The Montauk a 5 MW/40 MWh BESS, consisting of three (3) lithium ion battery systems located in an architecturally pleasing battery building with three (3) 2.2 MVA inverters. The Montauk BESS was conceptualized alongside the East Hampton BESS (which ECI also designed) due to soaring electric demand and a need for improved system reliability in the East Hampton area. ECI was responsible for all civil, electrical, mechanical and architectural design, from battery strings to the interconnection to 13.2 kV distribution. ECI’s distribution design included ground-breaking considerations due to extremely high energy capacity at inverter DC terminals.