# Energy Storage AC Cabinet AC storage cabinets integrating PCS, STS, transformer and protection — pre-assembled, fast grid/island switching. The AC storage cabinet integrates the PCS, the static transfer switch, a step-up transformer and the protection & metering units into one factory-pre-assembled enclosure. On site you only terminate the AC cables — the grid/island transfer logic is already configured inside, and several cabinets can be paralleled for larger projects. It is the fastest path from order to energised asset.