The largest smart charging trial in the world

Electric Nation

Western Power Distribution is the distribution network operator responsible for delivering electricity to 7.8 million customers across the Midlands, South West England, and South Wales. Electric Nation is the customer-facing brand of CarConnect, a project funded by Western Power Distribution and Network Innovation Allowance. WPD’s collaboration partners in the project are EA Technology, DriveElectric, Lucy Electric GridKey, and TRL.

Challenge

More and more electric vehicles are seen on the roads of the UK. This is fantastic news, but it also provides a new challenge for the British electricity networks. Can the UK’s electricity infrastructure cope with the new demand of electrified transport? Research shows that the uptake of electric vehicles can potentially stress the power grid.

If 30% of all cars are electric, an investment of 2.5 billion pounds would have to be made to fortify the existing grid if capacity management is not utilized. The Electric Nation project researched if smart charging, provided by GreenFlux, could avoid the need to perform expensive network upgrades.

Solution

GreenFlux’s solution: Capacity management with load balancing. In its search for solutions, EA Technology set up the Electric Nation project on behalf of Western Power Distribution. This project combines smart technologies with new regulations so that cars can be charged quickly without overloading the local network. Already in 700 households, this is the largest Smart Charging EV trial in the world. As a pioneer in the field of smart charging, GreenFlux supports the Electric Nation Project in testing various smart charging strategies.

The data that is collected over a three-year period (2016- 2019) has helped us understand the impact of the charging of electric cars at home on the electricity network. The project was split into three trials to imitate different scenarios. Over the years, trial participants experience periods of no management, and management without and then with apps to enable them to interact with the Smart Charging systems.

The GreenFlux back-office system monitors the overall demand of chargers under their control. Depending on need, the system can diminish total demand by instructing individual chargers to reduce the power available to charging EVs. So that trial participants could interact with the Smart Charging systems, an app was introduced. Under GreenFlux, drivers utilized the application to choose if they needed to prioritise time or cost, and the charger would charge straight away or only charge when off-peak. Requesting High Priority for a charging session excluded the participant from demand management for that session.

Over 60% of trial participants changed their app preference away from the default “Optimise Time”, mostly to the “Minimise Cost” option, thus avoiding the peak price. Demand management was no longer required shortly after introducing the scheme. Meanwhile, a sharp increase in demand was observed at the cheap, overnight, price boundary, as many delayed charging events were switched on. This could lead to negative impacts on various parts of the electricity system such as step changes in voltage caused by sudden changes in demand, or issues with generation capacity. Nevertheless, the new peak in demand could be easily mitigated by implementing randomised or time-band switching.

The trial concluded with participants being financially incentivised to change their charging behaviour, producing clear indications that this could be a successful strategy for addressing distribution network congestion issues that could be created by EV charging at home.

Result

We can deploy our smart charging technology to avoid an overload of the sub-station at high-load intervals. When enabled, smart charging will cause the sub-station to provide information to our cloud platform via an event-based algorithm. Using the latest information gathered from these stations, we can shift power grid resources appropriately, preventing overloads on the sub-station. Our smart charging algorithm considers how full or empty a battery is, allowing us to give priority to cars that need it more.

At Electric Nation, GreenFlux provided a smartphone app that enables customers to request charging priority themselves, overruling our smart charging algorithm when necessary. Moreover, the algorithm controls the chargers in a dynamic way, so all cars are full in the morning with the most efficient energy usage. The use of an app seemed to have an effect on nudging users into economising, thus reducing stress on the local power network.

Time of Use incentives give off an impression of being exceptionally successful at moving demand away from the evening peak – especially when bolstered by Smart Charging through a smartphone application. Smart Charging can support the introduction and management of ToU based charging and can support a means to manage any negative consequences of mass uptake of ToU incentives. The positive reaction to the ToU tariff scheme shows that it is a suitable technique for curbing peak evening demand and that having control by means of a smartphone application is popular.

Working with smart charging enables 10 times more efficient capacity allocation and circumvents the need for potentially billions in additional capital to provide new charging infrastructure.