Utility Savings & Refund, LLC

From Open Energy Information

Utility Savings & Refund, LLC is a sales affiliate and strategic partner to Prudent Energy, manufacturer of the Vanadium Redox Flow Battery - Energy Storage System (VRB-ESS™).[1]

The VRB-ESS is an electric energy storage system capable of nearly unlimited deep charge and discharge cycles, long lifetime - 10 to 20 years - with minimal maintenance, large capacity - in the megawatts, and rapid response. Potential applications include renewable integration - solar and wind, peak shaving - load shifting, uninterruptible power supply - UPS, frequency regulation, power quality and emergency power - black start.[2]

Moab Interior.jpg

The Vanadium Redox Battery converts chemical energy into electrical energy. Energy is stored chemically in different ionic forms of vanadium in a dilute sulfuric acid electrolyte. The electrolyte is pumped from separate plastic storage tanks into flow cells across a proton exchange membrane (PEM) where one form of electrolyte is electrochemically oxidized and the other is electrochemically reduced. This creates a current that is collected by electrodes and made available to an external circuit. The reaction is reversible allowing the battery to be charged, discharged and recharged.


The principle of the VRB is shown in more detail above - it consists of two electrolyte tanks, containing active vanadium species in different oxidation states (positive: V(IV)/V(V) redox couple, negative: V(II)/(III) redox couple). These energy-bearing liquids are circulated through the cell stack by pumps. The stack consists of many cells, each of which contains two half-cells that are separated by a membrane. In the half-cells the electrochemical reactions take place on inert carbon felt polymer composite electrodes from which current may be used to charge or discharge the battery.

The VRB-ESS employs vanadium ions in both half-cell electrolytes. Therefore, cross-contamination of ions through the membrane separator has no permanent effect on the battery capacity, as is the case in redox flow batteries employing different metal species in the positive and negative half-cells. The vanadium half-cell solutions can even be remixed bringing the system back to its original state.[3]

The VRB-ESS is a device that is capable of storing energy in multi megawatt ranges and for durations of hours or days - from any available input source such as the Grid, Renewable Resources or local generator. The stored energy can then be provided back into the Grid or supplied to a load as required and directed. It is uniquely capable of being charged as quickly as it was discharged and is able to respond to all forms of power quality variations so it can be operated in an Uninterruptible Power Supply (UPS) mode as well. For loads which require reactive energy, the VRB-ESS is fully rated to provide VARS at nameplate on a continuous basis either when charging or discharging.



  1.  "Prudent Energy Strategic Alliances"
  2.  "PowerPedia:Vanadium redox batteries"
  3.  "More information on vanadium redox system"