Solar Panel Degradation in India: Understanding Efficiency Loss & How Maintenance Prevents It

Solar panels are built to last for 25-30 years, but their performance does not stay constant. Every module undergoes a gradual decline in efficiency year after year. This process is known as solar panel degradation, and it directly affects how much electricity your rooftop solar system generates over time. The most noticeable efficiency drop happens […] The post Solar Panel Degradation in India: Understanding Efficiency Loss & How Maintenance Prevents It appeared first on Rooftop Solar for your home and more | SolarSquare.

Kartavya News

May 12, 2026 - 03:30

Solar panels are built to last for 25-30 years, but their performance does not stay constant. Every module undergoes a gradual decline in efficiency year after year. This process is known as solar panel degradation, and it directly affects how much electricity your rooftop solar system generates over time.

The most noticeable efficiency drop happens in the very first year. Even the most recent high-efficiency solar panels, such as mono-PERC and TOPCon, degrade by 0.7%* to 0.8%* during the 1st year. After the 1st year, the annual solar PV degradation rate becomes 0.5%* to 0.8%* per year.

The massive solar panel degradation during the first year is because even the best solar panels move from a controlled testing environment, known as Standard Test Conditions (STC), into real-world conditions. In the field, they face intense heat, dust, humidity, and continuous exposure to sunlight for the first time, which initiates the natural aging of cells.

The most common causes behind solar panel degradation over time include:

Semiconductor heat build-up: Semiconductor heat build-up: Solar panels use semiconductor cells that allow electric charge to flow. As this current flows, it generates heat. Over time, continuous exposure to heat reduces the panel’s ability to convert solar radiation into electricity.
Material-level wear over time: The internal components of a panel are constantly exposed to sunlight and electrical activity. It leads to slow material degradation, even when the panel is functioning as expected.
Impact of handling and installation: The way solar panels are transported and installed plays a critical role. Rough handling, improper mounting, or stress during installation can create micro-damages that speed up efficiency losses.

Lack of regular cleaning, loose connections, or ignored system issues can worsen the solar panel yearly degradation, resulting in massive performance decline.

Read on to discover the ins and outs of solar panel degradation, including year-on-year PV module degradation rate chart, factors that can increase or decrease the solar panel efficiency degradation, how to increase the lifespan of your solar panels, causes behind the annual degradation of solar panels, difference between light induced degradation of solar panels and solar panel PID, and whether anti-PID solar panels are real or just a marketing gimmick.

TL;DR Summary Box: What is the Impact of Solar Panel Degradation in PV Systems?

The biggest impact of solar cell degradation over time is a reduction in generation. As solar cells in solar panels lose efficiency in converting sunlight into electricity, they produce less and less output.

That being said, you can’t just wish away solar panel efficiency degradation. Every module exposed to real weather conditions outside the lab goes through degradation year after year. However, with proper handling and preventive and corrective maintenance, you can lower photovoltaic degradation rates, but you can’t stop the panel from aging.

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

Main Topics	Key Takeaways
What is solar panel degradation?	Solar panel degradation is the gradual, year-by-year, loss in a panel’s ability to generate electricity due to heat, sunlight exposure, and material aging.
What causes solar panel degradation?	Most critical factors that cause solar panel annual degradation are heat build-up, sunlight exposure, material aging, environmental factors, poor installation, and lack of maintenance.
What is potential-induced degradation of solar cells and panels?	It’s the performance loss caused by voltage differences and poor grounding, leading to leakage currents and reduced output.
What is light-induced degradation of solar panels?	It’s the initial efficiency drop caused by internal cell reactions when panels are first exposed to sunlight.
What is the degradation rate of solar panels in India?*	0.7% to 0.8% in the first year 0.5% to 0.8% per year after the 1st year
What are PID-free solar panels?	There are no solar panels that are completely PID-free. What manufacturers call anti-PID solar panels are modules designed to reduce the impact of Potential Induced Degradation, but they cannot eliminate it entirely.
How to reduce PID in solar panels?	It can be reduced through proper earthing, strong DC grounding, and regular system maintenance.
How to increase the lifespan of your solar panels despite solar panel degradation being unavoidable?	Ensure proper installation, regular cleaning, strong earthing, quality components, and ongoing performance monitoring.

What is Solar Panel Degradation?

Solar panel degradation is the gradual reduction in a panel’s ability to convert sunlight into solar electricity over time. Every type of solar panel goes through degradation year after year.

As solar cells are exposed to real-world conditions such as heat, sunlight, and electrical load, their internal materials begin to wear and tear. It leads to a slow but steady decline in efficiency and power output.

Here are the key factors that result in degradation of PV modules:

Continuous heat generation within cells
Exposure to sunlight and UV radiation
Material aging under electrical stress
Environmental impact due to dust, humidity, and temperature
Handling and installation-related micro-damage
Long-term operational wear and tear

Although it can’t be eliminated, solar panel degradation can certainly be lowered through proper maintenance and handling.

