Northern Power Systems Corp. announced its FlexPhase power conversion system has been selected by UniEnergy Technologies (UET) and Avista Corp. to provide advanced power conversion for the largest capacity flow battery deployed in North America.

The battery, located in Pullman, WA near Washington State University and Schweitzer Engineering Laboratories (SEL), went online in April 2015. The project was funded in part by a grant from the Washington State Clean Energy Fund, now in its second round, and Avista matching funds. The batteries are manufactured by Washington-based UET, and integrated with the NPS power converters.

The core of the UET system is an advanced vanadium flow battery, engineered utilizing Pacific Northwest National Laboratories (PNNL) technology developed starting in 2006 with funding from the DOE's Office of Electricity. The system has been used to date by Avista for load shifting, frequency regulation, and voltage regulation on the distribution circuit in Pullman. With the addition of the NPS converters, the UET product will also support Avista's end customer SEL, offering uninterruptible power supply, black start and four-cycle ride-through to SEL's manufacturing facility.