One of the most common questions we hear from homeowners considering a solar panel installation is, “how long will my solar panels last?” It’s hard to make sense of the upfront cost of going solar without knowing how long you can expect that small power plant on your roof to produce ample energy. Your solar panels will be able to offset your electricity use for decades, but it is also important to understand industry projections and degradation rate. In this article, we’ll break down everything you need to know about solar panel lifespan.
What is the lifespan of a solar panel?
The industry rule of thumb, based on advanced testing by manufacturers, is that your solar panels will last 25-30 years. However, this doesn’t mean that they stop producing electricity after 25 years – it just means that energy production has declined by what manufacturers consider a significant amount.
Solar panel degradation rate
A 2012 study by the National Renewable Energy Laboratory (NREL) found that, on average, solar panel output falls by 0.8 percent each year. This rate of decline is called solar panel degradation rate. Though this rate of decline metric will vary depending on which panel brand you buy, premium manufacturers like SunPower offer degradation rates as low as 0.3%.
This means that with non-SunPower equipment, in year two, your panels will operate at 99.2 percent of their original output; by the end of their 25-year “useful lifespan,” they will still be operating at 82.5 percent. In the years since this 2012 study has been conducted, more efficient technologies have been developed and many newer panels have just a 0.5 percent yearly decline in energy output.
Solar panels also come with a few different warranties that can give you a sense of just how long you can expect your solar panel’s lifespan to be. Manufacturers will offer both an equipment warranty, to certify against manufacturing defects, and a performance warranty, to guarantee that your panels will produce a certain amount of electricity. Your solar panel’s performance warranty, which typically lasts 25 years, can give you a better sense of how much electricity to expect from your solar panel system over time.
You don’t need to worry about the carbon footprint of your solar panels, either. The 25 to 30 year lifespan of a solar panel is significantly longer than its “energy payback time,” or EPBT. EPBT is the amount of time it takes for a solar panel to produce enough clean electricity to “pay back” the energy that was used to manufacture it in the first place. A 2010 analysis from Brookhaven National Laboratory found that the EPBT of a solar panel is just six months – a number that has surely fallen in the past six years as panel manufacturing becomes more efficient.
Can you make solar panels last longer?
In general, solar panels are extremely durable. Most manufacturers test their panels to confirm that they can withstand high winds and heavy snow loads, and many solar panels are specifically tested to ensure that they can withstand falling hail. Additionally, solar energy systems don’t usually have moving parts, and they require little to no maintenance.
That being said, keeping your solar panel system well maintained can lead to a lower degradation rate each year and can promise longer panel performance. Making sure to brush snow, leaves or other debris off of your panels in addition to maximizing light exposure whenever possible, such as removing trees or shading branches, can help your panels produce longer for your home. Additionally, buying better solar equipment will lead to a longer solar panel lifespan. There is a reason SunPower has much longer warranties than most panel manufacturers – their products are built to last and built to perform long term.
Even more than just the panel equipment themselves, inverters will impact how long your panels can last depending on which type you buy. A typical central inverter for a PV installation will last between 10 and 15 years and thus will need to be replaced at some point during the lifetime of your solar panels. However, micro inverters are a new and popular alternative to central inverters and generally offer the same lifespan as their solar panel counterparts – 25 years.
Finding a sustainable solar solution for your home is easy
Going solar is an investment in the earth’s future that can also reduce your monthly electric bills. By thoroughly researching solar equipment manufacturers and working with a solar installer that offers the products you want, you can ensure that your solar panel system is as sustainable as possible. Compare solar quotes side-by-side the EnergySage Solar Marketplace to find the right combination of sustainable products, easy financing options, and a well-reviewed installer for your home’s renewable energy needs.
This post originally appeared on Mother Earth News.