Cooperating to Create Resiliency for Castañer: Plan Calls for Networking DERS and Community Microgrids for Puerto Rican Town

To solve resilience challenges, it’s critical that stakeholders, decision-makers, government institutions and a diverse group of community members participate in developing plans, said the plan. The Castañer Energy Resilience Plan (CERP) is an example of this process, the plan said.

As part of the effort, community members identified residents and critical community services that need resilient energy, said Carlos Alberto Velázquez, program director, IREC. That included  22 homes with people who are bedridden, have limited mobility or who have medical devices. The idea is to provide solar and storage to these people, possibly under power purchase agreements (PPA), which don’t require up-front investments. First, it’s important to determine whether the roofs on the homes are structurally sound enough to hold solar systems, said  Velázquez.

The team that developed the plan also identified a shelter and nearby critical services in the town as a candidate for a resilience hub.

It’s possible that the community will also meet the needs of the agricultural sector–which focuses on producing coffee, vanilla and cocoa–with PPAs, he said.

Two multi-facility microgrids are already operating in town

Right now, the town has two multi-facility microgrids–one with 45 kW solar and 95 kWh storage that was completed in the summer of 2022–and another, completed in the summer of 2023, with 75 kW solar and 150 kWh storage. The two microgrids could be ultimately networked together.  Velázquez said the microgrids are located in the town square, and serve essential businesses such as a bakery, mini-mart and postal service station, along with a few homes that are located next to the businesses. The microgrids are separate because the areas they serve aren’t close enough to one another to create a single microgrid.

The first microgrid was developed by IREC and Cooperativa Hidroeléctrica de la Montaña, and is the first solar microgrid in Puerto Rico that serves a group of businesses, said the report.

Microgrid provided resilience after Hurricane Fiona

After Hurricane Fiona struck Puerto Rico in September 2022, that microgrid kept electricity flowing in Castañer while the rest of the community was without power for 3 to 5 weeks,Velázquez said.

Funding for the Castañer Community Energy Resilience Plan came from the U.S. Department of Energy’s (DOE) Renewables Accelerating Community Energy Resilience program, in the amount of $156,000.

About $400,000 in funds for the two existing multi-facility microgrids came from the U.S. Economic Development Administration and were built as part of an IREC Puerto Rico solar business accelerator. The accelerator focuses on microgrid pilot programs that serve essential businesses in disadvantaged communities.   The program has a $3 million, 3-year budget, said Velázquez.

Other distributed energy resources could be networked

The two microgrids aren’t the only candidates for networking. Also located in the town are a restaurant with 11 kW of solar and 18 kWh of energy storage, plus a community hospital with 213 kW solar and 928 kWh storage, he said. The town’s school has a 50-KW independent solar system.

“The whole idea is to network everything,” Velázquez said. “Eventually because there are so many distributed solar and storage assets in that area, the vision is to come up with a microgrid controller that could control and network the assets, a network in the clouds or a physical network.”

To achieve that goal–hopefully in 3 to 5 years– the team of community members wants to design, test and deploy an automated sensing and communications system that integrates the DERs in the community, according to the plan. This open source platform would centralize the town’s energy data and optimize DER operations in real time, said the plan.

The plan offers more than a dozen recommendations, including calling for Luma Energy to modernize the infrastructure. But these are just recommendations, said Velázquez. Hardening the grid by installing poles that can withstand winds of up to 165 miles per hour is one of the grid hardening recommendations for Luma. The plan also calls for deploying modern technology to better automate operations, he said. Right now, Luma workers have to visually identify areas that need to be repaired, tracking miles of distribution lines in complicated terrain. An automated system would save time and resources, he said.

DOE provided $450 million for residential solar and storage

The number of solar and storage projects in Puerto Rico is expected to grow. In August 2023, the DOE released more than $450 million to fund residential solar and storage installations. The program will focus on projects across Puerto Rico, particularly the most vulnerable residents there.

In addition to the deployments in Castañer, microgrids are beginning to bring some much-needed resilience to Puerto Rico, whose grid was destroyed after Hurricane Maria. When Maria hit the U.S. territory on September 20, 2017, 100% of the 1.57 million accounts served by the Puerto Rico Electric Power Authority, the island’s utility, were without power.

After Hurricane Fiona knocked out power in September 2022, a fire station and 45 residents on the island of Culebra benefited from power supplied by microgrids — and shared the wealth with their neighbors.

Working hand-in-hand with neighbors is also an important focus for the Castañer community.

“This project is not just about building and installing solar and storage, it’s about engaging in a community dialogue where people identify the most critical needs and vulnerable citizens,” said Velázquez.