Distributed Energy Storage System is a new energy power solution which can be used grid interactive and stand alone. An integrated ultra-fast AC transfer switch guarantees that even sensitive back-up loads, like computers, never know when a utility outage occurs. The bi-directional inverter can provide high quality true sine waveform power for the load. The working mode of the DESS can be selected and adjusted to meet different requirements. The systems are sized for 30 Kwh to 4 Mwh, which is shown in its transportable container above.