Degradation Factor of Solar Panels vs Derating Factor of Solar Panels: Are They the Same?

These two terms are often confused, but they refer to very different aspects of a rooftop solar panel system for homes.

Solar panel degradation is related to the panels themselves: It represents the gradual loss of their ability to generate electricity as they age, driven by material and environmental factors.
Derating factor of solar panels: Derating is linked to the solar inverter. It occurs when the inverter is unable to convert the full input power from the panels into usable output. This usually happens due to inverter overloading. A conversion loss of around 1.5% to 2% is considered normal, while in higher-capacity inverters, it can increase to 3% to 4%.

In simple terms, PV module degradation rate reduces how much power the panels can produce, while derating factor of solar panels affects how much of that produced power is actually converted and delivered.

What Causes Solar Panel Degradation?

Annual degradation of solar panels occurs due to internal material behavior and external operating conditions. Once panels are installed in the real environment outside the labs, they are exposed to heat, sunlight, electrical stress, and installation-related factors that gradually reduce their efficiency.

Some of these causes are natural and unavoidable, while others depend on how well the system is handled and maintained.

Here are the key factors that contribute to solar panel yearly degradation:

First-time exposure to sunlight and other environmental factors: PV panels are tested under Standard Test Conditions in a controlled lab environment. Once installed outdoors, exposure to real weather conditions such as heat, dust, and humidity initiates the degradation process, especially in the first year.
Thermal stress from electrical flow: Semiconductor cells allow electric current to pass through them, which generates heat. Continuous heating over long periods degrades the cell structure and reduces solar panel efficiency.
Light-induced degradation (LID): Initial exposure to sunlight causes a performance drop due to material-level reactions within the cells. This varies based on the type of module and materials used.
Potential-induced degradation (PID in solar panels): Voltage differences within the module, especially when charge is not properly grounded after sunset, can lead to leakage currents and performance loss over time.
Material aging and electrical stress: Constant exposure to sunlight and electrical load can cause slow degradation of internal materials, even under normal operating conditions.
Poor handling and installation practices: Rough transportation, improper panel mounting, or stress during installation and maintenance can cause micro-damage to cells, accelerating solar panel degradation over time.
Environmental conditions: High temperatures, humidity, dust accumulation, and pollution levels can further impact the rate of efficiency loss.
Inadequate maintenance practices: Lack of professional solar panel cleaning, loose connections, or delayed issue detection can worsen performance decline and increase photovoltaic degradation rates over time.

What is the Degradation Rate of Solar Panels in India?

The solar panel degradation rate during the first year of solar installation is 0.7%* to 0.8%*. It’s so high because the panel is exposed to real-world conditions for the first time. After the 1st year, the drop in efficiency ranges from 0.5%* to 0.8%* per year.

What is Potential-Induced Degradation of Solar Cells and Panels?

Potential-Induced Degradation (PID), also known as PID, is a performance loss caused by voltage differences within the solar module. After sunset, if the electrical charge in the modules is not properly grounded, it can lead to leakage currents. Over time, this results in a reduction in power output and overall panel efficiency.

What is Light-Induced Degradation of Solar Panels?

Light-Induced Degradation, or LID, refers to the initial drop in performance that occurs when solar panels are first exposed to sunlight within the first few hours to days of operation.

Solar Panel Degradation Curve: What Happens in the 1st, 10th, and 25th Years?

The solar panel degradation curve is highly predictable, with the highest drop in efficiency occurring in the first year, followed by a slower, more stable decline over the remaining lifespan.

After the massive drop during the 1st year, the add-on every year ranges between 0.5% to 0.5%.

Here’s what solar panel degradation looks like:

Solar panel degradation during the first year*: 0.7% to 0.8%
Solar panel degradation during the 10th year*: 5.2% to 8%.
Solar panel degradation during the 25th year*: 12.7% to 20%

Solar Panel Degradation Chart: Year-by-Year Solar Panel Degradation Rate Comparison

Based on the fact that, after year 1, the annual degradation of solar panels adds 0.5% to 0.8% in losses, we’ve created this estimated solar panel degradation chart.

