As Puerto Rico begins modernizing its storm-battered power grid with small-scale energy storage and microgrid systems, authorities on the island are betting on large-scale batteries as well.
Through a recently issued request for qualifications, Puerto Rico and the government-owned Puerto Rico Electric Power Authority, or PREPA, are seeking to partner with private developers on utility-scale energy storage, beginning with an initial 20-MW/20-MWh system in 2019. In addition to designing the battery-based energy storage project with "flexibility and modularity" to expand to 40 MW/160 MWh, Puerto Rico asked developers to provide "options for future deployment of [an] additional four projects" in that same size range.
PREPA plans to release a formal request for proposals after compiling a shortlist of qualified bidders in August. The winning bidder would be required to supply a minimum 20-MW/20-MWh system no later than the second quarter of 2019. The developer would operate the system under a long-term contract, according to the request, while PREPA would maintain responsibility for "the required charging."
Sited at "strategically located transmission centers," Puerto Rico's possible future fleet of large-scale energy storage systems would provide numerous services, including frequency regulation, voltage regulation, integration of intermittent renewables and operation during system blackouts.
The request, issued June 22, came after the Puerto Rico Public-Private Partnerships Authority in May published a study on large-scale energy storage that resulted from an unsolicited proposal by Tesla Inc. to replace peaker plants with battery energy storage systems. The study concluded that procuring energy storage through a long-term contract with a private developer "would shift the appropriate risks to the private sector and achieve the needs and objectives of Puerto Rico."