By: Dr. Franyi Sarmiento, Ph.D., Inspenet, April 6, 2022
Scientists have developed a prototype 10 kilowatt (kW) vanadium redox flow battery to demonstrate its viability as a large-scale electrical energy storage system, targeting especially renewable energy such as solar.
This 10 kW prototype (10 kW of power and 20 kWh of energy) allows the accumulation of electrical energy for stationary applications, such as energy storage in homes or small businesses.
This technology constitutes the first milestone on the way to obtain a 50 kilowatt battery, which will allow the use of this technology to be extended to the industrial sector.
This prototype is the result of the work of the Interdisciplinary Thematic Platform PTI TrasnEner+, of the Higher Council for Scientific Research (CSIC) in Spain, and represents a technological commitment for the stationary storage of large-scale electrical energy, with the aim of achieving greater integration of renewable energies, overcome their intermittency problems and accelerate the energy transition. The project is coordinated by Ricardo Santamaría, a researcher at the Institute of Carbon Science and Technology (INCAR), and has the participation of groups from eight CSIC centers: INCAR, LIFTEC (integrated into the ICB), ITQ, IRI, ICB, ICMM, ICMAB and ICTP.
Redox flow batteries are highly flexible devices in which energy is stored in electrolytes, which contain electroactive vanadium species. These electrolytes are found in external tanks and flow thanks to the action of hydraulic pumps inside the battery cells where electrochemical oxidation-reduction reactions take place.
Their main advantage is the versatility they offer: the power and energy of the system can be configured independently by increasing the active surface of the electrodes, the number of cells and the volume of electrolyte. They also have a long life cycle that can exceed 20 years, which makes them excellent candidates for stationary and intensive use applications, where other technologies such as lithium batteries cannot compete, facilitating the penetration of renewable energies. in the market.
“One of the great advantages of redox flow batteries is that they can be sized in power and capacity to serve storage applications both in front of and behind the meter; that is to say, they can be directly connected to generation plants connected to the distribution networks or installed in energy consumption centers or in their proximity”, comments Santamaría.
This 10 kW module represents the first milestone in the project to achieve a 50 kW battery. The prototype is made up of 4 stacks (stacking of cells) similar to those that will incorporate the 50 kW battery. The various components of the battery have been developed by different teams from the CSIC.
The design of all the elements that make up the battery, the technology of the sealing and closure systems, and the manufacturing and assembly processes are the work of the LIFTEC research group led by the researcher Félix Barreras. The carbon felts used as electrodes have been modified by the INCAR research group to improve their electrochemical properties, while the ITQ group, led by Antonio Chica, has been in charge of the membranes and the electrolyte.
The module also incorporates a self-developed battery and energy management system, based on operating protocols compatible with industrial standards, with which the status of the battery can be known at all times.
Likewise, the research group of the Institute of Robotics and Industrial Informatics (IRI), led by Ramón Costa, is collaborating with the LIFTEC group in the design of a telemetry system that allows remote operation of the battery and visualization of all the variables of operation in real time. They are also working on the implementation of techniques for the prediction of the state of charge and health that allow the efficient management of energy flows and the prolongation of the useful life of the device.
The 10 kW prototype could cover the growing needs for residential energy self-consumption both in isolated houses and in small neighborhood communities, or even for small commercial consumers.
However, the ultimate goal of the project is to validate the 50 kW prototype by connecting it to a renewable energy generation plant, such as a solar field. To this end, an intelligent microgrid has been developed at LIFTEC, made up of the 10 kW flow battery, a solar field and several loads and programmable sources that allow different consumptions to be simulated.
As indicated by Félix Barreras, “this installation will allow the study of realistic cases according to the needs of the market, with a modular power architecture that allows the use of the battery in isolated mode or connected to the network, either in alternating or direct current” .
Source NCYT of Amazings / CSIC: https://noticiasdelaciencia.com/art/43999/bateria-de-vanadio-para-almacenar-energia-electrica-a-gran-escala