Anti-islanding
By Priya Nair · Last reviewed A mandatory protection that makes a grid-tie inverter stop exporting power within roughly two seconds of losing the utility grid reference. It prevents a solar system from energizing a de-energized line — protecting utility workers — and de-energizes the plug pins of a plug-in system almost immediately after disconnection.
Why it matters
Anti-islanding is why compliant plug-in solar is shock-safe at the plug and why every grid-tied system goes dark during a blackout. It is a certification requirement under IEEE 1547 (implemented via UL 1741 in the US and G98/VDE rules in Europe), not an optional feature.