A string inverter is a device used in solar energy systems to convert the direct current (DC) generated by solar panels into alternating current (AC), which can be used in homes and businesses. It connects multiple solar panels in a series, or "string," allowing them to work together efficiently. String inverters are popular due to their simplicity and cost-effectiveness. They are typically installed on rooftops or near the solar panel array, making them easy to access for maintenance. However, their performance can be affected by shading or dirt on one panel, which can reduce the overall energy output of the entire string.