Monocrystalline vs Polycrystalline Solar Panels: Which One is Better For Indian Rooftops, and Why?

Unlike polycrystalline solar panels, which are made of multiple silicon crystals and deliver lower efficiencies of 16-17%, the latest monocrystalline solar panels made of half-cut PERC cells can reach high efficiencies of up to 22.5%. Monocrystalline panels also tend to degrade more slowly, often at ~0.5% per year, while some polycrystalline modules may degrade at ~0.8% per year under harsher conditions. Over 25 years, the difference in output and savings becomes huge.

Due to their lower efficiency, faster degradation rate, and higher temperature coefficient than that of mono panels, polycrystalline solar panels are now almost obsolete in India. They are rarely used to build new rooftop solar panel systems for homes, housing societies, and commercial buildings because bifacial solar panels made of mono-PERC half-cut cells offer a better ROI, faster payback, and better performance over the years.  

Monocrystalline solar panels are made using a single-crystal silicon ingot, which allows electrons to move more freely, reducing resistive losses. Recent PERC (Passivated Emitter and Rear Cell) innovations, combined with half‑cell cuts, further reduce losses at the back side and in low light, pushing module efficiencies to up to 22.5%, beyond older mono panels that often achieved 19‑20% efficiency. 

Upfront installation cost was traditionally the only drawback for mono panels, but it’s no longer a problem because the government offers a maximum subsidy of Rs. 78,000 to homeowners and a maximum subsidy of Rs. 90 lakh to housing societies that install on-grid rooftop solar panel systems. Plus, solar loans from banks and reducing module prices have made it extremely affordable for anyone to install rooftop solar systems. 

When you compare the total installation cost against lifetime savings over a 25‑year system life, a well‑designed bifacial rooftop system in India with mono-PERC half-cut cells delivers returns many times the investment. No other form of investment can ever offer such high returns, except for rooftop on-grid solar systems.

In this blog on monocrystalline vs polycrystalline solar panels, we will explain the major difference between monocrystalline and polycrystalline panels, offer a detailed ROI breakdown against the cost of installing an on-grid rooftop solar system in India in 2025, and talk about the reasons why monocrystalline solar panels with PERC half-cut silicon cells are the best choice for Indian rooftops. 

TL;DR Summary Box: Which is Better, Monocrystalline or Polycrystalline Solar Panels?

Monocrystalline solar panels with PERC half-cut solar cells are hands down the better option when compared to polycrystalline solar panels because they perform better in shade due to the cell’s half-cut design, have a higher efficiency of 22.5%, feature a lower temperature coefficient that improves their performance in heat, and have a lower degradation rate, which means they perform at higher efficiency than poly panels even after 25 years.

Here are the main topics covered in this blog in detail:

What Are Monocrystalline and Polycrystalline Solar Panels?

The main difference between mono and poly solar panels exists in the structure of silicon that’s used to make their respective cells. Monocrystalline panels are made from a single crystal of silicon. It allows electrons to move more freely and makes the panel more efficient. Polycrystalline panels, on the other hand, are made by melting together many silicon fragments. It reduces efficiency because the movement of electrons gets disrupted.

• Polycrystalline solar panels: They’re made by melting multiple silicon fragments together. This process is less expensive but creates more grain boundaries within the cell, which reduces its efficiency.
• Monocrystalline solar panels: They’re made from a single crystal silicon ingot. Since the silicon structure is uniform, electricity flows more easily, resulting in higher efficiency and better performance in heat and shade.

What is a Monocrystalline Solar Panel?

A monocrystalline solar panel is made using a single, continuous silicon crystal. These panels are black in color and offer an efficiency range of 19% to 20%. The efficiency reaches up to 22.5% in advanced mono panels with PERC half-cut cells. These panels also perform well in low-light, high-temperature, and partially shaded conditions.

