You will also want to think carefully about which kind of solar inverter works best with your solar energy system and roof. Solar inverters convert the DC electricity that comes from the solar panels into AC electricity that is usable in your house. Choosing a solar inverter can get a little confusing, so it may be best to simply talk to local solar installation contractors about your specific needs.
There are three basic kinds of solar inverters:
- Central or String
- Power optimizers
String inverters are the most common types of inverters found in home solar energy systems. Not surprisingly, they also happen to cost the least. They are ideal for well-lit roofs with little shade and a flat plane.
The term “string” refers to the way the solar panels are situated when they are connected to this kind of inverter. The panels are arranged in strings connected parallel to each other and then tied to the inverter.
String inverters are an older technology compared to power optimizers and microinverters. Often described as module-level power electronics (MLPE), they represent a newer innovation that offers certain advantages where string inverters fail. Specifically, MLPE’s can maintain high efficiencies on roofs that have multiple levels or partial shade.
Microinverters convert power from DC to AC within each panel. Sometimes a solar panel comes with the microinverter embedded, and other times the inverter is added separately. Microinverters offer high energy efficiency because a panel on a shaded part of the roof doesn’t block energy flow from a solar conversion occurring within a panel on a sunny portion. This is a benefit of each panel operating autonomously.
Microinverters represent the most expensive of the three conversion technologies.
Like microinverters, power optimizers are embedded in the solar cell. So they also perform well where roofs are partially in shade. But the electricity from an optimizer goes through an additional step, one not undertaken by the other kinds of solar cells. When power leaves the power optimizer cell, it undergoes conditioning, which leads to higher efficiencies for the cells.
Power optimizers are less costly than microinverters but more costly than string inverters.