An inverter is a key component of a solar power system. Also known as a PV inverter, its primary function is to convert direct current (DC) electricity into alternating current (AC) electricity. Without an inverter, the average homeowner wouldn’t be able to use any solar power generated by his or her solar panels.
Solar Power Inverters: The Basics
When a photovoltaic (PV) solar panel receives sunlight, it creates DC electricity. Our homes here in the U.S., however, use AC electricity so, solar power systems require an inverter to create usable electricity. The inverter takes the DC electricity generated by the solar panels and converts it to AC electricity.
Some solar power inverters do more than just basic DC-to-AC conversion. While this is their primary task, some of the advanced models also act as the “brains” of the system. For instance, they can provide data reports on the system’s functionality as well as utility controls. Owners can use the advanced inverters to optimize their solar power system for maximum efficiency.
There are several different types of solar power inverters in use today:
A string inverter is a type of power inverter that’s attached to a row of solar panels. Each row is given its own dedicated string inverter. While efficient, string inverters typically perform poorly in shaded environments.
Another type of solar power inverter is the central inverter. They are larger and more complex than their string counterpart and may have a high price tag. However, they can support more solar panels, making them a smart investment for large-scale power projects.
Perhaps the most popular type of solar power inverter for residential use is the micro-inverter. Significantly smaller than string or central inverters, they are installed directly on the solar panel. Micro-inverters perform the DC-to-AC conversion at the panel level.
Additionally, micro-inverters are capable of monitoring the performance of the panel to which it’s attached. The largest benefit to a micro-inverter is that when one or many of your panels have shade, only those panels lose productivity, not the entire row of panels as is the case with string inverters.
What’s Wrong with DC?
Of course, this begs the question: why can’t we just use DC in our homes? The U.S. Department of Energy (DOE) explains that DC was once the standard current technology used in the United States. The problem with DC, however, is that conversion to lower and higher voltages is difficult. This prompted Nikola Tesla to develop AC electricity.
Today, AC remains the standard current on which we run electric devices and systems. This doesn’t necessarily mean that DC has been eliminated. It’s still used for electric vehicles and a few other applications. But AC is now the de-facto standard for most electric devices and systems.