If you're considering installing solar panels on your rooftop or on your property, you have to calculate all the costs involved. At first glance, the deal seems almost too good to be true: free energy and higher home value, all for a modest investment. But how long do solar panels last? Will your investment hold up or cost you dearly?
How Long do Solar Panels Last?
Modern solar panels will last over 25 years, with most manufacturer warranties ranging between 25 and 30 years. This is plenty of time for you to recoup your investment in a solar roof array. But even when those 25 or 30 years are up, your solar panels still have plenty of life in them.
We're used to thinking of devices as either working, or broken. Light bulbs are the perfect example. One day they work; the next day they're burnt out. But solar panels don't really operate this way. To understand more about solar panel life expectancy, we have to understand what they are made of and how they can fail over time. The question isn't really how long do solar panels last, but how long do their individual parts last.
Do Solar Panels Fail?
Unless some major accident occurs, like a meteorite crashing into your roof and knocking out a panel or two, solar panels won't just die overnight. A solar panel is actually made up of dozens of smaller solar cells. When their power is combined, they produce enough energy to power the devices in your home.
These individual solar cells can fail due toa number of factors. The most common is thermal cycling, which is when something changes from hot to cold or vice-versaover and over again.
Thermal cycling can cause tiny cracks and separate solder joints inside the cell.
The second leading cause is humidity or moisture getting trapped inside the cell, followed by a temperature change. Frozen moisture can separate the cell from the rest of the panel, or cause physical trauma. It's the same reason the roads tend to deteriorate in winter. So while your entire panel shouldn't fail all at once, over time several of those tiny cells inside it could die out. That process is called solar panel degradation.
What Causes Solar Panels to Degrade?
Beyond the aforementioned processes of thermal cycling and humidity, there are other risks to solar panels over time. For example, UV radiation, an unavoidable part of dealing with the sun's energy, breaks down the chemicals inside a solar panel.
Physical damage is also one of the leading factors limiting solar panel lifespans. Obviously you should never walk or place objects on your solar panels. Installation should be done by professionals who know how to handle these delicate objects with care.
But even with a perfect installation and good maintenance, your solar panels can still end up getting bumped and bruised. The panel is surrounded by a metal frame, and manufacturers have sometimes taken to using lighter materials for this frame. Under heavy snow, the frame can bend if it's not rigid enough, and that can crack some of the cells inside the panel.
What Happens When a Solar Panel Degrades?
Instead of simply malfunctioning, the solar panel is able to capture whatever energy trickles out of it. If you lose 10% of the cells inside the panel, it would still produce 90% of its original energy output. A degrading solar panel simply produces less power than it did when you first installed it.
Solar panels used to degrade much more rapidly than they do now. In the 70s and 80s, they would lose up to 3 or 4% of their performance each year! Today, those numbers are much lower. Modern solar panels degrade at less than 1% per year.
This is why we see life expectancies of 25-30 years, it takes about that long to reach 80% of the original performance. 80% is the industry standard limit, and panels below that should be marked for replacement.
Can You Extend the Life of Solar Panels?
How long do solar panels last if you take good care of them? Can you extend their lifespan? While you can't avoid some of the degradation, you can certainly do your best not to harm your panels any further. If you live in an area that gets heavy snowfalls in winter, consider taking the time to remove the snow from your panels. That added snow weight can do damage over time.
If you live on a dirt road which gets significant traffic, you should schedule regular cleanings of your solar panels as well. Ditto for rooftops that seem destined to get hit by flocks of birds passing overhead.
Otherwise, there isn't a whole lot more you can do. Unlike your phone, you can't just put a protector over the top of the panel, since that would cut down the available sunlight and defeat the purpose of using the panel in the first place. The best thing you can do is follow the manufacturer's advice and take care of your panels.
How Long Does It Take for Solar Panels to Become Profitable?
How long do solar panels last? Long enough for you to make a profit! Everyone wants to know how long it takes for solar panels to pay for themselves. The answer depends entirely on your energy consumption, the type of panels you buy, where you live, and even whether you can sell excess power back to the utility company or to the grid.
Let's take a look at the average American home, which uses about 860 kilowatt hours per month. A typical roof can accommodate a 5kWh array of solar panels. Assuming you get about 6 hours of quality sunlight per day, that's enough for 30kWh a day, or 900kWh per year. That would completely replace your electricity costs! Using the national average of 11 cents per kWh, you could save up to $95 a month. That's $1140 a year.
Installation costs for a 5kWh system range between $10,000 and $20,000 depending on your location. Let's take the middle number and assume it'll cost $15,000. At that price, it'll take you around 13 years to pay off the cost of your solar panel installation. 13 years seems like an awful long time. But when you consider that adding solar panels also increases the value of your house, then it's not such a bad proposition after all.
The main caveat here is that most homes aren't actually average. If you live in a place with long, heavy snow seasons (like Maine or Wisconsin) or where you're subject to hurricanes and strong storms, your solar panel will take a lot longer to become profitable; if that's even possible before it needs to be replaces. The same is true if you live in a place where you just don't get enough sunny days to create the energy you need.
Should You Replace Old Solar Panels?
Whether you should replace your old solar panels or not depends on a few factors. First, how old are the panels? If they were installed before 2000, chances are they weren't the most efficient panels to begin with. You might benefit from a fresh installation.
But if your panels are newer than that, you're safe until you reach the 25 to 30 year mark. Analyze how much energy you are using and if it's worth installing new panels.
Even at 80% of their original efficiency, your existing installation could still be good enough to keep the lights on in your home.
You may be able to get more utility out of your solar panels by installing a battery system for your home. This will let you use solar energy captured during the day when you come home at night. If you're at work all day and the kids are at school, this option can make the most sense; and, it will add to the value of your home.
Before you decide to replace an older array of solar panels, do some research and see what new technologies are on the horizon. The cost and efficiency of solar panels has steadily improved over the last decade. You can expect that trend to continue, and in some cases it might be worth holding off another few years before replacing your existing panels.
The answer to the question “How long do solar panels last” may change in just a few years. A few decades ago, the answer was 10 years; but now it's over 25! Any investment in solar power today is likely going to last you 30 years, and even after that it'll still keep producing power.
Modern setups are capable of producing more power at 80% of their original strength. As solar technology matures and more breakthroughs occur, you can expect better products to hit the market at even better prices.
In addition to the savings on your monthly electric bill, adding solar panels to your home adds value that lasts even beyond the manufacturer's warranty. So go ahead, put those panels up and let them shine. Your wallet and your planet will thank you for making such a bright choice.