Year	Solar Panel Annual Degradation*	Cumulative Degradation*	Remaining Efficiency
1	0.7% – 0.8%	0.7% – 0.8%	99.2% – 99.3%
2	0.5% – 0.8%	1.2% – 1.6%	98.4% – 98.8%
3	0.5% – 0.8%	1.7% – 2.4%	97.6% – 98.3%
4	0.5% – 0.8%	2.2% – 3.2%	96.8% – 97.8%
5	0.5% – 0.8%	2.7% – 4%	96% – 97.3%
6	0.5% – 0.8%	3.2% – 4.8%	95.2% – 96.8%
7	0.5% – 0.8%	3.7% – 5.6%	94.4% – 96.3%
8	0.5% – 0.8%	4.2% – 6.4%	93.6% – 95.8%
9	0.5% – 0.8%	4.7% – 7.2%	92.8% – 95.3%
10	0.5% – 0.8%	5.2% – 8%	92% – 94.8%
11	0.5% – 0.8%	5.7% – 8.8%	91.2% – 94.3%
12	0.5% – 0.8%	6.2% – 9.6%	90.4% – 93.8%
13	0.5% – 0.8%	6.7% – 10.4%	89.6% – 93.3%
14	0.5% – 0.8%	7.2% – 11.2%	88.8% – 92.8%
15	0.5% – 0.8%	7.7% – 12%	88% – 92.3%
16	0.5% – 0.8%	8.2% – 12.8%	87.2% – 91.8%
17	0.5% – 0.8%	8.7% – 13.6%	86.4% – 91.3%
18	0.5% – 0.8%	9.2% – 14.4%	85.6% – 90.8%
19	0.5% – 0.8%	9.7% – 15.2%	84.8% – 90.3%
20	0.5% – 0.8%	10.2% – 16.0%	84% – 89.8%
21	0.5% – 0.8%	10.7% – 16.8%	83.2% – 89.3%
22	0.5% – 0.8%	11.2% – 17.6%	82.4% – 88.8%
23	0.5% – 0.8%	11.7% – 18.4%	81.6% – 88.3%
24	0.5% – 0.8%	12.2% – 19.2%	80.8% – 87.8%
25	0.5% – 0.8%	12.7% – 20%	80% – 87.3%

Why is it Important to Consider Solar Panel Annual Degradation Rates While Buying a Module for Your Home?

Investing in rooftop solar is a lifelong commitment. It’s supposed to lower your electricity bills by 90% or more for 25-30 years. And since the solar panel degradation rate directly determines how much electricity your solar system will produce over its lifetime, it impacts your savings, payback period, and long-term return on investment.

A lower solar panel annual degradation rate means your panels will maintain higher efficiency for longer, resulting in more consistent energy generation year after year.

Here’s why photovoltaic degradation rates should be a key factor in your decision:

Direct impact on lifetime generation: Panels with lower degradation produce more electricity over 25 years, resulting in lower bills and higher solar savings.
Affects the system payback period: Faster degradation can delay the time to recover your initial investment.
Reflects module quality and technology: Advanced technologies like TOPCon and high-quality Mono-PERC modules exhibit more stable degradation behavior than older polycrystalline panels.
Helps set realistic performance expectations: Understanding solar panel degradation prevents overestimating future output based on first-year performance.

Normal Annual Degradation of Solar Panels vs Preventable Performance Loss

Not all performance loss in a solar system is due to panel degradation. While some solar panel degradation per year is natural and unavoidable, a portion of the loss is preventable and depends on how well the system is designed, installed, and maintained.

Let’s understand both:

Natural solar panel degradation per year: This is the unavoidable decline in efficiency that occurs as solar panels age. It’s a result of heat generation within semiconductor cells, prolonged exposure to sunlight, material aging under electrical stress, and real-world conditions such as temperature, dust, and humidity.
Preventable performance loss in solar systems: This refers to efficiency losses caused by system design, poor installation quality, and maintenance gaps. For example, wiring and cable losses can reduce output if not properly designed or maintained. Poor execution during installation, loose connections, or lack of regular maintenance can further increase these losses. The good news is that all these losses can be prevented through proper system design, high-quality solar installation, regular maintenance, and ongoing performance diagnostics.

What are Anti-PID Solar Panels?

An anti-PID module marketed to have PID-free solar cells is either a marketing gimmick or a miscommunication. No solar panel can be 100% free from Potential Induced Degradation, as PID is influenced not only by module design but also by system voltage, grounding quality, and operating conditions over time.

What solar panel manufacturers actually mean by anti-PID is that the module is designed to be more resistant to PID. This is achieved through improvements in materials, cell structure, and protective layers that reduce the likelihood and severity of leakage currents.

In simple terms, anti-PID panels can reduce the impact of PID but cannot eliminate it.

How to Reduce PID in Solar Panels?

While PID in solar panels cannot be fully avoided, proper system design, handling, and maintenance can significantly reduce its impact.

Let’s find out all the practices that can lower PID damage in solar panels:

Regular system maintenance: Routine checks help ensure the system operates within safe electrical limits and reduce the chances of PID-related issues.
Module-to-module earthing: Proper earthing between panels prevents unwanted voltage differences from building up across modules.
High-quality DC-side earthing: The system’s DC earthing should be properly implemented. If grounding is weak, PID effects can increase over time.

Signs Your Solar Panels Are Degrading Faster Than Normal

Certain signs, like a drop in solar generation and cell discoloration, are tell-tale signs that your panels might be degrading faster than normal. Identifying them early can help you take corrective action and avoid long-term performance loss.

