SEL, Puget Sound Energy Collaborate With Customers for Community Microgrid

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Puget Sound Energy (PSE) and SEL have completed a joint microgrid project on Samish Island, Washington. The system provides reliable backup power for the community fire station, operating seamlessly during five islanding events in its first storm season.

Samish Island connects to the main power grid with a single distribution line maintained by PSE. During storm seasons, the community and volunteer fire station—serving nearly 500 households—experienced frequent outages that impacted emergency response times. PSE determined a microgrid could maintain service during disruptions. When a resident suggested using rooftop solar power from nearby homes, PSE agreed this solution would be ideal to charge the microgrid battery. The utility turned to SEL Engineering Services to help create a microgrid control system that provides continuous power availability during outages.

PSE installed the microgrid, which includes a battery energy storage system, solar generation from three homes and an 8 kW ground-mounted solar array at the fire station. SEL Engineering Services designed and implemented the microgrid controller using the SEL powerMAX Power Management and Control System built around an SEL-3555 Real-Time Automation Controller (RTAC). The RTAC coordinates all system elements, continuously monitors the grid connection and manages system load and battery status.

“We landed on using the SEL RTAC solution as the microgrid controller because it speaks a plethora of communication languages, and it’s a secure OT device that integrates well with our security requirements,” said Ben Barr, PSE integration engineer.

When a fault occurs on the main line, an SEL-651R Advanced Recloser Control trips the PSE recloser at the point of common coupling. The RTAC then islands the homes and fire station, allowing the microgrid to operate independently and maintain real-time load balance. Stored energy powers the fire station, while solar continually charges the battery. A mass notification system sends email and text alerts to the connected households and fire station with updates on system status and battery levels. Once PSE restores power, the system automatically and seamlessly resynchronizes with the main grid.

PSE will use the Samish Island microgrid as a working lab—an environment to deepen their understanding of microgrid capabilities and apply that knowledge to future projects. The solution models how utilities and customers benefit from integrating renewables into the grid to strengthen the resilience and reliability of electric power. The collaboration also demonstrates how small-scale projects can make big impacts on a community.

“Having power backup has been a goal of ours for a long time,” Samish Island Fire Chief Michael Collins said. “Now we have power that’s dependable and extensive enough to keep us going, keep the lights on and be able to get out the door to serve our community in the fashion they expect.”