy
- Is it mono?
- What is the brand and model?
- Is there a datasheet?
- Is the power tolerance positive (0/+5W)?
- Is there a 25-year performance warranty?
More tips in how to spot fake solar panels.
