The Puerto Rico Electric Power Authority (PREPA) filed the latest edition of its 2019-2038 integrated resource plan which calls for 1,800 megawatts of solar, 920 megawatts of storage and resilient MiniGrids at a cost of about $14 billion, according to a June 7 testimony and plan.

With the assistance of Siemens and extensive stakeholder input, PREPA settled on a plan for a highly distributed system of flexible generation and so-called MiniGrids, in combination with hardening of transmission infrastructure. According to the plan, the utility wants to break down the territory’s system into eight largely self-sufficient electric islands that can operate individually in the case of a major storm like hurricane Maria, which in 2017 left more than 1.5 million residents without power for months.

As for generation, Siemens recommends that PREPA should issue a request for proposals for solar photovoltaic in blocks of approximately 250 megawatts, with the goal of adding 1,380 megawatts over the first four years. The plan also includes the installation of 920 megawatts of battery energy storage in the first four years, to be developed alongside the solar additions in blocks of 150 to 200 megawatts. These targets are even bolder than the utility’s already ambitious previous plan of up to 1,200 megawatts of solar and up to 900 megawatts of energy storage. The plan also calls retiring older oil power plants units and modernizing the remaining ones to use natural gas. Finally, it notes the potential of energy efficiency and demand response measures to help the utility adapt to future load, which remains uncertain given the island’s population and economic outlook.

If the plan is successfully implemented, it will slash Puerto Rico’s emissions by at least 81 percent and put the island on a path to reaching its goal of 100 percent renewable energy by 2050.

The utility submitted a revised integrated resource plan back in February, ahead of the March 2020 schedule, to reflect changes in demand and generation as a result of hurricanes Irma and Maria, which devastated the island’s power grid. The commission determined the need to update the 20-year resource plan before the mandatory three-year review date to assess any effects from the hurricanes on the island’s electric market.