What are Micro-Inverters?

If you’ve been doing research on solar panels or have been considering a solar installation for your home, you may have run across different types of inverters. In this article, you’ll learn about micro-inverters and how do they give your solar panels an advantage over normal inverters, known as “string” inverters. 

To start with, let me quickly cover what an inverter is and does:

An inverter is one of the most important parts of a solar panel system. When solar panels generate electricity, they generate direct current electricity. However, your home uses alternating current. An inverter is a small device that changes the direct current electricity produced by your solar panels, into alternating current for your home to use. 

Now let’s look at a potential scenario and how micro-inverters work compared to string-inverters.

Your new solar system is installed and the sun is shining, but your solar panels aren’t producing as much electricity as you thought they would. 

That’s definitely a problem you want to avoid!

The solar panels we use at Expert Solar use micro-inverters to solve that problem.

To start with let’s quickly examine the opposite end of the coin – string-inverters. String-inverters are the most common kind of inverter used on solar panel systems.

The quickest way to explain string inverters is by saying “Christmas lights”. 

As described above, when solar panels convert sunlight into electricity the end result is direct current. Because homes use alternating current, solar power systems use inverters to convert the direct current produced by solar panels into alternating current that your home can use. 

Solar panels that use string-inverters essentially work as a network of panels, converting sunshine into electricity. The first panel is connected to the second panel and so on. The direct current electricity is passed through wires that go through each panel and are finally converted to alternating current by a single inverter at the end of the chain. 

In the case of string-inverters, electricity passes from one solar panel to the next. All the electricity is then funneled into one inverter that feeds electricity into your home. 

In a string of Christmas lights, each light depends on the prior light in order to receive an electrical flow. If one light breaks, all the lights that come after that one light will not work. 

While solar panels that use string-inverters are not quite as dramatic, if somewhere along the line a solar panel fails to produce well, be it faulty or in the shade, it affects the overall electricity production. 

Additionally, it’s hard to determine which solar panels aren’t producing. 

That was solar panels up until the early-mid ’90s. Unfortunately, a lot of installers still use solar panels with string-inverters. 

As we’ve stated time and time again in our blogs, thanks to continued advancements in solar technology, today solar panels are more efficient and effective than ever before. 

One of the major advancements that have made solar panels more effective is micro-inverters, which are used on all Enphase solar panels.

So, what is a micro-inverter?

Micro-inverters are small inverters that are attached to every single solar panel. In a micro-inverter system, each panel produces its own electricity, converts it from direct current to alternating current, and then passes it to your home to use. 

If one solar panel happens to be in the shade for part of the day or is faulty for some reason, your home still gets plenty of electricity as that one solar panel will not impact the entire system. 

And, with micro-inverters, if a solar panel isn’t producing enough electricity, we know exactly which solar panel needs to be moved, fixed, or replaced. 

All Enphase solar power systems we install come with an app that not only helps you see the performance of your individual solar panels and the entire solar power system but if any single solar panel is not performing well we, the installers, receive an alert as well. 

Are Micro-Inverters More Effective Than String-Inverters?

Some companies that still produce solar panels that work with string-inverter systems are able to sell their solar panels at a slightly lower cost than more advanced solar panels that use micro-inverters. 

However, most people will argue that the slight difference in price is worth the better value and electricity production over time. It’s also been proven that micro-inverters provide better overall performance and output, and are more reliable. 

Simply put, solar power systems that use micro-inverters produce more electricity than those that use string-inverters. 

Here is a quick video that we found, that helps to describe how Enphase micro-inverters work. We did not produce this video but we think it does a great job at depicting how micro-inverters function. 

Ricardo Del SolArticle by
Ricardo Del Sol
Editor, Expert Solar
(800) 340-0681