Here are the most critical indicators to watch for:

Noticeable drop in power generation: If your system is producing significantly less electricity than expected for your location for that particular season, it could indicate accelerated performance decline.
Uneven output across panels: When some panels generate less power than others in the same system, it may point to localized degradation or damage.
Visible cell discoloration: Changes in cell color can signal internal issues. In Mono-PERC panels, for example, degraded cells appear darker compared to surrounding cells.
Frequent system performance fluctuations: Inconsistent output without clear external reasons such as weather changes may indicate degradation.
Hotspots or localized heating: Certain areas of the panel heating more than others can be a sign of cell damage or electrical faults, which can accelerate solar panel degradation.

How to Increase the Lifespan of Your Solar Panels?

The actual lifespan and performance of solar panels depend heavily on how well the system is maintained and installed. While solar panel degradation cannot be stopped, the rate at which it happens can be controlled to a large extent with the right practices.

Here are the most effective ways to increase the lifespan of your solar panels:

Professional cleaning and maintenance: Regular cleaning removes dust, dirt, and bird droppings that block sunlight and increase thermal stress. Periodic professional inspections also help identify early signs of faults in wiring and inverter before they impact performance.
High-quality installation: If panels are installed properly with correct mounting and tight connections, you avoid unnecessary stress and damage during setup.
Strong earthing and electrical design: Proper DC and AC earthing, along with correct system voltage design, reduces long-term electrical stress on the panels.
Use of high-quality components: Choosing reliable modules, cables, connectors, and inverters ensures the system operates efficiently without added stress from substandard solar components.
Regular performance monitoring: Tracking system output helps detect unusual drops in generation early. This allows you to identify whether the issue is solar PV degradation or a fixable system fault.
Timely preventive and corrective maintenance: Addressing issues like loose wiring, connector faults, or inverter inefficiencies early can prevent additional stress on the panels.
Avoiding physical damage and stress: Ensuring panels are not subjected to unnecessary load, shading issues, or physical impact during handling helps maintain their structural and electrical integrity over time.

How Can Assure by SolarSquare Help Prevent Efficiency Loss in Solar Systems?

Assure by SolarSquare provides professional solar panel cleaning, maintenance, and inspection services for homeowners who may not have ongoing support from their original installer. With operations in cities such as Bhopal, Nagpur, Delhi, and Lucknow (and expanding across India), Assure has already supported 1,000+ customers.

Here’s a list of our Preventive Maintenance (PM) services that help improve your system’s performance and reliability:

Warranty-safe panel cleaning: Our trained technicians clean your panels using only manufacturer-approved methods. Soft-bristle equipment protects the anti-reflective coating and glass. Every visit includes documentation of before-and-after photos and compliance logs. As a result, your warranty stays intact if you ever need to raise a claim.
Automated maintenance schedule: We build a cleaning and maintenance calendar around your specific site conditions, dust load, and system size. You get WhatsApp, SMS, and email reminders before every visit. Your full service history, including technician notes, is available for download at any time.
Performance diagnostics and reporting: We compare your system’s actual power generation with the expected output and review your inverter data. If we detect any drop in performance, we identify the cause and provide you with a clear action plan to recover lost power.
Electrical and safety check: Trained technicians inspect the wiring, earthing, connectors, and safety devices in your system. They fix loose connections and overheating points on the spot. Each visit also includes checks for DC and AC cables, MCBs and surge protectors, proper tightening of terminals, and seals that keep moisture out.
Thermal health scan: We use an infrared camera to scan your solar panels and detect issues like hotspots, faulty cells, or shading that you cannot see with the naked eye. Each problem is identified for the exact panel and shared with you as clear images along with a simple list of what needs attention first.

Assure also provides Corrective Maintenance (CM) services when your solar system needs emergency repairs.

Problem identification: If a panel cracks, the inverter fails, wiring gets damaged, or a protection device stops working, our trained technicians diagnose the issue and clearly explain what went wrong.
Best fix recommendation: Our team helps you understand the best course of action before arranging the required parts and repairs.
Repair or replacement services: Once approved, the team fixes the problem and restores your system’s performance.

Conclusion

Solar panel degradation is a natural process that affects all solar panels over time. The highest drop occurs in the first year, around 0.7%* to 0.8%*, as the panels are exposed to real-world conditions for the first time. After the first year, the degradation rate stabilizes and continues at around 0.5%* to 0.8%* per year.

While degradation cannot be eliminated, its impact can be reduced through proper maintenance and strong installation practices. Measures such as regular system checks, correct wiring, and proper earthing help minimize losses like PID and ensure consistent performance. For any further queries related to solar panel maintenance or increasing output, you can get in touch with Assure’s team for free.

