Wondering how long solar panels last and whether their performance declines with age? You’re not alone. Solar panel degradation is a common concern among homeowners considering solar — and it’s a key factor in understanding long-term savings. In this post, we’ll explore what degradation means, how much production you lose over time, and how to design your system to stay ahead of the curve — especially in Texas.
What Is Solar Panel Degradation?
Solar panel degradation refers to the gradual decline in energy output as panels age. This is a completely normal process caused by environmental exposure, UV radiation, heat cycles, and material fatigue over decades of use.
It doesn’t mean your panels will suddenly stop working — they just slowly produce a little less energy each year.
How Fast Do Panels Degrade?
The average degradation rate for most solar panels is about 0.5% to 0.7% per year. That means:
- After 10 years, your system may produce ~95% of its original capacity
- After 25 years, it could be closer to 85%–88%
Premium solar panels, like those from Q CELLS or REC, often have degradation rates closer to 0.25% per year, meaning they retain over 92% of production capacity after 25 years.
How Degradation Is Tested
Solar manufacturers subject their panels to accelerated aging tests using UV light, temperature changes, and mechanical stress to simulate real-world wear. The results are then used to define performance warranties — typically 25 years.
A 25-year linear performance warranty might guarantee:
- 97% production in year 1
- No more than 0.5% drop per year
- No less than 85% production by year 25
This helps you understand the worst-case scenario — and most panels often outperform these numbers.
Real-World Impact on Energy Production
Let’s say you install a 10 kW solar system producing 14,000 kWh per year.
- Year 1: 14,000 kWh
- Year 10 (at 0.5% degradation): ~13,330 kWh
- Year 25: ~11,900 kWh
That’s a 15% drop over 25 years — not dramatic, but it does add up when calculating your long-term savings.
Why This Matters in Texas
Texas homeowners — especially in deregulated areas like DFW — face a unique energy billing structure. Even if you install a solar system that matches your current annual usage, you may not offset your future electric bills fully unless you account for degradation and inflation.
Also, TDU delivery fees from Oncor and monthly basic customer charges often can’t be eliminated unless you have:
- A buyback plan that credits you for exports at retail and includes TDU fees (rare), or
- A battery system to avoid importing energy during expensive times
Design Tip: Go For a Higher Offset Upfront
To account for degradation, many homeowners choose to oversize their system by 5%–10%, especially if:
- You expect your usage to increase (EV, pool, growing family)
- You want to stay as close to net-zero as possible long-term
- You live in Texas and want to minimize Oncor delivery charges
For example, if your home uses 13,000 kWh per year, consider a system sized to produce 13,650–14,300 kWh/year to offset degradation and future needs.
This is a smarter strategy than trying to expand your system later, which often requires separate interconnection, permitting, and can’t be financed as easily.
Solar Panel Warranties & Degradation
Most panels come with two warranties:
- Product Warranty (10–25 years): Covers physical defects
- Performance Warranty (usually 25 years): Guarantees minimal degradation rate
Eagle Mountain Solar only works with panels that offer industry-leading warranties. And because we’re partnered with Powur’s 30-year system warranty, you’re also protected on labor, inverters, roof penetration, and more — giving you peace of mind beyond what most local installers offer.
Batteries as a Future-Proof Solution
With solar exports becoming less valuable in many markets (as seen in California under NEM 3.0), batteries are becoming the smartest way to maximize self-consumption and reduce reliance on the grid.
In deregulated Texas markets, buyback plans rarely cover TDU delivery fees, so even if you export more than you import, your bill may not go to zero.
Adding a battery allows you to:
- Store excess solar during the day
- Use that stored energy at night
- Avoid expensive import charges and TDU fees
- Keep the lights on during blackouts
Future-proofing your system with a battery — even if you don’t install it right away — ensures you’re protected as utility rate structures change.
Summary: Why Degradation Shouldn’t Deter You
Solar degradation is real — but it’s predictable and manageable.
Here’s what to keep in mind:
- Most panels degrade 0.3%–0.7% per year
- After 25 years, you’ll likely still produce 85%–92% of your original output
- Oversizing your system by 5–10% can help you maintain energy independence
- High-quality panels degrade more slowly and retain more value
- Batteries help avoid TDU fees and protect you from future billing changes
With expert design, quality components, and honest consulting, solar can still provide massive savings and long-term value — even as systems age.
Ready to Future-Proof Your Energy?
At Eagle Mountain Solar, we help you size your system smartly — with degradation, usage trends, and rate structures in mind. Whether you want maximum offset or a flexible battery-ready setup, we’ve got your back with transparent proposals, vetted installers, and financing tailored to your goals.
Schedule your free consultation today and see how solar can work for you — now and 25 years from now.
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