Here’s a step-by-step guide on how monocrystalline solar panels are manufactured: 

• Step 1 – Silicon ingot growth: A single-crystal silicon ingot is grown using the Czochralski process.
• Step 2 – Wafer slicing: The cylindrical ingot is sliced into thin wafers using diamond wire saws.
• Step 3 – Wafer doping: The wafers are doped with chemicals to improve electrical conductivity.
• Step 4 – PERC layer addition: A passivation layer is added to the rear side to reflect unabsorbed light.
• Step 5 – Half-cut cell design: Each full cell is cut into two halves to reduce energy loss and improve shade tolerance.
• Step 6 – Panel assembly: The half-cut monocrystalline PERC cells are connected and laminated to create the final panel.

What is a Polycrystalline Solar Panel?

Unlike monocrystalline solar panels that use a single silicon ingot, polycrystalline solar panels are made by fusing multiple silicon crystals together. These panels are usually blue, have a lower efficiency of 16-17%, and feature a higher degradation rate compared to monocrystalline panels.

Here’s a quick step-by-step guide explaining how polycrystalline solar panels are made:

• Step 1 – Silicon melting: Recycled or raw silicon fragments are melted down in a crucible.
• Step 2 – Casting in a mold: The melted silicon is poured into a square mold and cooled to form a large block.
• Step 3 – Wafer slicing: The silicon block is cut into thin square wafers.
• Step 4 – Cell formation: Each wafer is treated and doped to form photovoltaic cells.
• Step 5 – Panel assembly: The poly cells are wired, laminated, and framed to form the solar panel.

What is the Difference Between Monocrystalline and Polycrystalline Solar Panels?

The main difference between monocrystalline and polycrystalline solar panels is that the former is made of a single silicon ingot, which results in a higher efficiency of 19-20%. When a PERC layer is added and the cells are cut in half, the efficiency shoots up to 22.5%. Poly panels, on the other hand, are made of multiple fragments of silicon and have a lower efficiency of 16-17%.

A Cursory Glance at Monocrystalline vs Polycrystalline Solar Panels

Before we take you deeper into the difference between mono and poly solar panels, here’s a simple table that demonstrates how these panels truly differ across various features:

Now, let’s compare the differences between monocrystalline and polycrystalline solar panels in greater detail.

Efficiency of Mono vs Poly Solar Panels

The efficiency of a solar panel determines how much sunlight it can convert into usable electricity. Monocrystalline panels deliver higher efficiency (19-22.5%) because of their single-crystal structure, while poly panels have lower efficiency (16-17%) due to the use of fragmented silicon.

Let’s check out all the main factors regarding the difference between the efficiency of mono vs poly solar panels.

• Silicon structure: Mono panels are made from a single silicon crystal, which lets electrons move smoothly. Poly panels have multiple grain boundaries that interrupt the electron flow, lowering efficiency.
• PERC layer advantage: Adding a Passivated Emitter and Rear Cell (PERC) layer in mono panels reflects unused light back into the cell. It boosts their efficiency to ~22.5%. Poly panels lack this upgrade.
• Half-cut cell design: In modern mono-PERC panels, each cell is split in half, which reduces resistive losses and increases power output. This isn’t the same with poly cells.

Shade Performance of Monocrystalline vs Polycrystalline Solar Panels

Shade can significantly reduce the energy output of a solar system. Half-cut cell technology in mono panels allows them to handle shade much better than poly panels.

Let’s check out all the main factors regarding the difference between the shade performance of mono vs poly solar panels.

• Half-cut cell design: Each mono cell is cut into two halves. So, even if one part of the panel is shaded, the other half continues to produce electricity. Poly panels lack this benefit.
• Bypass diodes: Mono panels have advanced bypass diodes that minimize power loss under shaded conditions. On the other hand, poly panels are more likely to suffer from hotspot formation.
• Energy yield in partial shade: In real rooftop conditions, monocrystalline PERC half-cut panels consistently deliver more energy per square meter when trees, buildings, or water tanks shade parts of the roof.

Heat Tolerance and Temperature Co-Efficient of Monocrystalline vs Polycrystalline Solar Panels

Heat tolerance simply indicates how well a panel keeps its power when it gets hot. The temperature coefficient tells you how much power a panel loses for every 1°C rise above 25°C. Needless to say, the lower the temperature coefficient, the better the heat tolerance. 

