The Various Types of Solar Inverters and Their Functions
Solar power is becoming more popular for meeting residential, and business power needs thanks to improved technology and the decreasing cost of solar equipment. As a result, many homeowners can afford to install a modest solar array to offset the use of grid power, which can lower utility bills and provide a clean source of environmentally friendly green energy. While many think of the visible solar panels first when considering solar power, the real heart of the solar power system is the solar inverter.
The solar inverter in the home solar power system is charged with converting the direct current (DC), energy captured by the photovoltaic panel into alternating current (AC), a power that can be used by your household electrical system. Home solar inverters come in a variety of types, which includes string inverters, microinverters, and string inverters with power optimizers. While all inverters perform a similar function, the mechanics of each differ, creating a diversity of options for those who wish to power their homes with solar. You can buy solar inverters for single-phase power, or you can purchase 3-phase solar inverters. Regardless of your needs, there is a solar inverter that can meet them. Keep reading to learn more about the types of solar inverters and what each one does.
String inverters are the most common type of inverter in use today because they are the most affordable and simplest to install. Modern day versions have multiple independent inputs (MPPT’s) allowing for multiple strings of panels with different quantities, types and direction of panels. A string inverter, as the name would indicate, is an inverter that is attached to a string of panels. For example, if you have 22 panels in your array, you may have 10 panels facing south connected to one input and twelve facing west connected to a second input. If there are shading issues on the roof at certain times of the day, optimizers can be used in conjunction with the string inverter to ensure all day maximum efficiency. Depending on the NEC codes applicable to the installation, Rapid Shutdown requirements may be required during the installation. This can be achieved by string level rapid shutdown devices (NEC 2014) or module level rapid shutdown devices (NEC 2017).
Microinverters offer another way of handling the power generated by photovoltaic panels. Instead of one inverter serving a string of panels, microinverters are installed on each panel in an array. The current generated by the panels is converted to AC power on the roof, which means no central inverter is needed. They are more expensive than string inverters, but they provide some benefits that over a string inverter. Multiple types of panels can be used in a single array with microinverters, shading and orientation becomes irrelevant and adding additional panels at a late date is easily accommodated. Module level monitoring is also a benefit, where the installer and homeowner can monitor the performance of each panel and microinverter.
Power optimizers are much like microinverters, but the primary difference is that they have a lower price point. As is the case with a microinverter, each panel has its own power optimizer. However, unlike a microinverter, the power generated from the panel isn’t converted from DC to AC on the roof. Instead, the current is relayed by the power optimizer to a string inverter which provides the AC.
Though the photovoltaic panels are the most visible component of your solar power system, it’s the inverters that make that power available to your home in a usable form. Though all three types of inverters provide the same service, the way they go about it differs dramatically. To learn more about the types of solar inverters and what they do, contact The Power Store at (888) 595-0580.