Green Chemistry Challenge: 2017 Small Business Award
UniEnergy Technologies LLC
The UniSystemTM: An Advanced Vanadium Redox Flow Battery for Grid-Scale Energy Storage
UniEnergy Technologies, LLC (UET), Mukilteo, Washington, in partnership with Pacific Northwest National Laboratory (PNNL), is being recognized for an advanced vanadium redox flow battery, originally developed at the PNNL and commercialized by UET. The battery, when used by utility, commercial and industrial customers, allows cities and businesses more access to stored energy. It also lasts longer and works in a broad temperature range with one-fifth the footprint of previous flow battery technologies. The electrolyte is water-based and does not degrade, and the batteries are non-flammable and recyclable, thus helping meet the increasing demand of electrical energy storage in the electrical power market, from generation, transmission, and distribution to the end users of electricity.
Summary of Technology:
The evolving demands of the energy market call for alternative energy storage technologies capable of both long and short duration operation and as long-lasting assets to deliver a maximum value to customers. Current battery chemistries based on Li-ion have proved to be competitive for relatively short duration (2 hours or less) applications such as frequency regulation, given their excellent power capability and battery cell energy efficiency. However, they may not always be a competitive solution for customers that need long duration benefits, as Li-ion batteries degrade over time and have limited cycle life. In addition, they cannot use their full capacity-rated charge and thus are typically operated between 20-80% capacity, plus have noted challenges with thermal runaway and flammability.
The vanadium redox flow battery (VFB) has emerged recently as a competitive alternative that is capable of delivering competitive value to utility, commercial, industrial, and microgrid customers that require long duration benefits, such as load leveling, peak shaving, islanding, and renewable energy integration, as an essential part of their overall value propositions for energy storage. However, the traditional VFB’s drawbacks included a large ground footprint to operate and stability limited to a narrow temperature range of 50 to 95 °F.
UniEnergy Technologies’ third generation vanadium redox flow battery, the UniSystemTM, utilizes a breakthrough chemistry: a vanadium electrolyte with double the energy density of prior chemistries, and a much broader operating temperature (-40 to 120 °F) that allows the energy storage system to be deployed in nearly any ambient temperature or environment on earth. These improvements have resulted in a fully containerized and deployable megawatt-scale vanadium redox flow battery technology with one-fifth the ground footprint and greatly reduced chemical usage compared to previous flow battery technologies. The new vanadium electrolytes, with a chloride-based complex chemistry, have a much improved stability over traditional sulfate-based chemistries. UET’s improvements in system integration and controls have made the deployment, operation, and maintenance of this chemical battery simpler, cost effective, and safe. Because the vanadium electrolyte is water-based and does not degrade, the batteries are non-flammable and recyclable.