What Is a Solar Inverter?

Understanding the solar Inverter

A solar inverter is one of the most important devices in a solar system. It is a device that converts the direct current (DC) electricity generated by solar panels into alternating current (AC) electricity that can be used in the grid. In DC, electricity maintains a constant voltage in one direction. In AC, as the voltage changes from positive to negative, the current flows in both directions in the circuit. Solar inverters are just one example of power electronic devices used to regulate the flow of power.

Fundamentally, solar power inverters accomplish the DC-to-AC conversion by rapidly switching the direction of the DC input back and forth. As a result, the DC input becomes an AC output. Additionally, filters and other electronic devices can be used to generate clean, repetitive sinusoidal wave voltages that can be injected into the grid. A sinusoidal wave is a shape or pattern of voltage that is formed over time and it is a power pattern that the grid is designed to operate at specific frequencies and voltages without damaging electrical devices.

The first inverter was created in the 19th century and was mechanical in nature. For example, a rotating motor would be used to continuously switch DC power forward or backward. Today, we use electronic switches, made with transistor technology, which are solid-state devices without moving parts. Transistors are made with semiconductor materials such as silicon or gallium arsenide, and they control current in response to external electrical signals.

Understanding the residential solar inverter

If you have a residential solar system, your solar inverter may perform multiple functions. In addition to converting solar energy to AC power, it can also monitor the system and provide a portal for communication with computer networks. Solar battery storage systems rely on advanced solar inverters to operate in the event of a power outage, if they are designed to do so.

As more solar systems are added to the grid, there are more inverters connected to the grid than ever before. Inverter-based generation can produce energy at any frequency and does not have the same inertial characteristics as steam-based generation since there are no turbines involved. As a result, transitioning to a grid with more solar inverters requires building smarter inverters that can address frequency changes and other disruptions that may occur during grid operation and help stabilize the grid against these disruptions.