Using vanadium redox flow batteries for the electricity storage towards the electric vehicles fast charging process

Abstract

The multitude and magnitude of the problems deriving from the use of fossil fuels for road transport is widely known. Therefore, electric mobility associated with renewable energy sources seems to be a good solution for minimizing these problems. However, the time required to charge the batteries of Electric Vehicles (EVs) and the availability of charging stations are seen as critical factors for their market viability. The use of fast charging stations is a possibility to mitigate the long time required to charge the batteries, but the high cost for power availability makes their operation very expensive. Moreover, it might be difficult to find suitable and affordable locations for installing these stations, so gas stations seem to be good candidates for this purpose. This paper assesses the use of fast charging stations for EVs in conjunction with Vanadium Redox Flow Batteries (VRFBs). Taking into account the low energy density of VRFBs, they are especially suited for situations where volume and weight are not limiting factors. Moreover, their liquid nature allows their installation inside deactivated underground fuel tanks located at gas stations. A preliminary assessment of a VRFB system for EVs fast charging stations taking advantage of existing gas stations infrastructures is presented. An energy and cost analysis of this concept is outlined, including a sensitivity analysis which shows that the project is technologically and economically viable for the conditions tested, although with long payback times.