Performance prediction of a vanadium redox battery for use in portable, scalable microgrids

Abstract

Vanadium redox batteries (VRBs) have proven to be a viable energy storage technology for portable microgrids due to their rechargeability and high energy density. Pumping electrolyte across the membrane during charging and discharging cycles of the VRB leads to a parasitic load loss. To ensure the electrical equipment is not exposed to extreme ambient temperatures, VRBs must also have temperature control in the form of heating, ventilation and air conditioning, which also result in parasitic load loss. This paper focuses on empirically characterizing VRB efficiency based on known climatic operating conditions and load requirements. A model is created to determine system performance based on known climatic and load data collected and analyzed over an extended time period. A case study is performed using known data collected over a weeklong time period to characterize system performance, which was compared to actual system performance observed during this same time period. This model effectively predicts peak available ac/dc load as well as VRB efficiencies based on climatic field measurements and VRB state of charge (SOC) and estimates appropriate sizing of the PV array and discretionary loads based on required energy density of the system.

State of the Art in Research on Microgrids: A Review

“…The paper explains that because the energy source of inverter-based microgrids responds slowly, ESS is only necessary for inverter-based microgrids with a mostly critical load designed to have a power quality higher than the utility grid, and is optional for other types of microgrids. The study in [29] focuses on empirically characterizing Vanadium Redox batteries efficiency, as a viable ESS technology for portable microgrids, based on known climatic operating conditions and load requirements. The study in [30] proves that ESSs applied in microgrids can perform the task of active power balancing and voltage regulation at the same time.…”

Modeling of vanadium redox battery by field analysis and neural network approach

“…The pump speed is associated with the VRB SOC and in the deployed system, it is a five stage gear pump [19]. Gear staging is a function of both SOC and VRB output power and is consistent during both charge and discharge periods.…”

Using TMY3 data to stochastically predict the performance of a PV/VRB microgrid

“…Those environmental factors may also impact the operational efficiency of the energy storage devices. For example, Vanadium Redox Batteries (VRBs) and other batteries are impacted by ambient temperature [6].…”

“…Huang et al [8] found that the performance of a PV system is mainly influenced by weather, solar irradiance, and module temperature and were able to develop an evolutionary programming algorithm to predict the performance of a grid-connected PV system based on those influences. Guggenberger et al [6] created a microgrid performance model which characterized the performance of a PV/VRB microgrid based on the operation of a backup diesel generator. This deterministic model used typical meteorological year 3 (TMY3) data for the Global Horizontal Irradiance (GHI) and temperature input values for a microgrid located at Fort Leonard Wood in Pulaski County, Missouri.…”

“…This paper describes the development of a MCS model based on the Guggenberger et al [6] deterministic model for a PV/VRB microgrid. The model includes four random variables: GHI, ambient temperature, VRB state of charge (SOC), and energy load.…”