If you’re considering installing solar panels, it’s important to understand how their efficiency holds up over time. After five years, you might wonder how much energy your system will still produce and how panel performance changes with age.
Solar panel efficiency directly impacts the value and effectiveness of your investment. While some decline in performance is normal, high-quality panels and proper installation can help maintain strong energy production and extend the system’s lifespan.
In this article, we’ll explore how efficient solar panels are after five years and what factors influence their long-term performance.
Key Takeaways
- Most solar panels lose about 0.5% to 0.8% efficiency annually, operating at roughly 96–97.5% capacity after five years.
- Environmental factors like temperature, humidity, and UV exposure significantly impact solar panel degradation and efficiency over time.
- Regular cleaning and system monitoring are essential to maintaining optimal panel performance and extending lifespan.
- Choosing high-efficiency panels with durable materials maximizes energy production and long-term reliability.
Solar Panel Efficiency
Most modern solar panels are designed to last 25 to 30 years or more. While they don't stop working after this period, their energy output gradually declines due to natural wear and exposure to the elements. This decline is known as degradation.
Solar panels lose about 0.5%-0.8% of their efficiency each year. After 25 years, a typical panel still produces around 85–90% of its original output. However, this rate can vary depending on the quality of the panel and the environmental conditions in which it operates. Panels exposed to extreme heat, high humidity, or prolonged UV radiation may degrade more quickly than those in milder climates.
Even with gradual efficiency loss, a well-made solar panel system remains a reliable and cost-effective energy source over the long term.
What to Expect from Solar Panels After 5 Years
With an average degradation rate of 0.5% to 0.8% per year, solar panels typically experience a total efficiency loss of about 2.5% to 4% after five years. This means that most systems will still be operating at approximately 96% to 97.5% of their original capacity.
This minimal decline is typical for high-quality panels from reputable manufacturers and assumes proper installation and maintenance—both of which are key when installing solar panels in Hastings-on-Hudson. Well-maintained solar panels continue to perform efficiently after five years and will typically provide strong, consistent energy production for decades to come.
Factors That Influence Solar Panel Degradation
Several environmental and material-related conditions can contribute to the gradual decline in solar panel performance. Knowing what to watch for allows you to choose equipment that’s better suited to your specific climate and installation environment. Key factors that influence solar panel degradation include the following:
Temperature
Excessive heat can negatively affect the materials within a solar panel, leading to faster degradation. High temperatures may also reduce voltage output and limit the overall lifespan of the system.
Solar panels perform optimally in moderate temperatures up to 77°F (25°C). Generally, a panel’s efficiency decreases as temperatures rise above this threshold. Specifically, a panel’s output power will decline by approximately 0.5% for every degree Fahrenheit (or about 0.32% per degree Celsius) above 77°F.
In New York, summer temperatures commonly range from around 70°F (21°C) to 85°F (29°C) in August, with occasional spikes above 90°F (32°C). These elevated temperatures can lead to noticeable reductions in energy production during hotter days.
Humidity
High levels of humidity can lead to moisture ingress, especially in poorly sealed panels. This moisture can damage electrical connections and weaken internal components, resulting in reduced efficiency over time.
In New York, the average annual relative humidity is 58.3%. The state can experience highs of 70–75% during the summer. This humid environment during warmer months can accelerate panel degradation if proper protective measures are not in place.
For example, a study on photovoltaic panel performance found that an increase of 42.07% in relative humidity can lead to a degradation of panel output by up to 28.77%. This highlights the importance of proper sealing and protective measures to maintain efficiency in humid environments.
UV Exposure
Continuous exposure to ultraviolet (UV) radiation can degrade the protective layers and materials of a solar panel. Excessive UV exposure gradually diminishes panel efficiency and can potentially damage the protective coatings that safeguard solar cells.
The degree of UV-related degradation varies depending on the quality and type of solar panel materials used. Studies have calculated average degradation rates around 0.12% per year due to UV exposure, with maximum rates reaching up to 0.73% per year in extreme conditions.
While UV exposure tends to be more impactful in regions with high solar irradiance, it remains an important factor to consider even in moderate climates like New York, as prolonged exposure can reduce long-term performance.
How to Maximize Solar Panel Efficiency Over Time
Solar panel efficiency naturally declines over time due to factors like environmental exposure and material degradation. However, with proper care and maintenance, you can minimize this efficiency loss and keep your system performing at its best.
The following strategies focus on preserving and maximizing solar panel efficiency throughout the lifespan of your installation.
