A solar inverter converts the direct current (DC) electricity that solar panels produce into alternating current (AC), the kind of electricity used by home appliances and the power grid. It does this by switching the DC input back and forth very rapidly, and filters shape the output into a clean sine wave the grid can accept.
In a home system, the inverter usually also monitors how much the panels are producing and communicates that data over a network. In solar-plus-battery systems, advanced inverters can keep the home powered without grid support during an outage, if the system is designed to do so.
Source: U.S. Department of Energy: Solar Integration: Inverters and Grid Services Basics.
Image: Tesla Solar Inverter and AC disconnect, by RickyCourtney, CC BY-SA 4.0, via Wikimedia Commons.
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