Solar rapid shutdown: why modern systems have electronics under the panels
An electrical-code requirement that rooftop solar can be de-energised quickly so firefighters can work safely. It is why most U.S. systems use microinverters or optimizers.
Since the 2017 and 2020 editions of the National Electrical Code, rooftop systems must reduce voltage on the roof to safe levels within seconds when shut down. The simplest way to comply is electronics at each panel: microinverters or optimizers.
This narrowed the price gap between string inverters and module-level electronics, and gave most homes panel-by-panel monitoring as a side effect.
What this means for you: You don’t need to choose a rapid-shutdown method yourself, but confirm the quote includes code-compliant equipment and that the price covers it.