Flow Batteries : Has Really Large Scale Battery Storage Come of Age ?
The market for electrical energy storage (ES) solutions has been mostly limited to relatively small applications of battery uninterruptible power supply systems (UPS’s) and very large site-specific systems such as pumped hydro storage, two completely different types of ES with separate markets. Flow batteries (FBs) are promising to change that by providing a technology that can potentially span this entire range of applications. Flow batteries have demonstrated providing ES from sub-second local power reliability to hourslong load shaping and price arbitrage functions at the large commercial end-user-scale (500 kW, 520 kWh). Several pilot plants have been built at this scale and early results are positive. In addition, pilot utility-scale systems (12 megawatt, 120 megawatt-hour) are being constructed. The scale and variety of these pilots reflects high confidence in this technology by developers. This paper details technical principles of 2 competing flow battery technologies available in the immediate future, compares their market-readiness, and analyzes economics and market potential for this technology to compete with UPSs as well as play into new commercial load management markets.
A field trial of a Vanadium Energy Storage System
This Paper describes the establishment of a Userbased field trial of a Vanadium Energy Storage System (VESS) incorporating a 250 kW/520 kWh Vanadium Redox Battery (VRB). The trial is significant in that the system is the first commercialscale VRB installation outside Japan.
The vanadium redox battery for emergency back-up applications
Secure and reliable power is essential in areas such as telecommunications and information technology to safeguard the vast computer networks which have been established. Uninterruptible power systems have incorporated battery technology to allow smooth power feeding switch-over in the case of a power failure. In such systems lead-acid batteries have commonly been used until generators come online or for safe computer shutdown. A new battery system, the vanadium redox battery is under development at the University of New South Wales, Australia, which provides many advantages over conventional batteries for emergency back-up applications. This system stores all energy in the form of liquid electrolytes which are recirculated around the battery system. The electrolytes can be recharged an indefinite number of times, or the system can be instantly recharged by mechanically exchanging the discharged solution with recharged solution. A vanadium battery emergency back-up system has been designed and tested for operation between a restricted voltage operating range of 22-28 V. The system achieved energy efficiencies above 80% and coulombic and voltage efficiencies as high as 96.4% and 92.2% respectively depending on the load. The system demonstrated excellent performance characteristics with a capacity utilisation up to 94% of theoretical values.