ESP30 battery. Image: Imergy
Energy storage developer Imergy Power Systems has announced the installation of a 30kW, 120kWh ESP30 vanadium flow battery to be tested with PV systems at the SunEdison and Global Academy of Technology (GAT) solar research and testing centre in Bangalore, India.
The flow battery has duration of four hours at nominal power and will be used to reduce the college’s reliance on diesel generators during power outages at night.
Vanadium Redox is the most common flow battery technology and it presents potential cost savings compared to lithium ion batteries, which have energy costs that scale up “linearly”, Dr Rahul Walawalkar of the India Energy Storage Alliance (IESA) told PV Tech Storage.
Walawalkar said that flow batteries have the advantage of being able to decouple power and energy.
He added: “The power rating of a flow battery is dependent on the surface area of the membrane while the energy rating is dependent on the quantity of electrolyte and size of the tanks. So it is cost effective to add more energy (longer duration).”
Furthermore vanadium redox flow batteries have an expected life of more than 5,000 cycles, which translates into a 15-year lifetime if used for 200-300 days annually.
Imergy claimed that its ESP30 battery can withstand temperatures ranging from -20 degrees Celsius to 55 degrees, with no reduction in performance.
The new battery will be installed outside the engineering school GAT College solar centre, which solar developer SunEdison helped create in collaboration with the college. Since commencing operation in March 2014, the centre has been used to study solar water pumps, storage solutions, hybrid systems, solar power plant monitoring and mounting structures.
The college faculty and students will investigate how vanadium flow batteries work in connection with PV systems. They will also look at how rural microgrids can use such energy storage to maximise power production, especially in the case of power outages.
For example, earlier this year SunEdison announced it plans to power rural electrification and micro-grid projects in India, including purchasing more than 100MWh of vanadium flow batteries from Imergy.
Rahul Walawalkar said the two main research areas for improving flow batteries are increasing efficiency and reducing the membrane and electrolyte costs.
Imergy Power Systems chief executive Bill Watkins said: “Vanadium flow batteries like the ESP30 are particularly well suited for use in India, where most energy storage users need long-duration energy storage, and where most installations are located outside and experience extreme temperature conditions.”
India suffers from unreliable access to the grid and regular electricity blackouts. In tandem with the country's ambitious renewable energy goals, which include a target of 100GW of installed PV capacity by 2022, some commentators including Walawalkar from IESA believe storage, grid and micro-grid projects will form part of an energy infrastructure transformation for India.
Imergy recently provided flow batteries to the Indian warehouse locations of Singapore-based property development company Assetz Property Group (APG). According to APG, Imergy’s vanadium redox flow battery systems were selected for their low cost and high performance.