Tag: avoid solar scams

Whenever we go to the market to buy solar panels, we get completely confused about which solar panel we should buy, how many watts we need, which technology is better. Apart from that, there are so many other questions in our mind about which we have zero knowledge.

Whenever we install a solar system, the most important part of the entire system is the solar panel. If you don’t select the right solar panel, then no matter how good the rest of the system (inverter, battery, wiring) is, it’s of no use.

That’s why when people decide to install solar, the top 5 questions they ask the most are the ones you should definitely know about.

1st most important point: Efficiency of solar panel

When you buy a solar panel, you must have seen it written on the panel — efficiency 14%, 15%, 20%, etc. What does this mean? Out of all the sunlight that falls on the panel, how much percentage of it is getting converted into electricity — that percentage is called efficiency.

2nd point: P-type vs N-type

Nowadays you hear the word N-type almost everywhere. Earlier it used to be mostly P-type, and many times they didn’t even mention it, just gave you the panel. Technically it’s a bit long to explain, but simply remember:

• P-type → old technology
• N-type → new & improved technology

N-type panels are much more efficient compared to P-type. The problems/weaknesses that were in P-type have mostly been removed in N-type.

But that doesn’t mean P-type panels are completely useless today. They had their time. Right now the latest panels coming in the market are almost all N-type. So just keep one thing in mind, whatever panel you buy today, make sure it is N-type.

3rd point: Watt rating

Since we buy solar panels to generate electricity, everything depends on how many watts the panel produces. For example: You see 500W, 540W, 550W panels in the market. If you want to install a 2 kW solar system, then you’ll need roughly four 540W panels (4 × 540 = 2160 W ≈ 2 kW+). So always calculate according to your required system size.

4th point: DCR vs Non-DCR

This is very simple to understand.

• DCR (Domestic Content Requirement) → panels manufactured in India
• Non-DCR → either fully imported or cells imported & assembled here (still counted as Non-DCR)

If you want subsidy under PM Surya Ghar Yojana (or any government scheme), then only DCR panels are eligible. Government is promoting Make in India, so they don’t give subsidy on imported / Non-DCR panels. So if subsidy is important for you → must buy DCR panels only.

5th point (most important — saved for last): A-grade vs B-grade
I’ll explain this at the end because it’s very critical.

Now let’s understand different types of solar panels in very simple language.

Evolution of solar panel technology (for home use):

1. Polycrystalline (first type, blue colour)
   • Efficiency: 13–16%
   • Oldest technology
   • Almost disappeared from market now
2. Monocrystalline
   • Efficiency: ~16–18% (2–3% better than poly)
   • Better temperature handling
   • Black colour mostly
3. Monoperc (PERC technology added)
   • Efficiency improved again (~1–1.5% more)
   • Cells improved → better performance
4. Monoperc Half-cut
   • Big improvement: cells are cut in half → panel divided into two electrical parts
   • Advantage: If shadow/dust falls on one half, the other half still works at full capacity
   • Earlier full-cell panels — even small shadow on one cell could reduce entire panel output drastically
   • Now you see 144 half-cells instead of 72 full cells
5. Bifacial (mostly comes with half-cut now)
   • Generates power from both front and back side
   • Front: 100%
   • Back: ~70% (albedo light — reflection from ground/roof)
   • Easy to identify: back side also looks like solar cells (not white sheet like normal panels)

So latest common name you hear today:
Monoperc Half-cut Bifacial N-type

1. Topcon (Tunnel Oxide Passivated Contact)
   • Even more advanced than previous
   • Higher efficiency, higher wattage in same size (550–700 W common now)
   • Usually N-type + Half-cut + Bifacial + Topcon
2. HJT (Heterojunction Technology) — latest of all (2024–2026 period)
   • Efficiency: 23–23.5%+ (highest so far)
   • Very high wattage panels starting from 700–750 W already
   • Still expensive & mostly imported in India → used more in commercial projects
   • In future expected to reach 1 kW per panel

Quick summary: What should you buy in 2025–2026?

Best realistic choice right now for home users (balance of price, performance, availability & subsidy): Topcon Half-cut Bifacial N-type DCR panels (550–700W range)

HJT is superb but still costly and less available in DCR.

Most important: A-grade vs B-grade

This is the point many vendors never tell you.

• A-grade: Perfect panel, no manufacturing defect, gives 100% rated output
• B-grade: Some manufacturing defect (example: one cell damaged, spot on glass, etc.), output slightly less (maybe 3–10W less per panel)

B-grade panels are sold cheaper. Vendors push them without telling. Over time their efficiency drops faster, long-term loss for customer.

How to check?

• Ask for flash test report (IV curve graph)
• Good companies stick the flash report graph on back of panel or give copy inside box
• Insist on A-grade only

Popular Indian brands right now (DCR eligible): Adani, Tata Power Solar, Waaree, Vikram Solar, Renewsys, etc.

Always cross-check price online + local market + company website. Don’t fall for very cheap “deal,” usually old stock or B-grade.