If you’re looking to install rooftop solar at your home, you can book a free solar consultation call with SolarSquare. It’s a no-obligation call, meaning you don’t have to buy from us. You buy only if you are convinced.

FAQs

What happens to solar panels after 25-30 years?

While solar panels continue to operate at around 80% efficiency even after 25 years, they are often replaced at the end of their lifespan. They are not immediately useless, but their output is lower than that of newer, more efficient panels.

Which factors increase the degradation of solar panels over time?

Here are the most critical factors that can accelerate solar panel yearly degradation:

High temperatures and thermal stress
Dust, pollution, and humidity
Poor installation and rough handling
Weak earthing and PID
Lack of regular maintenance
Low-quality modules and components

Which factors decrease solar cell degradation over time?

Here are the most critical factors that decrease solar cell degradation over time:

Proper installation and system design
Strong DC and module earthing
Regular cleaning and maintenance
Use of high-quality panels and components
Performance monitoring and timely issue detection

Is it worth replacing 10-year-old solar panels?

Not really. Solar panels are designed to last for 25-30 years. At year 10, their efficiency is still very high. So, replacing them is not relevant unless you installed low-grade modules that are no longer generating the expected output.

Can maintenance prevent degradation of PV modules?

No. Solar panel degradation is a natural process and cannot be prevented. However, proper maintenance can reduce the degradation rate and lower additional performance losses, helping the system operate closer to its expected efficiency.

Is solar panel degradation calculation at home possible?

No. Accurate solar panel degradation calculation requires long-term performance data, system diagnostics, and technical analysis. It cannot be reliably done at home without proper tools and expertise.

Why do solar panels lose efficiency over time?

Solar panels lose efficiency due to continuous exposure to sunlight, heat, dirt and dust buildup, internal cell defects, and electrical stress. Over time, this causes material aging within the solar cells, leading to a gradual decline in their ability to convert sunlight into electricity.

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

Main Topics Key Takeaways What is solar panel degradation? Solar panel degradation is the gradual, year-by-year, loss in a panel’s ability to generate electricity due to heat, sunlight exposure, and material aging. What causes solar panel degradation? Most critical factors that cause solar panel annual degradation are heat build-up, sunlight exposure, material aging, environmental factors, poor installation, and lack of maintenance. What is potential-induced degradation of solar cells and panels? It’s the performance loss caused by voltage differences and poor grounding, leading to leakage currents and reduced output. What is light-induced degradation of solar panels? It's the initial efficiency drop caused by internal cell reactions when panels are first exposed to sunlight. What is the degradation rate of solar panels in India?* 0.7% to 0.8% in the first year 0.5% to 0.8% per year after the 1st year

What are PID-free solar panels? There are no solar panels that are completely PID-free. What manufacturers call anti-PID solar panels are modules designed to reduce the impact of Potential Induced Degradation, but they cannot eliminate it entirely. How to reduce PID in solar panels? It can be reduced through proper earthing, strong DC grounding, and regular system maintenance. How to increase the lifespan of your solar panels despite solar panel degradation being unavoidable? Ensure proper installation, regular cleaning, strong earthing, quality components, and ongoing performance monitoring.

Here are the key factors that result in degradation of PV modules:

Continuous heat generation within cells Exposure to sunlight and UV radiation Material aging under electrical stress Environmental impact due to dust, humidity, and temperature Handling and installation-related micro-damage Long-term operational wear and tear

Although it can’t be eliminated, solar panel degradation can certainly be lowered through proper maintenance and handling." } },{ "@type": "Question", "name": "What Causes Solar Panel Degradation?", "acceptedAnswer": { "@type": "Answer", "text": "Annual degradation of solar panels occurs due to internal material behavior and external operating conditions. Once panels are installed in the real environment outside the labs, they are exposed to heat, sunlight, electrical stress, and installation-related factors that gradually reduce their efficiency.

Some of these causes are natural and unavoidable, while others depend on how well the system is handled and maintained.

Here are the key factors that contribute to solar panel yearly degradation:

First-time exposure to sunlight and other environmental factors: PV panels are tested under Standard Test Conditions in a controlled lab environment. Once installed outdoors, exposure to real weather conditions such as heat, dust, and humidity initiates the degradation process, especially in the first year. Thermal stress from electrical flow: Semiconductor cells allow electric current to pass through them, which generates heat. Continuous heating over long periods degrades the cell structure and reduces solar panel efficiency. Light-induced degradation (LID): Initial exposure to sunlight causes a performance drop due to material-level reactions within the cells. This varies based on the type of module and materials used. Potential-induced degradation (PID in solar panels): Voltage differences within the module, especially when charge is not properly grounded after sunset, can lead to leakage currents and performance loss over time. Material aging and electrical stress: Constant exposure to sunlight and electrical load can cause slow degradation of internal materials, even under normal operating conditions. Poor handling and installation practices: Rough transportation, improper panel mounting, or stress during installation and maintenance can cause micro-damage to cells, accelerating solar panel degradation over time. Environmental conditions: High temperatures, humidity, dust accumulation, and pollution levels can further impact the rate of efficiency loss. Inadequate maintenance practices: Lack of professional solar panel cleaning, loose connections, or delayed issue detection can worsen performance decline and increase photovoltaic degradation rates over time." } },{ "@type": "Question", "name": "What is the Degradation Rate of Solar Panels in India?", "acceptedAnswer": { "@type": "Answer", "text": "The solar panel degradation rate during the first year of solar installation is 0.7%* to 0.8%*. It's so high because the panel is exposed to real-world conditions for the first time. After the 1st year, the drop in efficiency ranges from 0.5%* to 0.8%* per year.

