How Long Do Solar Panels Last Without Sun?

The phrase “without sun” can refer to several scenarios, each with a different impact on solar panel performance and the duration for which a system can provide power.

Solar Panels at Night: Zero Production

• The Simple Answer: Solar panels produce no electricity at night. They require light (photons) to initiate the photovoltaic effect. When the sun sets, the photon supply ceases, and so does power generation from the panels themselves.
• How Your Home Stays Powered:
  • Grid-Tied Systems: Most residential solar systems are connected to the electrical grid. During the day, they produce electricity for your home and often send any excess back to the utility (net metering). At night, your home draws power directly from the grid. This is the most common and cost-effective solution for nighttime power.
  • Battery Storage Systems: Excess electricity generated during the day is stored for homes with solar batteries. At night, the home draws power from these batteries. This provides energy independence and backup power during grid outages.
  • Hybrid Systems: These combine grid connection with battery storage, offering the best of both worlds – grid reliability with backup power.

Solar Panels on Cloudy, Overcast, or Rainy Days: Reduced, Not Zero Production

• Performance in Low Light: Solar panels do work on cloudy, overcast, or rainy days, but their power production is significantly reduced. They rely on light, not necessarily direct sunlight. Diffused light (light scattered by clouds) can still be absorbed by the photovoltaic cells.
• Typical Output:
  • On heavily overcast days, solar panels might produce 10% to 25% of their normal output.
  • Under partly cloudy conditions, production can range from 50% to 80%.
• Impact on Lifespan: Cloudy days or periods of low light do not shorten the physical lifespan of solar panels. Cooler, cloudy conditions might even be slightly beneficial as panels operate more efficiently at lower temperatures (as discussed in our previous article on location’s role in efficiency).
• Role of Batteries and Grid: For continuous power during extended cloudy periods, your system will rely on either:
  • Stored energy in batteries: If your system includes energy storage.
  • Drawing power from the grid: For grid-tied systems.
  • Optimizing for Low Light: Modern solar panel technologies (e.g., Monocrystalline, N-type, HJT, IBC) often have superior low-light performance. Proper orientation, tilt, and keeping panels clean (rain helps, but manual cleaning is needed for dust) also enhance output in less-than-ideal conditions.

Solar Panels Under Heavy Shade or Snow: Significant Impact

• Heavy Shade: If solar panels are consistently under heavy shade from trees or buildings for significant parts of the day, their output will be severely hampered. Even partial shading on one cell can dramatically reduce the output of an entire string of panels. This can indirectly affect the system’s “lifespan” in terms of its economic viability if it consistently underperforms due to design flaws or unaddressed shading.
• Snow Cover: A layer of snow completely blocking the panels will result in zero power production until the snow melts or is removed. This is a temporary obstruction and does not damage the panels or shorten their lifespan.

Solar Panels During a Power Outage (Grid Down):

• Grid-Tied Systems Without Battery Backup: If the utility grid goes down, most grid-tied solar systems are legally required to shut down (anti-islanding). This is a safety measure to protect utility workers who might be repairing power lines. So, even if the sun is shining, your panels won’t produce power for your home during a grid outage unless you have a battery backup.
• Systems with Battery Backup: If you have a battery system, it will automatically disconnect from the grid and provide power to your home (or selected critical loads) during an outage. The solar panels will continue to charge the batteries during the day.

In essence, solar panels are designed to convert light into electricity. Without light (like at night), they produce nothing. With reduced light (cloudy days), they produce less. Their physical longevity isn’t impacted by these periods of non-production.

How Long Do Solar Panels Last in Florida?

Solar panels are remarkably durable, generally designed to last for a long time. The average lifespan across the industry is 25 to 30 years, often backed by performance warranties. However, specific environmental conditions in a location like Florida can influence this lifespan and degradation rate.

If You Don’t’ Know Which Tilt Angle Best For My Location You Can Calculate Your Best Solar Tilt Angle in Florida 

Solar Tilt Angle Calculator 

1. General Solar Panel Lifespan & Degradation Rate

• Average Lifespan: Most modern solar panels come with a 25-year to 30-year performance warranty. This warranty typically guarantees that the panels will still produce at least 80% to 87% of their original rated power output by the end of the warranty period.
• Degradation Rate: Solar panels naturally degrade over time, losing a small percentage of their efficiency each year. The industry average degradation rate is around 0.5% to 1% per year. After 25 years, a panel degrading at 0.5% per year would still operate at approximately 87.5% of its original capacity.
• Beyond 25-30 Years: Panels don’t suddenly stop working after their warranty expires. They continue to produce electricity, albeit at a slightly lower output. Many solar systems installed decades ago are still generating power today.

Florida’s Unique Environmental Factors and Their Impact

Florida’s climate presents specific challenges that can potentially affect solar panel longevity:

• High Heat and Humidity:
  
  
  • Impact: While Florida has abundant sunshine (great for irradiance), its intense heat and high humidity can accelerate the degradation of certain panel components, particularly the encapsulation materials and electrical contacts. As discussed, high temperatures reduce panel efficiency. Sustained heat can also cause thermal stress (expansion and contraction) on the materials. High humidity can contribute to “Potential Induced Degradation” (PID) in some panel types, though modern panels are largely resistant.
  • Mitigation: High-quality panels with good temperature coefficients and robust encapsulation (e.g., dual-glass panels) are more resilient. Proper ventilation during installation helps panels stay cooler.

