How long do solar panels last?

Wondering how long a set of solar panels will last, or how to keep them performing at their best for as long as possible? This article will explore all the factors that can affect the longevity of solar panels, from installation to maintenance and beyond.

If you’re wondering how much a solar & battery system could save you, just answer a few quick questions below and we'll generate an estimate for you.

What’s the average lifespan of a solar panel?

The average lifespan of a solar panel is typically around 30 to 40 years. However, this doesn't mean the panel suddenly stops working at that point - it just becomes less efficient at converting daylight into electricity.

As long as your solar panels are good quality and you've kept on top of your solar panel maintenance, your system should continue to function well beyond its average lifespan.

How long is a solar panel’s warranty?

Solar panels usually come with two types of warranties:

1. A product warranty
2. A performance warranty

The product warranty covers defects in the solar panel itself and typically covers around 20-25 years, although some manufacturers offer longer warranties up to 30 years or beyond.

The performance warranty guarantees that the solar panels will produce a certain percentage of their rated power output over time, usually promising around 80-90% of their original output by the end of the warranty period.

These warranties protect your solar investment by making sure the panels work as they should for a long time.

Monocrystalline vs polycrystalline solar panel lifespan

Black monocrystalline solar panels tend to last up to 40 years, although most don’t come with warranties that exceed 30 years. Meanwhile, blue polycrystalline solar panels will start to struggle slightly sooner - usually at the 25-year or 30-year mark - and come with a shorter warranty. 

Monocrystalline solar panels beat their blue counterparts on almost all fronts, including appearance, efficiency, and durability. The main advantage of polycrystalline solar panels is simply that they’re a bit cheaper, due to the fact they’re not as effective. 

To find out more, check out our guide to why black solar panels are better than blue.

Has solar panel lifespan improved?

Surprisingly, solar panel lifespan has always been extremely good. Given they have no moving parts, there is rarely something that can go wrong within the solar panel itself, which means they can keep generating electricity for a very long time. 

However, what has improved is the level a solar panel will be performing at after 25 years of usage. Solar panels naturally degrade throughout their lifespan (see below), but with newer solar panels starting at a much higher efficiency, this means that their performance level after 25 years will be higher than older models. There have been regular breakthroughs in solar panel efficiency over the past fifty years (check out the chart in our guide to solar panel efficiency).

What’s more, advances in materials and manufacturing processes have made solar panels more durable and resistant to extreme temperatures and challenging weather conditions over the years. This isn’t particularly relevant to the UK’s mild weather, but is helpful in countries with much harsher conditions.

All of this means solar panels have become an even better long term investment, which is important given the high upfront cost of solar.

To learn more, check out our article about whether solar panels are improving.

Curious about the savings you could get from a solar & battery system? Answer a few quick questions below and we’ll provide an estimate.

Do solar panels degrade over their lifetime?

Yes, a solar panel goes through a natural degradation process as part of its lifecycle. This means that its ability to convert daylight into electricity is very slightly reduced each year. 

Why do solar panels degrade?

Solar panels degrade mainly because of exposure to the elements.

Ironically, daylight and high temperatures can wear down a solar panel’s materials over time, while extreme temperature swings cause expansion and contraction, leading to potential cracks. Humidity, salty sea air, and the physical impact of things like hail or debris can also damage panels.

All these factors come together and make a solar panel less efficient as it gets older.

What’s the annual degradation of solar panels?

On average, solar panels lose at least 0.5% of their efficiency per year according to research by the National Renewable Energy Laboratory (NREL, 2015). Despite this research being almost ten years old, most premium solar panels today will still see a 0.5-1% drop in efficiency after their first year of use. 

After 25 years, most monocrystalline solar panels on the residential market tend to produce somewhere between 80-90% of their original power output.

To learn more about solar, check out our rundown the top 17 facts about solar panels.

Typical degradation of a solar panel over 30 years

How reliable are solar panels?

Solar panels are sturdy, designed to withstand heavy downpours, heatwaves and high winds, and they even work in the winter. It's rare for solar panels to just stop working - most issues come from external factors like shading, dirt accumulation, or installation errors. In fact, the part of a solar PV system that typically encounters the most issues is the inverter. 

With proper installation and maintenance, a solar panel can produce electricity reliably over its lifespan.

Can solar panels catch fire?

Solar panels themselves are very unlikely to catch fire. Fires from solar panels are extremely rare and are usually caused by a faulty installation or incorrect wiring.

For example, if the electrical systems connected to the solar panels are installed poorly, it could lead to short circuits or overheating, increasing the risk of catastrophic fires - like the one caused by an alleged faulty installation in 2021.

Do solar panels need cooling?

Solar panels are durable enough not to need special cooling, especially in the UK.

In high temperatures, solar panels can be cooled passively by ensuring good airflow around the panels or actively using water cooling systems, where water is circulated behind the panels to absorb excess heat.

Solar panels rarely require active cooling, unless they're installed in sweltering climates (not quite the UK, yet). In large solar power plants, active cooling is the norm, but for residential systems, enough spacing and ventilation usually do the trick.

How to make your solar panels last as long as possible

If you want your solar panels to last and perform well, you need to take care of them properly from the beginning and throughout their lifecycle.

Here's how to make your solar panels last as long as possible:

• Use a good installer
• Check their output
• Keep them clean
• Pay for maintenance checks

Use a good installer

Make sure you find a reliable installer for a top-quality solar panel installation. A skilled installer decreases the chance of future problems and uses high-quality hardware that lasts longer, securing the efficiency and longevity of your solar panel system. 

Check their output

Most solar systems are equipped with an app that allows you to monitor their output, which is measured by the inverter. You can use this feature to find and fix any issues right away.

Rather not take on that responsibility? Sunsave Plus, the UK’s first ever solar panel subscription, offers 20 years of monitoring and maintenance support where professionals monitor your system remotely and take care of detecting and fixing any issues.

Keep them clean

Solar panels are largely self-cleaning, as they have a hydrophobic coating which means rainwater naturally washes away most dirt and debris.

However, if you live in a very dry and dusty area, it can be necessary to give your solar panels a clean every couple of years, to ensure that your system doesn't become less efficient.

That said, don't risk the danger of climbing onto the roof to do so - instead, we recommend using an extendable soft brush from ground level, or calling in a professional. Many window cleaners around the UK also offer solar panel cleaning as a service.

To learn more, check out our guide to solar panel cleaning.

Pay for maintenance checks

The Microgeneration Certification Scheme (MCS) suggests conducting a basic maintenance check every 10 years and a more comprehensive inspection every 15 years.

These checks make sure everything is in tip top shape - from the panels and wiring to the overall performance of your system - so it works perfectly over its lifespan.

Summary

With the right care, solar panels are a reliable electricity source, lasting up to 25 years and beyond. A little maintenance goes a long way in ensuring your solar panels work efficiently year after year.

For a rough guide on how much a solar & battery could save you, provide us with a few quick details below and we'll generate a quick estimate for you.

Solar panel lifespan: FAQs