Microgrid development in Puerto Rico: A shared point of focus and action that could work anywhere

One of the critical challenges of rebuilding Puerto Rico’s hurricane-ravaged electric system — beyond the tangle of physical, technical and financial logistics — has been formulating these visions and plans in the midst of shifting and at times conflicting political forces. Gov. Ricardo Roselló’s recent proposal to restructure the island’s public utility, the Puerto Rico Electric Power Authority (PREPA), coupled with the utility’s ongoing financial problems, continues to fuel uncertainty. The role and status of the Puerto Rico Energy Commission (PREC) also remains in flux.

SEPA CEO Julia Hamm shot this video of damage to Puerto Rico’s electric system during a visit to the island in December. 

With so much unsettled, the potential deployment of microgrids has emerged as a shared point of focus — and action — both for immediate power restoration at critical facilities and in remote communities, and for more long-term plans for a modern, clean and resilient grid.

For example, a section on microgrids was a core part of Build Back Better, the report authored by the Puerto Rico Energy Resiliency Working Group, a consortium of U.S. and Puerto Rican energy groups, including the Smart Electric Power Alliance (SEPA). A month later, PREC issued draft regulations aimed at setting up standards for microgrid deployment on the island. The proposed rules incorporated many of the concepts from the Build Back Better report.

Meanwhile, U.S. solar and storage companies, utilities and other groups are already on the ground, partnering with Puerto Rican organizations to provide emergency power to fire stations and other critical facilities.

The catch here is that this forward momentum is occurring at a time when a unified plan for restoring Puerto Rico’s energy system is far from complete, with no one “right” approach decided. In the interim, what is needed is a clear, consistent and transparent process for expanding and scaling microgrid deployment across the island.

Based on SEPA’s work on Build Back Better and our subsequent research in Puerto Rico and elsewhere, we offer the following recommendations. Our goal here is not to suggest one right or narrow path forward, but rather a general structure that can be used as a roadmap for microgrid development not only in Puerto Rico, but anywhere.

Stakeholder engagement

Any plan for microgrid and other DER deployment must be built on consistent, ongoing and broad stakeholder engagement. The conditions in Puerto Rico underline just how important having a full range of views and voices can be. Specifically, the Governor’s Office, the Financial Oversight and Management Board of Puerto Rico, PREPA, and PREC will be essential participants, as will first responders, health care facilities, business and representatives from remote communities.

Local officials and other community members can be extremely valuable in identifying potential sites for microgrids, where in-depth data and firsthand knowledge of these locations will be critical. (See Site Identification section below.) The same level of engagement and data analysis will also be needed for the more long-term planning that will undoubtedly continue across hurricane seasons in coming years.

Holistic, coordinated planning

Determining microgrid deployment priorities will necessarily encompass a range of planning functions, such as investment strategies and system management decisions. The Governor’s Office of Puerto Rico included $1 billion for microgrids at critical facilities as part of its $94.4 billion request to the U.S. Congress for emergency rebuilding funds. Such DER investments should be planned in close coordination with PREPA’s integrated resource plan (IRP) to avoid duplicate or redundant investments, while also optimizing system reliability.

This level of coordination is essential for gauging the impact of future DER deployment strategies on the surrounding configuration of the grid, and vice versa. Investments in system-wide control technologies will be needed both to improve reliability and enable the grid to properly handle more interconnected loads and DERs. Options here might include distribution supervisory control and acquisition (D-SCADA) systems, distributed energy resource management systems (DERMS) and distribution management systems (DMS). In particular, investments in systems for microgrid operation and communication will have to be incorporated into PREPA’s IRP, while again avoiding duplication or redundancy.

Process, transparency and ownership options

DER deployment strategies — from site selection and permitting to interconnection and dispatch — must also include open and transparent processes to allow for customer, third-party, and PREPA or other utility ownership. The solar industry’s response to Maria has already introduced different ownership models. In the weeks following the hurricane, SunRun and partner organizations installed a solar plus storage system at the Barrio Obrero fire station in San Juan, and other companies are working to install similar systems.

PREC’s proposed regulation on microgrid permitting and deployment is a step toward the development of these kinds of basic, but essential processes. The current comment period for the regulation ends Feb. 5, providing a critical opportunity for PREPA, third-party solution providers and other stakeholders to ensure their voices are heard in the rule-making. Significant issues to be addressed here include defining the roles of utilities, customers, third-parties and regulators, and the more complex standards covering microgrid and other DER operation, rates, fees, and interconnection requirements for the different ownership structures.

Site identification

Again, in-depth stakeholder engagement will be critical for identifying the communities or other locations where microgrids will be built, and the specific generating capacity or other functions they will include. The 159 microgrid locations recommended in the Build Back Better report provide a high-level overview of the investments needed to bolster critical facilities, in particular for post-disaster recovery. The potential exists for many more microgrids across Puerto Rico, providing additional benefits to customers, communities and the island as a whole. In a separate effort, the U.S. Department of Energy identified 200 locations where microgrids totaling more than 11 megawatts might be sited, not only for critical facilities, but also for commercial and industrial users.

Data from stakeholders — including PREPA, PREC, third parties and customers — will also play a integral role in determining the functions and value of individual microgrid systems. Analysis of available data can help define the energy needs of critical facilities, the hosting capacity of the local feeders connecting these facilities to the distribution system, and the system-wide conditions further shaping the types and sizes of DERs to be deployed.

For example, leveraging existing solar or other distributed generation, such as combined heat and power, could allow further integration of renewables at a specific site, while constrained hosting capacity at a substation could limit a microgrid’s size and generating capacity. Due diligence on specific sites might include the potential logistics of site preparation — such as grading or access to other infrastructure — and interconnection and permitting requirements

The needs of dense urban populations must also be balanced with the severe access restrictions found in remote communities. Surveys of rural and remote parts of the island will be needed to determine optimal siting for installations, based on terrain, distance from existing or planned generation, and the extent of damage to electricity lines.

Deploying for highest value

Part of the value proposition of microgrids is their flexibility and scalability. They can provide power, emergency back-up, and grid support for large-scale commercial and industrial parks, critical facilities, and off-grid remote communities. These applications may each incorporate different technologies, and deliver different economic or resiliency benefits. The specific DERs used in a microgrid may determine the length of time the system can “island” itself, operating independently from the grid.

Thus, the planning process should include a review of potential applications, and aim for deployments that bring the highest value and resilience for customers and the grid. Here again, a holistic approach is required. For example, analysis of potential microgrid sites might include an overlay of nearby load centers and distribution substations to determine if a larger community system makes more sense — and might provide more resilience — than smaller installations at multiple locations.

A platform for the future

While growing out of SEPA’s work in Puerto Rico, these recommendations, and the process they define, can be used as a starting point for microgrid development at almost any location. The flexibility they provide allows for local customization at each stage of microgrid deployment, from data analysis to regulatory approval.

The Puerto Rican experience thus far also provides a case study for microgrid development as a platform for building collaborative relationships across industry and stakeholder communities. The partnerships and closer working relationships forged in response to the emergency conditions in Puerto Rico will hopefully be a catalyst for ongoing communication, engagement and innovation as the future visions and plans for the island’s energy system continue to unfold.

Interested in microgrids? SEPA has a Microgrid Working Group. See also Microgrids: Expanding Applications, Implementations, and Business Structures, a report co-authored by SEPA and the Electric Power Research Institute.