• Hurricanes and Tropical Storms:
  
  
  • Impact: Florida is notorious for its hurricane season. Strong winds (up to 140-160 mph), heavy rainfall, and flying debris during hurricanes pose the most significant physical threat to solar panels. Panels can be torn off mounts, cracked by impacts, or have electrical components damaged by prolonged water exposure if the system is compromised.
  • Mitigation: Modern solar panels are designed to withstand high wind loads and undergo rigorous testing. Florida’s building codes often require PV arrays to meet higher durability standards. Choosing a certified, experienced installer who adheres to strict mounting standards and uses corrosion-resistant hardware is crucial. Impact-resistant glass and robust mounting structures (like those rated for high wind zones) provide added protection. Regular inspection and tightening of fasteners before hurricane season are also recommended.

   

•  Salty Air (Coastal Areas):
  
  
  • Impact: For homes near Florida’s extensive coastlines, salt mist in the air can be corrosive to metal components of solar panels (frames, mounting structures, wiring) and inverters over time. Salt buildup on the panel surface can also reduce efficiency by blocking sunlight.
  • Mitigation: Reputable manufacturers offer panels specifically designed and certified for marine or coastal environments (e.g., IEC 61701 Salt Mist Corrosion Test certification). Opting for corrosion-resistant materials like anodized aluminum or stainless steel for mounting hardware is essential. Regular cleaning of panels is vital to remove salt deposits. Ensuring inverters and other sensitive electrical components are housed in protected, dry locations is also important.
• High UV Exposure:
  
  
  • Impact: Florida’s intense sunshine means high UV exposure, which can slowly degrade the polymers and adhesives used in some solar panels, potentially affecting the anti-reflective coating or backsheet over many decades.
  • Mitigation: High-quality panels use UV-resistant materials and designs that minimize such degradation.

Factors That Extend Solar Panel Lifespan in Florida

Regardless of location, certain best practices ensure your solar panels last their maximum potential:

• Quality of Solar Panels: Investing in Tier-1 panels from reputable manufacturers (as discussed in previous interactions) is paramount. High-quality materials and stringent manufacturing processes lead to slower degradation and better resilience against environmental stressors.
• Quality of Installation: This is critical. A professional, experienced solar installer who understands local building codes (like Florida’s wind load requirements) ensures panels are securely mounted, properly wired, adequately ventilated, and correctly angled for optimal sun exposure. Poor installation is a leading cause of premature issues.
• Regular Maintenance and Cleaning: While solar panels are low-maintenance, periodic cleaning (especially in dusty or coastal Florida areas to remove dirt, pollen, and salt deposits) helps maintain efficiency. Regular professional inspections (every 1-2 years) can identify and address potential issues like loose wiring, micro-cracks, or corroded components before they escalate.
• Inverter and Other Components: While panels typically last 25-30+ years, inverters generally have a shorter lifespan (10-15 years for string inverters, 20-25 years for microinverters) and will likely need replacement at some point during the system’s life. Monitoring their performance and replacing them when needed ensures the overall system continues to function optimally.

Conclusion

In conclusion, solar panels are designed for remarkable longevity, capable of producing electricity for 25 to 30 years or more, even if they are not exposed to direct sunlight for extended periods (like at night or on cloudy days) or when the grid is down (if battery-equipped).

In challenging climates like Florida, the high heat, humidity, hurricanes, and salty air present unique environmental stressors. However, modern solar technology and strict installation standards ensure that panels can withstand these conditions effectively. 

By choosing high-quality panels, ensuring professional installation tailored to local conditions, and committing to regular maintenance, homeowners and businesses in Florida can expect their solar investment to provide clean, reliable power for decades to come, living up to its full potential regardless of the environmental challenges.

 FAQs

Q: Do solar panels produce electricity at night or during a power outage?

No, solar panels do not produce electricity at night as they require light. During a grid power outage, most standard grid-tied systems also shut down for safety, even if the sun is shining, unless you have a battery backup system.

Q: How much power do solar panels generate on cloudy days?

On heavily cloudy or overcast days, solar panels typically produce significantly less power, often ranging from 10% to 25% of their full capacity, as they still capture diffused sunlight.

Q: Does Florida’s intense heat and humidity shorten the life of solar panels?

 While high heat can slightly reduce immediate efficiency, modern solar panels are built to withstand hot and humid climates. High-quality panels and proper installation minimize long-term degradation from these factors.

Q: Are solar panels in Florida resistant to hurricane damage?

 Yes, solar panels installed in Florida must meet stringent building codes designed for high wind loads. With professional installation and robust mounting, they are highly resistant to hurricane-force winds and impacts.

Q: What is the typical lifespan of solar panels in a climate like Florida’s? 

High-quality solar panels generally last 25 to 30 years or more, even in Florida’s climate. They come with performance warranties guaranteeing a high percentage of original output after that period.