To the casual observer, one solar panel looks as good as the next. But looks can be deceiving. 

Solar panels are those mysterious-looking pieces of hardware installed on rooftops of homes and offices that make it possible to convert sunlight into electricity. 

In the past, solar panels had a clunky effect that ruined the aesthetics of your roof. However, thanks to technological advancements, many solar panels are sleek in design and can efficiently generate enough electricity to meet your energy needs. 

As of 2021, more than half the residential solar panels installed in the US had efficiency ratings above 20%, compared with 0.6% a decade ago, according to the Lawrence Berkeley National Laboratory's Tracking the Sun report.

Understanding the different types of panels and how to choose between them can be confusing. Here's what you need to know.