Types of solar inverters
There are three main types of inverter technologies available for your solar installation: string inverters, power optimizers, and microinverters. Both string inverters and power optimizer systems use a centralized string inverter to convert electricity from DC to AC, while microinverters convert DC electricity to AC electricity at the panel site.
String inverters join groups of solar panels in a system by “strings” that each connects to a single inverter where electricity gets converted from DC to AC electricity. While string inverters are typically the least expensive inverter option, one underperforming panel on a string can bring down the production every panel on that string. For this reason, string inverters are best suited for solar installations without any shading, and installations where all the panels are facing the same direction.
Power optimizers are located at each individual panel and are paired with a string inverter to complete the conversion from DC to AC electricity. Power optimizers don’t actually convert electricity to alternating current. Instead, they “condition” the DC electricity to optimize its voltage before sending it to a string inverter to be converted. This results in a higher overall system efficiency compared to using string inverters alone. Power optimizers also help reduce system inefficiencies by reducing the impact of shading or other factors reducing production at specific panels.
Microinverters are also located at each panel site, but are not paired with a string inverter. Unlike power optimizer systems, microinverters convert electricity from DC to AC right at the panel. This approach also leads to optimized electricity production when compared to using a string inverter alone. By converting DC electricity to AC electricity right at each panel site, microinverters cancel out the system-wide effects of a single panel underproducing.
Microinverters and power optimizers are often collectively referred to as Module-Level Power Electronics, or MLPEs for short. As a group, MLPEs offer several specific benefits when compared to traditional string inverters, including shade tolerance and individual panel monitoring options. However, MLPEs traditionally come with a higher price tag than string inverter options.