A solar inverter is a device that converts the direct current (DC) electricity produced by solar panels into alternating current (AC) electricity, which is the form of electricity commonly used for household appliances and the electrical grid. In addition to converting the energy, solar inverters also optimize the photovoltaic production of the solar installation, allowing each solar panel to reach its maximum performance. In general, the inverter also has some safety and monitoring functions. It can stop production in case of a short circuit, grid failure, or component failure. Additionally, it collects production data, allowing to verify the correct operation of the installation and, if there is a problem, the opportunity to resolve it.
Grid-Tied Inverters (String Inverters): These are the most commonly used and economical solar inverters. In installations with string inverters, the solar panels are connected by strings or lines, requiring one inverter per line of solar panels. Therefore, the energy produced by each line is limited to the minimum power of each panel in the line. These inverters are mainly used in installations without shading and with panels that have very similar performance.
Each solar panel has its own microinverter, which converts the DC electricity produced by the individual panel into AC electricity. This configuration can optimize the production of each solar panel independently, making it a good option when there are shading issues or different types of panels in use.
Similar to microinverters, power optimizers are connected to each solar panel. However, instead of converting DC electricity to AC at the panel, they "condition" the DC electricity before sending it to a central inverter for conversion. Power optimizers combine some of the advantages of string inverters and microinverters.
Battery-Based Inverters or Off-Grid Inverters: These inverters are designed to draw energy from a battery, manage battery charging with a built-in charger, and supply power to AC loads. They are often used in standalone systems not connected to the grid, where the battery stores excess energy for use when the panels are not producing electricity, such as at night.
These inverters can handle inputs from both solar panels and a battery bank, charging the batteries with solar panels or the electric grid (depending on availability), and allowing the use of battery energy during power outages, for example.
The choice of inverter depends on several factors, including the installed power capacity, the location of the solar panels, the similarity of the panels, and the budget.
Finally, with regards to maintenance, most solar inverters require little to no regular maintenance. However, it's a good idea to monitor your system's performance to ensure it's functioning properly. Some inverters come with built-in monitoring systems, while others may require additional equipment. If you notice a significant drop in your system's production or if the inverter displays an error message, you should contact a professional for assistance. It's also a good idea to keep the area around your inverter clean and free of debris, and ensure it's not exposed to excessive heat or cold.
