Characterisation of a 200 kW/400 kWh Vanadium Redox Flow Battery

Abstract

The incessant growth in energy demand has resulted in the deployment of renewable energy generators to reduce the impact of fossil fuel dependence. However, these generators often suffer from intermittency and require energy storage when there is over-generation and the subsequent release of this stored energy at high demand. One such energy storage technology that could provide a solution to improving energy management, as well as offering spinning reserve and grid stability, is the redox flow battery (RFB). One such system is the 200 kW/400 kWh vanadium RFB installed in the energy station at Martigny, Switzerland. This RFB utilises the excess energy from renewable generation to support the energy security of the local community, charge electric vehicle batteries, or to provide the power required to an alkaline electrolyser to produce hydrogen as a fuel for use in fuel cell vehicles. In this article, this vanadium RFB is fully characterised in terms of the system and electrochemical energy efficiency, with the focus being placed on areas of internal energy consumption from the regulatory systems and energy losses from self-discharge/side reactions.

A One-Dimensional Stack Model for Redox Flow Battery Analysis and Operation

“…The voltage efficiency also decreases from 96% to 81% with this increase in current density. A thorough comparison with the literature reveals that these efficiencies are definitively overestimated at low current densities, but within the range of reported values at high current densities, as results are widely varied in this regime [103][104][105][106][107]. For comparison, Zhou et al report a voltaic efficiency of 90% and 67% at 80 mA cm −2 and 320 mA cm −2 , respectively, but the authors use Nafion 115, which should have a resistance of 2.5× the value used here, representing Nafion 212 [103].…”

“…Wang et al report voltaic efficiencies ranging from 92% to 67% at 40 mA cm −2 and 200 mA cm −2 , respectively [104]. Recent demonstration and analysis of controlled-power cycling of a system with multiple vanadium flow battery stacks at 50 kW to 200 kW showed voltage efficiencies of 91% to 80% [105]. In this case, the membrane was not reported, and the estimation of the average current density is unclear.…”

Grid frequency enhancement using coordinated action of wind unit with redox flow battery in a deregulated electricity market

“…The source code of MFO algorithm has been modified and coded in a MATLAB (in.mfile) software to minimize the objective function, as derived in (31), in the present study. A laptop having Core i3 Intel processor of 2.54 GHz and 32-bit Windows 10 operating system with 16-GB RAM has been used to execute the simulations and MFO algorithm codes under MATLAB-R2013a environment.…”

“…This type of battery has many benefits over other energy storage batteries such as large capacity, high energy density, easy to transport, ease of recycling, fast charging by replacing exhaust electrolyte, and controllable cell temperature, which make it more appropriate for various applications of modern power system . Other large‐scale energy management technologies (ie, pumped hydro and compressed air storage) are restrained by the suitability of the terrain, whereas RFBs batteries can be easily installed and distributed in suburban areas . In addition, RFBs installation does not require much open space compared with other storage technologies.…”

“…[28][29][30] Other large-scale energy management technologies (ie, pumped hydro and compressed air storage) are restrained by the suitability of the terrain, whereas RFBs batteries can be easily installed and distributed in suburban areas. 31 In addition, RFBs installation does not require much open space compared with other storage technologies. The electrolyte solution of the RFB is containing in the two tanks.…”