Since monocrystalline solar panels have a lower temperature coefficient of ~-35% per °C when compared to poly panels that have a higher temperature coefficient of -45% per °C, monocrystalline solar panels perform better under extreme heat. 

Let’s check out all the main factors regarding the difference between the heat tolerance of monocrystalline vs polycrystalline solar panels.

• Hot climate advantage: With lower power loss in heat, mono panels produce more electricity in Indian summers, while poly panels show a sharper drop.
• Higher system ROI: Better heat tolerance directly translates into higher energy generation over 25 years, improving the payback of monocrystalline solar panels compared to polycrystalline solar panels.
• Half-cut design helps indirectly: Half-cut cells reduce current per path, which lowers resistive heating inside the panel. Less internal heating supports better performance as temperatures climb.

Degradation Rate and Lifespan of Mono vs Poly Panels

While both polycrystalline and monocrystalline solar panels from reputable solar panel manufacturers last for 25+ years, the main difference erupts because monocrystalline panels degrade at a much lower rate. It means that at the end of their 25-year life, monocrystalline solar panels will perform at a high efficiency and give more energy output than polycrystalline solar panels.

Let’s check out all the main factors regarding the difference between the degradation rate of monocrystalline vs polycrystalline solar panels.

• Lower annual degradation: Good-quality mono panels from manufacturers like ReNew Solar, Rayzon, and Premier Energies usually lose efficiency by ~0.5% per year, or even less. On the other hand, many poly panels lose ~0.8-1% efficiency per year. Over 25 years, that gap compounds into noticeably higher energy from monocrystalline solar panels.
• Better passivation and PID resistance: Mono PERC cells use rear-side passivation that reduces recombination losses. Many tier-1 mono modules also use anti-PID materials, which help preserve output in humid and high-voltage conditions.
• Financial impact: Slower degradation means monocrystalline panels generate more units of solar electricity over decades, ensuring higher lifetime returns.

Space Efficiency of Mono vs Poly Solar Panels

Space efficiency relates to how many watts of power you can fit per square meter of roof. Because monocrystalline cells are more efficient, they deliver more output from the same panel size. That means fewer panels and less roof area will be required to reach a given system size when compared to polycrystalline solar panels.

Let’s check out all the main factors regarding the difference between the space efficiency of monocrystalline vs polycrystalline solar panels.

• More watts per square meter: Higher cell efficiency in mono panels converts more sunlight within the same footprint. Thus, each square meter of roof yields more output than poly panels.
• Fewer panels for the same kW: You need fewer mono modules to hit a target capacity. Fewer modules also reduce losses from gaps, frames, and cable paths.
• Easier layout on rooftops with limited space: With fewer modules, it’s simpler to work around tanks, vents, and parapets. You can reach your target with fewer rows and less spacing.
• Less hardware and wiring: Fewer modules mean fewer rails, clamps, junctions, and string runs. It leaves more usable roof area and better roof access for solar module cleaning and servicing post installation.
• Room for future expansion: Using less area today leaves space to add capacity later if your consumption grows.

Monocrystalline vs Polycrystalline Solar Panels: Which is the Better Choice for Indian Rooftops?

Monocrystalline solar panels with half-cut PERC cells are a better choice for Indian rooftops. Since these panels are highly efficient, offer a much better return on investment, and have a quicker payback period, they’ve made polycrystalline solar panels almost obsolete in India.

Let’s understand in detail what the main advantages of monocrystalline solar panels are that eventually made poly panels obsolete: 

• They’re great for rooftops with limited space: Higher efficiency means you’ll need fewer panels to reach the desired system capacity that can produce power equivalent to the energy consumption at your home. Hence, mono-PERC half-cut panels are ideal for Indian rooftops with a space crunch.
• They have a quicker payback period: On-grid rooftop solar systems with PERC cells have a payback period of 3-5 years for homes after the customer has availed of a subsidy.
• They produce more energy from the same roof: Higher efficiency means mono-PERC panels with a half-cut design produce more kWh per square meter across the year. Hence, you hit your target capacity with fewer panels.
• They have a stronger performance in heat: Mono-PERC panels have a lower temperature coefficient, so they lose less power on hot days and summers.
• They perform better in partial shade: Half-cut cells and smarter bypass diode layouts in mono panels reduce losses when a corner or a row is shaded by tanks, trees, or parapets.
• They degrade a lot slower than poly panels: Mono panels lose less power each year. So, even after 25 years, they will still deliver noticeably more output than polycrystalline panels.

