Fire Station Plans 92.8 kW Solar Array and 125 kW Battery Backup System

The Public Works Committee meeting held on July 17, 2025, in Tumwater, Washington, focused on the proposed installation of a solar photovoltaic (PV) array and battery energy storage system at the main fire station. The project is designed to enhance energy efficiency and provide backup power during emergencies.

The proposed solar PV array would generate 92.8 kilowatts, while the battery energy storage system (BES) would have a capacity of 125 kilowatts. Together, these systems are expected to cover approximately 70% of the fire station's annual energy consumption, yielding an estimated first-year savings of $10,500. The design aims to ensure that the fire station can operate autonomously during power outages, with the system capable of sustaining normal demand for over 24 hours in emergency situations.

During the discussion, it was noted that the current backup generator at the fire station only supports essential loads, highlighting a need for additional backup power capacity. Community feedback indicated a preference for a hybrid system that combines battery power with generator support. The proposed design incorporates a primary reliance on the battery, which will activate the generator only when the battery's charge is low, ensuring that essential services remain operational during emergencies.

The committee also addressed safety concerns related to the installation of the battery energy storage system. To comply with Washington fire code, a few small trees will need to be removed to create a safe clearance zone around the battery system. The design includes a fire suppression system to mitigate risks associated with battery storage.

The estimated cost for the construction of the solar PV array and battery system is projected at $1.6 million, representing a high-end estimate. The project is considered shovel-ready, pending the necessary permits.

In conclusion, the meeting underscored the city's commitment to enhancing energy resilience at the fire station while addressing community concerns and safety regulations. Further steps will involve securing permits and finalizing project details before construction can commence.