Fire Hall Solar-Electric System

A datalogging system donated by Fat Spaniel Technologies gives us real-time and cumulative data on the Guemes Island Fire Station backup power system performance.

"Generating and Generated " is the total solar electricity generated.
"Used and Using " is the electricity purchased for back-up loads and battery charging.
"Back-Up Load " is the total electricity used by the back-up circuits (this may include some or all of the "Generating and Generated" and some or all of the "Used and Using")

The Guemes community, with the support of the island energy club, equipment suppliers, and others, raised the funds and installed a solar-electric backup system at the Guemes Island Fire Department in the summer and fall of 2007. It provides the fire hall with clean, local electricity, while providing several days of backup for critical loads during utility outages.

The Fat Spaniel monitoring system collects data on solar energy generated, back-up circuit energy used, and grid electricity used for back-up loads and battery charging. It does NOT measure all fire hall usage--only back-up circuits.

How It Works

Sunshine hits the array of forty-five 180-watt solar-electric (photovoltaic; PV) modules on the roof, making DC electricity. These modules have a 25-year warranty on energy production, and will likely be producing solar electricity for the next forty-plus years. Electronic components in the fire hall regulate the charging of the batteries, so they are full in the event of an outage.

Inverters convert the DC electricity to grid-synchronous AC. When the system is producing more electricity than the fire hall is using, the surplus is sold back to the utility, "spinning the meter backwards" and creating a credit. When the buildings are using more than the system is producing, electricity flows from the utility, using up the credit. The system was designed to produce all of the fire hall's electricity annually.


The solar-electric module on the wall of the fire hall is the same as the forty-five on the roof, mounted there so you can see and touch it. It's part of a small system that powers the lighting for this sign. It is not connected to the utility grid.

Thanks to: Guemes Island community members, Guemes Island Fire Department , Solar Energy International , OutBack Power Systems , AEE Solar , Uni-Rac , Dyno Battery , Fat Spaniel Technologies , Quality Electric Plus, Dakota Creek , All-Phase Electric , Home Power magazine , and others.

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