*Please note: Based on internal case studies at SolarSquare, the above-mentioned solar panel degradation factor values are indicative and vary across installations depending on module type, manufacturing quality, environmental conditions, and system execution. Factors such as temperature, dust levels, humidity, handling during transportation, installation practices, and ongoing maintenance significantly influence the solar panel efficiency degradation rate. These ranges are not fixed for every module, as actual solar panel degradation differs based on project-specific conditions and long-term operational factors." } },{ "@type": "Question", "name": "What is Potential-Induced Degradation of Solar Cells and Panels?", "acceptedAnswer": { "@type": "Answer", "text": "Potential-Induced Degradation (PID), also known as PID, is a performance loss caused by voltage differences within the solar module. After sunset, if the electrical charge in the modules is not properly grounded, it can lead to leakage currents. Over time, this results in a reduction in power output and overall panel efficiency." } },{ "@type": "Question", "name": "What is Light-Induced Degradation of Solar Panels?", "acceptedAnswer": { "@type": "Answer", "text": "Light-Induced Degradation, or LID, refers to the initial drop in performance that occurs when solar panels are first exposed to sunlight within the first few hours to days of operation.

It happens due to internal reactions within the silicon cells, where defects form and trap charge carriers, reducing the panel’s efficiency. The extent of this loss depends on the type of module and the materials used in manufacturing. That’s why different solar cell technologies show varying levels of LID." } },{ "@type": "Question", "name": "Solar Panel Degradation Curve: What Happens in the 1st, 10th, and 25th Years?", "acceptedAnswer": { "@type": "Answer", "text": "The solar panel degradation curve is highly predictable, with the highest drop in efficiency occurring in the first year, followed by a slower, more stable decline over the remaining lifespan.

After the massive drop during the 1st year, the add-on every year ranges between 0.5% to 0.5%.

Here’s what solar panel degradation looks like:

Solar panel degradation during the first year*: 0.7% to 0.8% Solar panel degradation during the 10th year*: 5.2% to 8%. Solar panel degradation during the 25th year*: 12.7% to 20%

Solar Panel Degradation Chart: Year-by-Year Solar Panel Degradation Rate Comparison

Based on the fact that, after year 1, the annual degradation of solar panels adds 0.5% to 0.8% in losses, we've created this estimated solar panel degradation chart.

Year Solar Panel Annual Degradation* Cumulative Degradation* Remaining Efficiency 1 0.7% – 0.8% 0.7% – 0.8% 99.2% – 99.3% 2 0.5% – 0.8% 1.2% – 1.6% 98.4% – 98.8% 3 0.5% – 0.8% 1.7% – 2.4% 97.6% – 98.3% 4 0.5% – 0.8% 2.2% – 3.2% 96.8% – 97.8% 5 0.5% – 0.8% 2.7% – 4% 96% – 97.3% 6 0.5% – 0.8% 3.2% – 4.8% 95.2% – 96.8% 7 0.5% – 0.8% 3.7% – 5.6% 94.4% – 96.3% 8 0.5% – 0.8% 4.2% – 6.4% 93.6% – 95.8% 9 0.5% – 0.8% 4.7% – 7.2% 92.8% – 95.3% 10 0.5% – 0.8% 5.2% – 8% 92% – 94.8% 11 0.5% – 0.8% 5.7% – 8.8% 91.2% – 94.3% 12 0.5% – 0.8% 6.2% – 9.6% 90.4% – 93.8% 13 0.5% – 0.8% 6.7% – 10.4% 89.6% – 93.3% 14 0.5% – 0.8% 7.2% – 11.2% 88.8% – 92.8% 15 0.5% – 0.8% 7.7% – 12% 88% – 92.3% 16 0.5% – 0.8% 8.2% – 12.8% 87.2% – 91.8% 17 0.5% – 0.8% 8.7% – 13.6% 86.4% – 91.3% 18 0.5% – 0.8% 9.2% – 14.4% 85.6% – 90.8% 19 0.5% – 0.8% 9.7% – 15.2% 84.8% – 90.3% 20 0.5% – 0.8% 10.2% – 16.0% 84% – 89.8% 21 0.5% – 0.8% 10.7% – 16.8% 83.2% – 89.3% 22 0.5% – 0.8% 11.2% – 17.6% 82.4% – 88.8% 23 0.5% – 0.8% 11.7% – 18.4% 81.6% – 88.3% 24 0.5% – 0.8% 12.2% – 19.2% 80.8% – 87.8% 25 0.5% – 0.8% 12.7% – 20% 80% – 87.3%

