IREC, Local Partners Support New Microgrid Project in Castañer, Puerto Rico
(Castañer, June 2, 2022) — The rural community of Castañer, Puerto Rico celebrated the first phase of a solar-plus-storage microgrid installation that will provide continuous and reliable electricity to power local businesses and essential services. The project includes two electric vehicle recharging stations, the first to be installed in the central mountain region of Puerto Rico.
The microgrid was developed in a collaborative process led by the Puerto Rican Solar Business Accelerator (PRSBA), along with the nonprofit Cooperativa Hidroeléctrica de la Montaña and the University of Puerto Rico — Mayagüez. The PRSBA is a program led by the Interstate Renewable Energy Council (IREC) and Pathstone Corp. and funded by the U.S. Economic Development Administration.

The first phase of the microgrid will power local businesses including a bakery, ice cream shop, barber, post office, community center, and two electric vehicle charging stations, totaling 40 kW of solar PV and 35 kWh in battery storage. Small businesses constitute the backbone of economic activity in rural and remote villages in Puerto Rico, and can support active community life when they continue operation during and after extended power outages. When the next phases are added, the complete microgrid will include approximately 225 kW in solar PV and 500 kWh in battery storage. Installation and development of the microgrid was led by a local solar company Borintek.
Castañer is located in an isolated area between the towns of Adjuntas, Lares, Maricao, and Yauco, which endured more than six months without power after Hurricane Maria in 2017. The first phase of the microgrid is designed with the goal to provide uninterrupted electric power services during future emergencies. The first real-world test was successful: The microgrid continued to provide electricity to the businesses when a fire at a power plant caused a massive island-wide blackout in April 2022.
“After several months of work with the Cooperativa Hidroeléctrica de la Montaña and the University of Puerto Rico, we can see the result of our collaboration in the well-being of the Castañer community. This microgrid is the first of many great projects that are coming up in rural Puerto Rico,” said Loraima Jaramillo Nieves, program manager at IREC.

“I visited the town of Castañer several times after Hurricane Maria, and I could see how the businesses made numerous efforts to maintain services in the community. The residents were plunged into darkness for more than six months. The lack of electricity affected their quality of life since they could no longer attend to food and medicine needs. This is what motivated us to launch, through the Cooperativa Hidroeléctrica de la Montaña, our first Resiliencia Energética Fotovoltaica Comunitaria (ReEnFoCo) project through the Castañer microgrid,” said Maribel Hernández, assistant manager of the project.
For her part, Sonia Sánchez, owner of the ice cream shop Machete en Mano, said she returned to Castañer to establish her business and enjoy the peaceful community. The frequent power outages in Castañer have led to business losses since everything must be refrigerated, and in many cases they have been forced to discard all merchandise. “We are very happy with this Castañer microgrid because we can offer our products, be ready when the community needs energy for its medical needs, and are able to move forward,” she said.
This is the first of two microgrids that will be developed with the support of the PRSBA. The second will be in Maricao and will incorporate restaurants, a medical clinic, and other businesses and services. The Castañer event was attended by the mayor of Adjuntas, José H. Soto Rivera, and the mayor of Lares, Fabian Arroyo Rodríguez, who both supported the development of this microgrid.
About IREC
IREC builds the foundation for rapid adoption of clean energy and energy efficiency to benefit people, the economy, and our planet. Its vision is a 100% clean energy future that is reliable, resilient, and equitable. IREC develops and advances the regulatory reforms, technical standards, and workforce solutions needed to enable the streamlined integration of clean, distributed energy resources. IREC has been trusted for its independent clean energy expertise for nearly 40 years, since its founding in 1982. For more information, visit www.irecusa.org or follow IREC on Twitter, LinkedIn, or Facebook.