How Long Do Solar Panels Last?

For most people looking at going solar there are usually two big questions. Firstly, most folks want to know how long do solar panels last, and secondly they want to know are solar panels worth it? The short answers are; a minimum of 25 years and YES, solar panels are definitely worth it!

It is quite unfortunate that so many people have to actually ask these questions because for anyone who knows anything about domestic solar power these days the answer is a no-brainer.

There has been a quiet green energy revolution happening due to a drastic price drop in the solar panel cost for the regular Joe consumer. Coupled with high energy prices and an economic depression this industry has been bubbling away under the surface and is ready to explode!

Solar Panel Lifespan

One of the hardest aspects of answering the ‘how long do solar panels last’ question is actually finding a decent amount of actual domestic solar panels which have been around for longer than 20 years and are still being used today. Believe me, there aren’t many out there.

Of the few that have been found by ourselves, and using information collated from other solar panel reviews, it has been found that the majority of the systems assessed are still producing electricity at around 80% of their original power output.

This includes a large sample of systems in California which were installed in the 1970’s, an amazing result!

Solar Panel Warranties

According to studies on rooftop solar panel systems it has been found that all types of solar panels lose about 0.5 – 1% efficiency per year. These findings are consistent with the observations of older installations showing that systems 20-30 years old which are still running at around 80% output have dropped efficiencies within this range.

The majority of solar roof panels come with 25 year warranties. While this is more than enough for most folks, it is becoming a well-known fact that your solar panels will last a lot longer than this if you look after them right. It’s just not practical to give warranties longer than 25 years due to the drop in efficiency.

How To Increase Your Solar Panel Lifespan

To get the most life out of solar panels for your home it’s important to know a little bit about maintenance.

Looking after your solar panels mainly consists of regular cleaning. When I say regular I don’t mean every day. Solar panels are relatively low maintenance. Keeping them clean with regular wipe downs to remove dust, dirt, smog, pollen and other airborne particles will increase the efficiency of the panels.

How often you do this cleaning will depend on your conditions and the weather. In windy areas and places known for dirty or dusty air, cleaning will obviously need to happen a bit more. Additionally, be sure to keep clear any obstructions which might get in the way of sunlight coming on to your panels. Trees should be trimmed regularly and if you have fixed obstructions such as power lines or buildings, seriously think about moving your panels because loss of light during any part of the day will drastically reduce your system efficiency and output.


It has been proven that solar panels last well over 30 years and can still produce over 80% of their original output. The best solar panels in terms of efficiency are monocrystalline solar panels because the silicon is more stable and they won’t lose efficiency as fast as polycrystalline panels or solar panel shingles.