*DISCLAIMER: Based on internal case studies at SolarSquare, the above-mentioned solar panel degradation factor values are indicative and vary across installations depending on module type, manufacturing quality, environmental conditions, and system execution. Factors such as temperature, dust levels, humidity, handling during transportation, installation practices, and ongoing maintenance significantly influence the solar panel efficiency degradation rate. These ranges are not fixed for every module, as actual solar panel degradation differs based on project-specific conditions and long-term operational factors." } },{ "@type": "Question", "name": "Why is it Important to Consider Solar Panel Annual Degradation Rates While Buying a Module for Your Home?", "acceptedAnswer": { "@type": "Answer", "text": "Investing in rooftop solar is a lifelong commitment. It’s supposed to lower your electricity bills by 90% or more for 25-30 years. And since the solar panel degradation rate directly determines how much electricity your solar system will produce over its lifetime, it impacts your savings, payback period, and long-term return on investment.

A lower solar panel annual degradation rate means your panels will maintain higher efficiency for longer, resulting in more consistent energy generation year after year.

Here’s why photovoltaic degradation rates should be a key factor in your decision:

Direct impact on lifetime generation: Panels with lower degradation produce more electricity over 25 years, resulting in lower bills and higher solar savings. Affects the system payback period: Faster degradation can delay the time to recover your initial investment. Reflects module quality and technology: Advanced technologies like TOPCon and high-quality Mono-PERC modules exhibit more stable degradation behavior than older polycrystalline panels. Helps set realistic performance expectations: Understanding solar panel degradation prevents overestimating future output based on first-year performance." } },{ "@type": "Question", "name": "What are Anti-PID Solar Panels?", "acceptedAnswer": { "@type": "Answer", "text": "An anti-PID module marketed to have PID-free solar cells is either a marketing gimmick or a miscommunication. No solar panel can be 100% free from Potential Induced Degradation, as PID is influenced not only by module design but also by system voltage, grounding quality, and operating conditions over time.

What solar panel manufacturers actually mean by anti-PID is that the module is designed to be more resistant to PID. This is achieved through improvements in materials, cell structure, and protective layers that reduce the likelihood and severity of leakage currents.

In simple terms, anti-PID panels can reduce the impact of PID but cannot eliminate it." } },{ "@type": "Question", "name": "How to Reduce PID in Solar Panels?", "acceptedAnswer": { "@type": "Answer", "text": "While PID in solar panels cannot be fully avoided, proper system design, handling, and maintenance can significantly reduce its impact.

Let's find out all the practices that can lower PID damage in solar panels:

Regular system maintenance: Routine checks help ensure the system operates within safe electrical limits and reduce the chances of PID-related issues. Module-to-module earthing: Proper earthing between panels prevents unwanted voltage differences from building up across modules. High-quality DC-side earthing: The system's DC earthing should be properly implemented. If grounding is weak, PID effects can increase over time." } },{ "@type": "Question", "name": "How to Increase the Lifespan of Your Solar Panels?", "acceptedAnswer": { "@type": "Answer", "text": "The actual lifespan and performance of solar panels depend heavily on how well the system is maintained and installed. While solar panel degradation cannot be stopped, the rate at which it happens can be controlled to a large extent with the right practices.

Here are the most effective ways to increase the lifespan of your solar panels:

Professional cleaning and maintenance: Regular cleaning removes dust, dirt, and bird droppings that block sunlight and increase thermal stress. Periodic professional inspections also help identify early signs of faults in wiring and inverter before they impact performance. High-quality installation: If panels are installed properly with correct mounting and tight connections, you avoid unnecessary stress and damage during setup. Strong earthing and electrical design: Proper DC and AC earthing, along with correct system voltage design, reduces long-term electrical stress on the panels. Use of high-quality components: Choosing reliable modules, cables, connectors, and inverters ensures the system operates efficiently without added stress from substandard solar components. Regular performance monitoring: Tracking system output helps detect unusual drops in generation early. This allows you to identify whether the issue is solar PV degradation or a fixable system fault. Timely preventive and corrective maintenance: Addressing issues like loose wiring, connector faults, or inverter inefficiencies early can prevent additional stress on the panels. Avoiding physical damage and stress: Ensuring panels are not subjected to unnecessary load, shading issues, or physical impact during handling helps maintain their structural and electrical integrity over time." } },{ "@type": "Question", "name": "How Can Assure by SolarSquare Help Prevent Efficiency Loss in Solar Systems?", "acceptedAnswer": { "@type": "Answer", "text": "Assure by SolarSquare provides professional solar panel cleaning, maintenance, and inspection services for homeowners who may not have ongoing support from their original installer. With operations in cities such as Bhopal, Nagpur, Delhi, and Lucknow (and expanding across India), Assure has already supported 1,000+ customers.

