Microinverter
A small inverter mounted behind an individual solar module that converts that module's DC output directly to grid-frequency AC. Modules are then connected in parallel on an AC trunk cable instead of being wired into a DC string.
Because each module has its own converter and its own MPPT, shading, soiling and mismatch are contained to the affected panel, and there is no high-voltage DC wiring on the roof at all, which satisfies rapid shutdown by construction. Microinverters suit complex roofs with several orientations and allow a system to be expanded one module at a time. The counterarguments are cost per watt, a larger number of units to fail, and the fact that any failure is on the roof rather than at ground level. Units are typically rated for a few hundred watts each, matched to a single module.