Vanadium-Hydrogen flow battery for energy storage applications - a feasibility study

In order to achieve the goals set up by DECC to drastically reduce carbon dioxide emissions by 2050 it is imperative to
generate a large amount of electricity via renewable sources. Being of an intermittent nature, the renewable sources for
electricity generation require installation of energy storage devices. Redox flow cells are considered to be a strong
candidate to store energy in the range of few kW/kWh up to tens of MW/MWh. An innovative technology, patented and
developed by Imperial College London, has demonstrated excellent performance using a redox flow battery based on the
reaction of hydrogen (gas) and vanadium (liquid), and the feasibility of combining this innovative chemistry into cells and
stacks developed by Arcola Energy will be explored in this project, along with the potential value of the technology for grid
scale storage application (by Alstom UK).

The business proposition is to develop a commercially viable system for energy storage at scale, based on a concept
developed at Imperial College (IC) and leveraging fuel cell technology developed by Arcola Energy. For Arcola Energy (AE)
this represents an additional market opportunity for the core fuel cell technology which de-risks commercial scale up and
leverages investment into manufacturing processes by providing another route to increased volumes and therefore cost
reductions for fuel cell systems. For Alstom the opportunity is to identify a commercially energy storage system and to offer
solutions to the global market at significant scale. All-vanadium redox flow batteries are the most developed and mature
technology today and are commercially available. However, due to relatively high price and low power of vanadium
electrolyte all-vanadium batteries are still costly. Using fuel cell technology one half of the system can be replaced by much
cheaper hydrogen Imperial College has demonstrated a feasible and highly reversible 25 cm2 single cell capable of
delivering 5 W power and Arcola Energy has been successfully developing 4 kW fuel cell (FC) stack for automotive
applications. The project will focus on transforming a 25 cm2 single cell into 250 W stack with 500 Wh storage capabilities
that could potentially be expanded to 1 and 5 kW stacks with system with 2 to 10 kWh storage by adding more bipolar cells
and increasing the size of the electrolyte tanks.
The project therefore has impact through the creation of new IP around cell and stack design, the evaluation of the
potential technological and system benefits of the innovation by Alstom UK, and the exploitation of core IP residing within
two UK entities, Imperial College and Arcola Energy. These impacts will be enabled through this feasibility study. Wider
impacts will be ensured through high quality publications (where appropriate), dissemination through the Energy Storage
Research Network (led by Brandon and Yufit), and links to the new Research Council funded Energy Storage SUPERGEN Hub (of which Brandon is Co-Director)