Here’s a list of our Preventive Maintenance (PM) services that help improve your system’s performance and reliability:

Warranty-safe panel cleaning: Our trained technicians clean your panels using only manufacturer-approved methods. Soft-bristle equipment protects the anti-reflective coating and glass. Every visit includes documentation of before-and-after photos and compliance logs. As a result, your warranty stays intact if you ever need to raise a claim. Automated maintenance schedule: We build a cleaning and maintenance calendar around your specific site conditions, dust load, and system size. You get WhatsApp, SMS, and email reminders before every visit. Your full service history, including technician notes, is available for download at any time. Performance diagnostics and reporting: We compare your system's actual power generation with the expected output and review your inverter data. If we detect any drop in performance, we identify the cause and provide you with a clear action plan to recover lost power. Electrical and safety check: Trained technicians inspect the wiring, earthing, connectors, and safety devices in your system. They fix loose connections and overheating points on the spot. Each visit also includes checks for DC and AC cables, MCBs and surge protectors, proper tightening of terminals, and seals that keep moisture out. Thermal health scan: We use an infrared camera to scan your solar panels and detect issues like hotspots, faulty cells, or shading that you cannot see with the naked eye. Each problem is identified for the exact panel and shared with you as clear images along with a simple list of what needs attention first.

Assure also provides Corrective Maintenance (CM) services when your solar system needs emergency repairs.

Problem identification: If a panel cracks, the inverter fails, wiring gets damaged, or a protection device stops working, our trained technicians diagnose the issue and clearly explain what went wrong. Best fix recommendation: Our team helps you understand the best course of action before arranging the required parts and repairs. Repair or replacement services: Once approved, the team fixes the problem and restores your system’s performance." } },{ "@type": "Question", "name": "What happens to solar panels after 25-30 years?", "acceptedAnswer": { "@type": "Answer", "text": "While solar panels continue to operate at around 80% efficiency even after 25 years, they are often replaced at the end of their lifespan. They are not immediately useless, but their output is lower than that of newer, more efficient panels.

Another important reason for replacement is the warranty. Most solar panels come with a 25-year performance warranty, after which coverage ends. By upgrading to new panels, you get fresh warranty coverage, ensuring long-term reliability and peace of mind." } },{ "@type": "Question", "name": "Which factors increase the degradation of solar panels over time?", "acceptedAnswer": { "@type": "Answer", "text": "Here are the most critical factors that can accelerate solar panel yearly degradation:

High temperatures and thermal stress Dust, pollution, and humidity Poor installation and rough handling Weak earthing and PID Lack of regular maintenance Low-quality modules and components" } },{ "@type": "Question", "name": "Which factors decrease solar cell degradation over time?", "acceptedAnswer": { "@type": "Answer", "text": "Here are the most critical factors that decrease solar cell degradation over time:

Proper installation and system design Strong DC and module earthing Regular cleaning and maintenance Use of high-quality panels and components Performance monitoring and timely issue detection" } },{ "@type": "Question", "name": "Is it worth replacing 10-year-old solar panels?", "acceptedAnswer": { "@type": "Answer", "text": "Not really. Solar panels are designed to last for 25-30 years. At year 10, their efficiency is still very high. So, replacing them is not relevant unless you installed low-grade modules that are no longer generating the expected output." } },{ "@type": "Question", "name": "Can maintenance prevent degradation of PV modules?", "acceptedAnswer": { "@type": "Answer", "text": "No. Solar panel degradation is a natural process and cannot be prevented. However, proper maintenance can reduce the degradation rate and lower additional performance losses, helping the system operate closer to its expected efficiency." } },{ "@type": "Question", "name": "Is solar panel degradation calculation at home possible?", "acceptedAnswer": { "@type": "Answer", "text": "No. Accurate solar panel degradation calculation requires long-term performance data, system diagnostics, and technical analysis. It cannot be reliably done at home without proper tools and expertise." } },{ "@type": "Question", "name": "Why do solar panels lose efficiency over time?", "acceptedAnswer": { "@type": "Answer", "text": "Solar panels lose efficiency due to continuous exposure to sunlight, heat, dirt and dust buildup, internal cell defects, and electrical stress. Over time, this causes material aging within the solar cells, leading to a gradual decline in their ability to convert sunlight into electricity." } }] }

The post Solar Panel Degradation in India: Understanding Efficiency Loss & How Maintenance Prevents It appeared first on Rooftop Solar for your home and more | SolarSquare.