What is a solar inverter?

When you install a home solar panel system, the panels are just one piece of the puzzle. Another very important piece is the solar inverter—without it, you wouldn’t be able to use any of the electricity your solar panels produce.

A solar inverter converts the direct current (DC) electricity that solar panels produce into the alternating current (AC) electricity that our appliances run on. There are several types of solar power inverters and not all of them are made equal. We'll help you understand how solar inverters work and the different types available so you can choose the right one for your system.

Solar inverters convert the DC electricity your solar panels produce into the AC electricity that powers our everyday devices. If you thought all electricity was the same, you're certainly not alone, but let's back up a second:

• Direct current power flows in one direction. The voltage also remains constant. This allows it to be stored—so if you pair a battery with your solar panel system, the electricity it stores will be DC.

• Alternating current power is constantly switching direction. The voltage also fluctuates in a sinusoidal (basically a wave) pattern. So, AC electricity can more easily meet the power needs of all the various appliances throughout your home.

So, how exactly do inverters convert DC power to AC power? We don't want to bore you with the details, so we'll try to keep it pretty high-level.

1. When sunlight hits the solar cells that make up your solar panels, it generates DC electricity, which flows to connecting wires.

2. The wires connect the electricity to your system's inverter (or inverters depending on your setup).

3. The inverter contains a transformer, an electromagnetic device that changes the current's voltage level. 

4. Devices called transistors rapidly switch on and off. When the DC power reaches a transistor that’s off, it’s forced to change direction.The back-and-forth eventually "tricks" the DC power into becoming AC.

5. The AC electricity flows from the inverter to your house's electric panel. If you don't need that electricity, it will either go to the grid or your battery, if you have one. Either way, it’s primed and ready to power our everyday needs.

There are three types of solar inverter options to choose from: string inverters, microinverters, and power optimizers. (It’s important to note that power optimizers are used with string inverters.) All inverters work to convert DC solar energy into usable AC energy for your home, but each has a different method.

With many pros and cons to consider, you may have a hard time choosing which inverter option is best for you. As mentioned, a standalone string inverter typically makes the most sense if you have a sunny, fairly uncomplicated roof. (Think: minimal shading and less than 6 roof planes that would include solar panels.) If that’s not you, we’ll take some pressure off by saying there’s no universal right or wrong answer between a string inverter plus power optimizer setup and microinverters. We suggest talking to your installer to see what's best for your situation and needs.