One of the fairest questions a Minnesota homeowner asks before going solar is simple: will these panels still work in 20 years? The answer is yes, but they’ll produce a little less than on day one. That slow fade is called solar panel degradation, and in Minnesota it’s worth understanding clearly, because it directly affects the long-term savings math you’re basing a big decision on.

What Degradation Actually Means

Solar panels lose a small fraction of their output each year. It’s not a failure or a defect. It’s the gradual, expected effect of decades of sun, temperature swings, and weather on the materials inside the panel. Manufacturers measure this and publish a degradation rate, usually expressed as a percentage of output lost per year.

The important thing to grasp is the scale. Degradation is slow and predictable, not a cliff. A panel doesn’t work great for 15 years and then quit. It works a hair less efficiently each year, so gradually that most homeowners never notice it in their monthly production. The reason it matters is cumulative: over 25 years, those small annual losses add up to a meaningful, but modest, difference you should plan for.

Typical Degradation Rates and What They Mean

Modern quality panels degrade slowly. Manufacturers commonly warranty their panels to retain a strong majority of their original output after 25 years, and premium panels hold up even better. Rather than fixate on a single number, the useful way to read it is this: a good panel that starts at full output will still be producing the large majority of that output decades later.

Here’s how a slow annual degradation rate plays out over the life of a system, so you can see why the yearly figure sounds scarier than it is.

Those figures are illustrative of a well-made panel; your exact numbers depend on the specific product, which is why we match Minnesota homes to durable panels and put the actual warranty terms in front of you. You can review the current lineup and their warranties on our panel recommendations page.

Does Minnesota’s Climate Speed Up Degradation?

This is the part that surprises people. Heat is one of the biggest drivers of panel degradation, and Minnesota is cold. Panels in hot desert climates run hot for much of the year, which stresses the materials and accelerates wear. Our long, cold winters actually work in a panel’s favor on this front. Cold, clear air is easy on the equipment and even improves instantaneous efficiency.

Our real climate stressors are different: snow load, hail, and freeze-thaw cycling. Quality panels are engineered and rated for all three, tested to withstand significant snow loads and hail impacts. Snow that sits on panels temporarily reduces production but doesn’t degrade the panel, and it typically slides off pitched arrays as they warm. So while Minnesota is hard on a lot of things, it’s genuinely one of the gentler climates for long-term panel health. Our deeper look at whether solar is worth it in Minnesota folds this durability into the savings picture.

How Degradation Affects Your Savings Math

Because degradation is slow and predictable, a good solar proposal already accounts for it. When we model your production and savings, we build in the expected annual decline so the numbers you see are realistic across the full life of the system, not just year one. That’s the honest way to do it. A proposal that assumes day-one output forever is overselling you.

Even with degradation factored in, a well-designed Minnesota system typically produces the vast majority of its lifetime energy in years where you’re well past your payback point. The panels keep earning long after they’ve paid for themselves. Financing plays into this too, since the system usually keeps producing long after a loan is paid off; current terms are on our financing options page. For the technical standards behind panel testing and reliability, the National Renewable Energy Laboratory publishes ongoing research on photovoltaic degradation.

The Honest Takeaway

Solar panel degradation in Minnesota is real, slow, and nothing to fear. Quality panels lose only a small fraction of output per year, our cold climate is easy on them, and any credible proposal already bakes the decline into your savings projection. What you’re really buying is decades of production, most of it well after the system has paid for itself.

Want to see degradation-adjusted numbers for your specific roof and Xcel bill? Reach out and we’ll model the full 25-year picture honestly.

Frequently Asked Questions

How much do solar panels degrade per year?
Quality modern panels typically degrade a small fraction of a percent to around half a percent per year, which is why they still produce the large majority of their original output after 25 years.

Do Minnesota winters damage solar panels?
No. Cold, clear air is actually easy on panels and improves efficiency. Quality panels are rated for Minnesota snow loads and hail, and snow that sits on them reduces production only temporarily without causing degradation.

Will my panels still work after 25 years?
Yes. Most quality panels are warrantied to still produce roughly 85% or more of their original output at 25 years, and they keep working beyond that, just at slightly reduced output.

Does heat make solar panels degrade faster?
Yes, heat is a major degradation driver, which is one reason Minnesota’s cold climate is favorable for long-term panel health compared to hot desert regions.

Is degradation included in solar savings estimates?
It should be. A credible proposal models the expected annual output decline across the system’s life so your savings projection is realistic, not based on day-one production forever.