There are several key decisions home owners need to make when considering solar panel installation. One of these is the type of inverter you want to have installed in your system. Inverters convert direct current (DC) energy generated by your solar panels into usable alternating current (AC) energy. Inverters are the most important equipment in your solar power system after the panels themselves. Currently, there are three types of inverters available to choose from- string (aka centralized), micro, and power optimizers. Of these inverters, string inverters are the most commonly utilized. However, microinverters and power optimizers (jointly referred to as “Module-Level Power Electronics” or MLPEs) are becoming more popular due to their reducing costs.
What’s the difference between the three inverters?
String inverters have been used for decades. Most companies will generally offer you a system with a string inverter if your roof is not heavily shaded and does not face multiple directions. During installation, solar panels are arranged into groups connected by “strings.” Each string of panels is connected to one inverter. This one inverter, the string inverter, transforms the DC electricity into the usable AC electricity. The thing with string inverters is a string of solar panels will only produce as much electricity as its least productive panel. In other words, if you have one or more solar panels being shaded at all throughout the day, the entire string will only produce the amount of power that shaded panel will allow. This is why if you have a roof that faces multiple directions or is shaded, string inverters would not be a good choice
Microinverters are gaining more popularity due to their effectiveness, easier installation, and because the cost has remarkably declined. The difference with microinverters is that they are installed on or within each individual panel in a solar system. This allows them to convert the DC electricity from your solar panels into AC electricity without needing a separate central (or string) inverter. Because DC-AC conversion happens on the panel level, there’s never any high-voltage power traveling through your system. Low voltage DC never exceeds 60 volts. With microinverters, only the individual panels are affected if there is any obstruction or shading. The other panels continue to perform at their fullest, leaving you with more solar energy production. Another advantage to microinverters is that they allow you to monitor the performance of individual solar panel. When something goes wrong, you can pinpoint where and why. There is no single point of failure either. If one panel goes out, productivity continues in the rest of the system. With that said, microinverters also come with a 25 year warranty. This is longer than that of string inverters or power optimizers, which are usually 12 years.
Like microinverters, power optimizers are located on each panel, but optimizers typically require the installer to mount one or more heavy inverters on the wall as well. Optimizers do come with the ability to monitor your system. However, because they are also working with a string inverter, it tends to have a single point of system failure. If the string inverter goes out, the system goes offline. Power optimizers are slightly cheaper than microinverters, but when you look at the productivity, reliability, and warranty, there’s no comparing.
WattSun Solar uses the effective and more reliable choice of microinverters. If you have any further questions regarding these, please speak with your WattSun installer today!