So you’ve got a shiny new solar installation on your roof, and it’s just started kicking out the kilowatts. How do you know that every panel is producing up to its potential? What if one or more of your solar panels breaks? Will the others keep working?
These are all excellent questions, and, fortunately, they’re also pretty easy to answer. But first let’s get into the particulars of how solar panel systems are set up:
With One Inverter
For a traditional solar panel system, panels are placed on the roof, and rows of panels are wired in strings. The strings are connected at one end of the system and the wires are run to a central inverter, which takes the DC electricity from the panels and changes it to AC electricity that can be used by your home appliances and the rest of the electrical grid.
In this kind of system, if a single panel isn’t working, the whole string goes down, kind of like if you cover half the panel on a solar calculator with your finger, the calculator won’t work.
This loss of power can also be experienced if a couple of your panels are extra dirty or shaded. You’ll know if a panel in your system has problems because the system output in kilowatt hours (kWh) will be lower than it should be. Many companies that install solar panels offer some kind of system monitoring software that can help.
If you suspect a problem and your system is within its installation warranty period (typically 10 years), call your installer to have them come check each panel. If your system is outside the installation warranty period but within the manufacturer’s panel warranty (typically 25 years), you may have to do a little bit of work to coordinate the repairs.
If your panels have been up for a while, you might be able to tell easily by looking at your electric bill whether your system is producing, but if you’ve just had panels installed, you’ll have to go by estimates provided by your installer (or you can take a look at our handy calculator to see how much energy your panels should be producing). Remember that even a little shading on a couple panels in a string can cause a big dip in production for that string.
Many modern solar panel systems are installed with micro-inverters attached to each panel. While these micro-inverters can be more expensive than a single, centrally-located inverter, they also separate each panel’s production, meaning when one goes down, the others keep working great. For systems that use micro-inverters, there is even more advanced monitoring software that can detect when one panel goes out.
Just your friendly neighborhood micro-inverter, hanging out under a solar panel.
That means your panels’ output shouldn’t decrease for any reason less than a lightning strike or other act of whatever-deity-you’re-into. That’s great news! So when you’re talking to an installer about getting a system, examine the micro-inverter option carefully. It might cost you a bit more up front, but it pays for itself in piece of mind and risk avoidance. Some micro-inverters are even warrantied for 25 years just like the panels, so they’re more durable, too.
Either way, make sure you’re getting the option for monitoring software, so you can know your typical production and be ready to take action if your system isn’t working like it’s supposed to.
Last modified: October 18, 2016