Puerto Rico is an island that lacks any indigenous gas reserves. As a result, it is entirely dependent on LNG imports for its gas supply. Imports commenced in July 2000 with the commissioning of the country's first LNG regas facility, Penuelas, on the southern coast. Puerto Rico has over 5,000 MW of installed power capacity, the majority of which is oil-fired. The long-term potential market for gas relies almost entirely on the power sector. Currently, Aguirre 1&2 steam turbines (ST), Costa Sur 3&4 and Palo Seco power plants, which runs on no. 6 fuel oil, do not comply with MATS. Consequently, PREPA should convert these units to natural gas to continue its regular operations, or alternatively, retire or declare them as limited use. Due to the low reserve margin required to supply Puerto Rican electricity demand, PREPA is switching to gas at its power plants.