Client: U.S. Naval Facilities Engineering Command Far East
Location: Diego Garcia, British Indian Ocean Territory
To reduce its reliance on fossil fuels, the U.S. Navy planned a 3 MW solar farm to help power the remote island of Diego Garcia. But there were a few challenges that would need to be solved first.
Specifically, the existing distribution infrastructure was not designed for two-way power flow and the power control system would need to be replaced. The Navy asked us to conduct distribution planning studies and a design charrette.
To identify the connection point of the solar facility’s 13.8 kV feeder to the Navy’s distribution grid, we needed to build a PSS/E distribution system model. The model required a complete on-site data collection effort to field-verify existing facility and geotechnical information.
The planning effort also supported the design of a 500 kW, lithium-ion battery energy storage system (BESS) that allows the battery to be used if clouds and rain affect the solar plant output. The battery system was designed to discharge up to 1 MW of power in 30 minutes.
This distributed energy resources (DER) project is just one of many that have been launched by the U.S. Department of Defense—the nation’s largest energy user—to decrease fossil fuel use through improved energy efficiency and a pivot to renewable energy sources.
- Energy security: Solar power with battery storage allows operations to recover more rapidly from power disruptions, contributing to the Navy’s mission assurance.
- Met renewables goal: Diego Garcia will help the Navy meet* mandatory renewable energy goals and reduce reliance on expensive fossil fuels which had to be shipped to the remote island.
Solar Project Features
- 13-acre solar field
- Two 1,560 kW inverters
- 3 MVA transformer
- 500 kW, lithium-ion Battery Energy Storage System
- Fiber communication cable between battery room and solar farm
- 8 kV underground feeder
*Project is currently under construction. Completion planned for 3rd quarter 2021.