The future of vehicle charging?
Dr Alex Mardapittas, managing director of Powerstar, discusses how stored energy can assist local electricity infrastructure and reduce limitations hampering the wider adoption on electric vehicles throughout the UK.
The market for electric vehicles (EV) in the UK is growing exponentially; in 2012, there were approximately 3,000 vehicles on the country's roads, with the latest released data showing that as of late 2016, there are now over 90,000 electric vehicles registered in the UK.
The rapid acceleration is due to continue with Chancellor Philip Hammond announcing the Government's support for the use of electric vehicles in the Autumn Statement, setting aside £390m to aid the electric vehicle infrastructure network across towns and cities. It is evident that with Government backing and private investment there will be a larger electric vehicle network within the UK in the years to come.
Not only will the number of low emissions vehicles increase, so too will the availability of EV chargers, with an increase in the proportion of high power (rapid) units being installed across the UK. Currently, out of a total number of 11,750 EV chargers across the country, only 959 are rapid chargers (50kW output) capable of powering a standard electric vehicle to 80 per cent capacity in 30 minutes.
The capacity for change
The limitation to wider exploitation of rapid charge EV stations is due to electric vehicles requiring a significant amount of locally sourced electricity from the National Grid in order to reach a full charge and currently, with a growing energy gap between supply and demand, many regions are already relying on expensive imported electricity and back-up measures to avoid power shortages. As figure one shows, in the South East alone, there is limited capacity available to manage any additional demand.
Adding demand on an already struggling local energy network in the form of electric vehicles will have a further detrimental impact for everyone within local communities, possibly leading to homes and businesses suffering from frequent power losses and even failings of critical electrical equipment.
Most local energy networks would struggle with additional 50kW rapid chargers, which are currently limited to non-residential areas where the supply can tolerate a sudden increase in electricity demand. Even many medium-sized companies would struggle to charge more than two cars at the same time using a rapid charging point.
The adoption of electric vehicles is also being hindered by several factors including pricing, range anxiety and charging times.
Many electric vehicles are still limited by range, with the vast majority offering a third of the range of a standard fuel vehicle. To improve range, battery capacity is being increased, which may require a rapid charger capable of delivering 300kW output. However, this will cause an even greater increase in demand from the local electricity network.
What's more, it takes a maximum of two to three minutes to fill a fuel-powered vehicle compared to a period of 20 minutes to eight hours for an electric vehicle. Charging time is adversely affected by the output capacity of the storage medium and how much electricity there is available on the local grid. With demand already high on many local electricity infrastructures, charging times are likely to remain high.
Using locally stored energy
These limitations can be addressed in several ways, such as increasing generation (nuclear, wind, solar) to expand the network's capacity with more powerlines and more/larger substations. Alternatively, flexible generation could be added to deal with spikes seen from chargers - this will mean there won't be over capacity on the grid that would need balancing.
Of all the options available, introducing locally stored energy to greatly reduce demand spikes seen when using stored energy to deal with sudden ramp up of power is the most viable and cost-effective solution.
Local storage solutions will also have the added benefit of being able to integrate with any onsite renewable or local generation, such as solar, to charge vehicles. Energy storage based electric vehicle chargers also increase the green credentials of cities and users throughout, an important factor as the Government aims to reduce carbon emissions by at least 80 per cent from 1990 levels by 2050.
Interestingly, it is currently estimated that only 25 per cent of the UK electricity network is powered by renewables, which means if an electric vehicle is charged on the grid, it is still charged by fossil fuels.
By storing energy from integrated renewable generators, including solar PV and local wind turbines, and making it reliable, energy storage EV chargers will ensure electric vehicles powered by the solution will be 100 per cent emissions-free.
The planned growth by the UK Government will combat the question marks of charging stations. However, even though the EV network is due to expand rapidly, there is a plethora of local energy infrastructure complications currently restricting the use of electric vehicles, which also has the potential to restrict the widespread adoption.
By introducing a local energy storage technology connected to an EV charging point, it can reduce the cost of investing in costly vehicle infrastructures and remove any upgrading distribution while producing 100 per cent emissions-free transport, which all benefits the local community.
Powerstar designs and manufactures Virtue energy storage solutions, including the recently launched Virtue EV; a combined rapid/fast electric vehicle charging station with energy storage.