The approval follows completion of four years of extensive environmental assessment for the proposed offshore FLNG project, known as Aguirre Offshore GasPort.
The terminal comprises a floating storage and regasification unit (FSRU), minimal infrastructure to moor the vessel, and a subsea pipeline to facilitate gas supply onshore.
Puerto Rico Electric Power Authority (PREPA) will use the fuel from the FLNG for its Central Aguirre Power Complex, Excelerate said.
PREPA interim executive director Carlos Castro said: "This project is critical for PREPA to reduce the cost of energy in Puerto Rico and to reduce the emission of air pollutants."
Excelerate along with FERC and cooperating agencies will work together in the coming months to begin construction of the project scheduled in the first quarter of 2016.
The terminal is scheduled to be commissioned in the second quarter of 2017.