Regular Cleaning and Inspections
Routine cleaning of solar panels can significantly improve energy output. Studies have found that dust can reduce the power output of PV modules by 50% when solar panels are not cleaned for approximately six months. Even a thin layer of dust or dirt can block sunlight, reducing the panels’ ability to generate electricity.
Consistent cleaning and solar panel maintenance ensures maximum light absorption, helping your system operate closer to its rated capacity and extending its effective lifespan.
Monitor Energy Production
Keeping track of your solar system’s energy output is an important part of maintaining its health and efficiency. Monitoring provides real-time data that reveals how well your panels are performing under various conditions.
This allows you to quickly identify any performance drops caused by issues such as shading, dirt accumulation, wiring faults, or equipment malfunctions.
Early detection of these problems enables corrective actions before significant efficiency losses or system downtime occur. Monitoring also helps optimize energy generation through adjustments to system settings or maintenance schedules based on actual performance data.
This proactive approach maximizes your solar investment by ensuring your panels operate as close to their peak efficiency as possible over the long term.
Choose High-Efficiency Panels
Selecting solar panels with high efficiency ratings—typically 20% or higher—ensures greater energy output from the same surface area compared to standard panels with efficiencies around 15-18%. Technologies such as monocrystalline silicon cells and passivated emitter rear cell (PERC) designs contribute to these higher efficiencies.
Premium panels often feature better durability, improved temperature coefficients, and longer warranties, which help maintain performance and reliability over the system’s lifespan. Investing in these quality panels establishes a strong foundation for maximizing your solar energy production and long-term savings.
Let’s Recap
Solar panel efficiency naturally declines over time, typically losing around 0.5% to 0.8% per year due to material wear and environmental exposure. Despite this gradual degradation, most high-quality panels retain approximately 85% to 90% of their original output after 25 to 30 years, making them a reliable long-term investment.
Environmental conditions such as elevated temperatures, high humidity, and prolonged UV exposure can accelerate efficiency loss. Choosing high-efficiency panels, particularly those utilizing advanced technologies like monocrystalline silicon and PERC designs, provides greater energy output and enhanced durability.
Pairing this with regular maintenance practices, such as cleaning and performance monitoring, ensures your solar system operates near peak efficiency, delivering consistent energy production and maximizing your return over time.
Why Choose Rivertown Solar?
Rivertown Solar is a trusted solar energy partner serving homeowners across Westchester County. With extensive local experience, we understand how regional climate conditions, regulations, and permitting impact solar panel performance and longevity.
Our team provides high-efficiency solar panels and customized systems designed to maximize energy output and durability for your specific home environment. From initial consultation to seamless installation, we ensure a smooth process backed by transparent pricing, robust warranties, and dedicated local support that continues long after your system is up and running.
Take charge of your solar investment with a partner committed to helping you achieve the highest possible efficiency and savings. Contact Rivertown Solar today for a free consultation and learn how to get the most from your solar panels over time.
FAQ
How long do solar panels last?
Most solar panels are designed to last 25 to 30 years or more. However, multiple factors—such as the quality of materials, installation, and local environmental conditions—can influence this lifespan. Even after several decades, well-maintained panels often continue producing electricity at a slightly reduced rate.
What is the degradation rate of a solar system?
On average, solar panels degrade at a rate of about 0.5% to 0.8% per year. This means their ability to convert sunlight into energy gradually declines, but high-quality systems are engineered to degrade more slowly and maintain solid performance over time.
How efficient are solar panels after 5 years?
After five years, most solar panels maintain about 90% to 97.5% of their original efficiency rate. This slight decline is normal and expected due to gradual wear and tear, but premium panels typically retain strong performance well beyond the five-year mark.
What causes solar panels to lose efficiency?
Several environmental and material factors can cause solar panels to lose efficiency over time. Excessive heat, high humidity, and prolonged UV radiation can all contribute to degradation. Physical wear and tear from snow, hail, or debris, along with panel quality, also play a role in how quickly performance declines.
What are the most efficient solar panels?
The most efficient solar panels on the market are monocrystalline panels, known for their high efficiency rate, typically between 20% and 23%. These top-performing systems are often considered the best solar panels for maximizing solar production, especially when roof space is limited.
Can you extend the lifespan of a solar panel?
Yes. Regular maintenance—such as cleaning, inspecting for damage, and monitoring solar production—can help extend your solar system's lifespan and preserve its efficiency. Choosing durable, high-efficiency panels and protecting them from harsh weather conditions are also key steps in maximizing long-term performance.