Cost of Installing On-Grid Rooftop Solar Systems at Homes in India vs the ROI

Installing an on-grid rooftop solar system with bifacial mono-PERC solar panels reduces reliance on grid electricity, which gets expensive by 3-6% every year. As a result, the electricity bills of homeowners get reduced by 90% or more.

Simply stating that on-grid rooftop solar offers a 90% monthly reduction in bills does not show the true impact of the savings you can make by not paying electricity bills. So, we’ve created a simple table that compares the cost of installing a 4 kW on-grid rooftop solar system in India vs the money the system will save for you by generating free solar electricity for 25 years: 

*Please note: The above-mentioned 4 kW solar panel price in India with subsidy is indicative as of 20th September 2025 for the SolarSquare Blue 6ft variant. The actual 4 kW solar plate price depends on your DISCOM charges, city, product variant opted for, panel type, inverter type, mounting structure height, type of after-sales service, savings guarantee, roof height, etc. Prices are subject to change. Additionally, when calculating savings, we have considered an annual tariff escalation of 3% and an annual degradation of 1%. The actual final savings from for a 4 kW solar panel system depends on the types of solar panels you’ve installed and their efficiency, intensity of sunlight your rooftop receives, orientation of the panels and tilt angle, the pollution level and weather conditions in your city, the temperature, shadow on the roof, impact of dirt/dust, and how well you maintain your panels after installation.

Couldn’t find your city and the ideal rooftop solar system size based on your home’s power consumption in the table above? Use SolarSquare’s free solar power calculator to find out the estimated cost of installing a solar system that can fulfill all your home’s energy requirements vs the savings the same system will offer in 25 years in your city. 

But why on-grid solar, you ask? Let’s explain the reasons that make on-grid solar systems better than off-grid and hybrid solar systems:

• They’re cheaper: Both off-grid solar systems and hybrid solar systems use lithium batteries to store excess electricity that the panels generate. These batteries are expensive and also require replacement from time to time. On-grid solar systems do not use batteries for electricity storage. If the panels produce excess power, a bi-directional net meter sends it to the grid. Hence, on-grid systems are cheaper. 
• The government offers a subsidy: You will receive a subsidy under the PM Surya Ghar Muft Bijli Yojana only for installing on-grid rooftop solar systems for housing societies and homes. You can’t claim this assistance if you install off-grid solar systems, ground-mounted solar systems, or commercial rooftop solar systems.

Conclusion

Monocrystalline solar panels with mono-PERC half-cut solar cells are better for residential and commercial installations in India because, unlike poly panels that have a lower efficiency of 16-17%, mono-PERC solar panels reach higher efficiencies of up to 22.5%. This directly translates into higher savings and a quicker payback period for you. 

For any further queries related to solar system installation at home, book a free solar consultation call with SolarSquare today!

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FAQs

Q1. How long do monocrystalline panels last?

Ans. A well-maintained mono panel from top-tier brands can last for 25+ years.

Q2. Which company’s solar panel is best for homes?

Ans. The most reputable solar panel manufacturers in India that you can trust include Rayzon, ReNew Solar, and Premier Energies.

Q3. Which lasts longer, monocrystalline or polycrystalline?

Ans. Both poly and mono panels from reputable brands last for 25+ years. What differs is the fact that the degradation rate of mono panels is lower than that of poly panels. Hence, they produce more output even after 25 years when compared to polycrystalline solar panels.

Q4. Do monocrystalline panels work in shade?

Ans. The latest technology monocrystalline solar panels that use PERC half-cut solar cells work well even in shade.

Q5. What are the disadvantages of polycrystalline solar panels?

Ans. They have a lower efficiency of 16-17% and their performance under shade is poor, too. Moreover, poly panels degrade faster, have a higher temperature coefficient, and their output reduces as the temperature climbs.