He estimated the system could mean a 68 percent reduction in power-supply related outages.

Eventually, four strings of batteries will take up about three-quarters of a 500-by-120-foot building. Each string has 3,430 batteries, which will be connected by a power converter and substation to the Fairbanks power grid.

The loss of a generator along the Railbelt can cause a fairly large outage in the Interior so a reserve power system can be valuable for keeping the lights on, said GVEA spokeswoman Corinne Bradish.

The Battery Energy Storage System can produce 27 megawatts for 15 minutes. In comparison, GVEA's peak output in winter is 180 megawatts and the Healy power plant's capacity is 25 megawatts.

Inside the BESS building, large fans circulate air to keep an even temperature. The battery room, power converter room and other portions of the facility will remain mostly unmanned once the batteries are operational. The project is designed to run automatically, charging the batteries when needed, generating power when it's time to prevent an outage.

GVEA hired power and automation technology company ABB, which partnered with French battery-maker Saft, for the project. Fairbanks company City Electric serves as the general contractor.

The batteries began arriving in November and the last are expected in October. Two of the strings could be operational by midsummer, with all four strings expected to be online by the end of the year.