Understanding the Lifespan of Solar Panels: Causes of Degradation and How to Extend Their Life

Solar panels are a crucial component of solar power systems, known for their long lifespan—typically 20 to 30 years. However, degradation over time can affect both performance and profits. This article explores the lifespan of solar panels, what causes their deterioration, and what you can do to maximize their service life.

What Is the Legal Useful Life of Solar Panels?

Legal Depreciation Period

について legal useful life (statutory depreciation period) is defined by governments for taxation purposes and represents the expected duration over which a solar panel system is economically depreciated.

According to Japanese standards (which are similar in many regions):

• 17 years for commercial resale use
• 9 years for self-consumption equipment

Keep in mind that this differs from actual usable life, which often exceeds 25 years, depending on product quality and maintenance.

Lifespan of Solar Panels and Related Equipment

🟩 Solar Panel Modules

Most panels function efficiently for 20–30 years, with performance warranties usually covering 25 years. There are cases where panels have continued operating effectively for over 30 years.

🟩 Power Conditioner (Inverter)

Inverters, or power conditioners, convert DC into AC electricity. Their lifespan is typically 10–15 years, shorter than the panels. Replacing them is often required mid-way through the panel’s life.

🟩 Feed-in Meters

Meters that track how much electricity is sold back to the grid must be replaced roughly every 10 years, depending on local regulations.

Causes of Solar Panel Degradation

Dirty Panel Surfaces

Dust, pollen, bird droppings, and yellow sand can block sunlight, cause hot spots, and reduce efficiency.

Prevention:

• Use anti-soiling coatings
• Conduct routine cleaning and inspections

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Mechanical Damage and Delamination

Temperature fluctuations, humidity, and impact can lead to delamination (layers peeling apart), reducing durability and waterproofing.

Corroded Wiring

Internal wiring can corrode due to high humidity, salt exposure, or poor installation. This increases electrical resistance and reduces power output.

What Happens When Panels Reach the End of Their Lifespan?

📉 Decreased Efficiency and Revenue Loss

Panels degrade by 0.25–0.5% per year on average. After 20–25 years, they generate noticeably less energy, which can reduce income from solar investments.

💸 Increased Repair and Replacement Costs

Inverters and wiring are typically the first to fail, leading to higher maintenance or replacement costs mid-life.

🗑️ Disposal Fees

Disposal of old panels can cost between $500–$2,000 per system, depending on local regulations and weight.

📉 Lower Resale Value

Old systems with limited functionality have reduced asset value and are harder to sell on the secondary market.

How to Prolong the Lifespan of Your Solar Panels

✅ Perform Regular Maintenance

• Clean panels periodically
• Inspect for cracks, wiring issues, and voltage irregularities
• Monitor power output with smart meters or tracking software

⏱️ Suggested Inspection Timeline:

• Initial check: 1 year after installation
• Follow-ups: Every 4 years, or immediately after severe weather

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✅ Choose Quality Panels and Skilled Installers

Select high-quality products with long-term warranties (20+ years) and use certified installers with a solid track record.

🔧 Browse:

• Roof Solar Mounting Systems
• Ground Solar Mounting Systems
• Solar Ballasted Roof Mounting Systems

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✅ Monitor Power Output Frequently

Keep track of your system’s generation over time. A sudden drop might indicate a hidden fault or physical damage.

✅ Review Warranty Coverage

Check both:

• Product Warranty (typically 10–15 years)
• Performance Warranty (typically 20–25 years)

Understand what’s covered and for how long—this can save significant repair costs later.

結論

Solar panels can serve as a long-term asset if maintained properly. While degradation is inevitable, strategic maintenance, quality components, and regular inspections can maximize their lifespan and returns.

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