As the need to lower carbon emissions in the UK heightens, the transition from solely internal combustion engine (ICE) vehicles to hybrid or fully electric vehicles (EVs) accelerates. Despite many people prioritising the reduction of their carbon footprint both in their personal and professional lives, concerns over the practicality of EVs including range anxiety and charging time has suppressed the uptake of EVs compared to its expected boom.
It is clear that EV charging infrastructure is improving, according to data published in November 2019, there are currently 7033 rapid chargers in the UK network , a 43% growth year-on-year . When compared with the availability of ICE fuel, however, around 8,394 fuelling stations exist in the UK , and when the difference in time to charge the vehicles is taken into account it shows how far behind the infrastructure is. Consider a fossil fuel car forecourt transaction that can be completed in under 10 minutes, supporting a steady flow of traffic. In comparison, charging an EV can take from 30 minutes to 12 hours to get to 100% state of charge, depending on the available capacity, meaning that far more charging stations would be required at a rate of three or four to every one petrol pump.
Despite there being a need for rapid chargers, they are not a comprehensive solution as they bring about their own limitations. Rapid chargers can charge a standard EV vehicle from 20% to 80% state of charge in approximately 30 minutes at a 50kW output power. However, they are restricted to areas where the supply can sustain a sudden 50kW load. This means that in highly constrained areas such as city centres where many companies and therefore fleets will operate, a costly grid reinforcement is required in order to install rapid chargers and guarantee enough power is available to undertake the process in the allotted time.
For example, if a commercial company has an electric fleet of 20 vehicles, and these vehicles are kept to a tight 24-hour schedule, it is essential that these vehicles are charged quickly. However, if 10 cars are charging simultaneously at a 50kW rapid charge this generates a large demand of around 500kW which many businesses cannot sustain. To complicate matters further, the cost to upgrade a sites capacity to support this demand has been identified to cost anywhere from tens of thousands up to millions of pounds, eroding the economic benefit of upgrading to an EV fleet.
Buffering the cost
One solution is to support rapid EV charging with battery-based energy storage. This not only enables a business to charge its fleet from the stored energy when required, negating sudden increases in demand, but it will always supply the highest possible charging rate by utilising stored energy to handle the unexpected ramp up in power. This, therefore, eliminates the need to reinforce the grid in order to deliver a rapid charge, saving on the financial costs and operational disruption that would otherwise occur.
As more people and businesses switch from ICE vehicles to EVs there is a necessity for suitable infrastructure to be in place to accommodate this. As habits will change, and simply filling up at a petrol station will no longer be the norm, many will look to charge their vehicles at places where they stay for long durations, such as offices. Battery buffered EV charging is a cost-effective way of meeting this need as it does not require the disruptive and expensive grid reinforcement that installing multiple rapid chargers does, and also has wider benefits to a business through its energy storage component.