Types of Solar Inverters
†††††There are three types of solar inverters, each used in different situations. A solar inverter is integral to the usage of solar panels because it converts the direct current (DC) from the sun into the usable alternating current (AC) power that is used for household appliances.
†††††1. Stand-Alone Inverter. Stand alone inverters are used in isolated systems such as cabins, cottages, water heaters, pumps, and monitoring stations. They are also used for mobile energy such as boats and RVs. The stand-alone inverter draws the DC energy taken from solar rays, from batteries and other sources such as wind turbines, hydro turbines, and engine generators. Many stand-alone inverters also incorporate battery charges to help replenish the battery from the AC source. These stand-alone inverters do not usually work with utility grids and are not required to have anti-islanding protection.
†††††2. Grid-Tie Inverter. A grid-tie inverter is an electrical device that allows users to complement their grid power with solar energy. The grid-tie inverter regulates the amount of voltage and the current that is received from the DC solar panels and then converts it into an alternating current. Grid-tie inverters make sure that the power will be in phase with the grid-power. This allows for selling excess power back to the power company. The meter must be able to run in both directions because of this. Grid-tie inverters do not provide power in the event of a power shortage. On the AC side, grid-tie inverters supply electricity in sinusoidal form (synchronized with the grid), and also limit feed in voltage no higher than the gridís voltage. On the DC side, the power outlet varies to find the maximum power point. These inverters use maximum power point tracking.
†††††3. Battery Backup Inverter. A battery backup inverter is a special inverter that draws energy from a battery, as well as manages the battery charge via an onboard charge, and also transfers the excess energy back to the utility grid. Battery backup inverters are required to have anti-islanding protection.
†††††These three types of solar inverters are very broad and may include other subsections within their types. It is important to use anti-islanding protection with the solar inverters for protection. When a utility company shuts off there are times when the circuits within resonate an electrical current that resembles an alternating current. The solar inverters may detect this current and continue to work even though the utility company is shut down. This is called islanding. It is very dangerous for utility workers who believe there are no currents because the power is off. An anti-islanding device injects impulses into the currents that offset the resonations, which causes the solar inverter to turn off completely, which eliminates danger to those working with the solar inverters.
†††††Each inverter is used in a different situation and they are easily interchangeable. If users decide to go off-grid or back on-grid, or even if they want to make a minor adjustment, it is easy to do so with the help of a different solar inverter.