Connected Energy, Dundee City Council Partnership (Case Study 3)
Dundee City Council has created the UK’s first Electric Vehicle (EV) charging hub which includes a number of 22kW and 50kW chargers, PV charging canopies and energy storage.
In the longer term, the purpose of the energy storage system will be to manage peak loads from the charging units. In the shorter term however, as well as trialling peak shaving, the storage system is managing the on-site generated PV to ensure as much as possible is used by the chargers.
It also takes advantage of any time-of-day energy cost differences. In this way people charging their EVs benefit from as much renewable generation as possible, and Dundee City Council minimise the cost of supplying electricity to the chargers.
Connected Energy have installed an E-STOR system alongside the EV chargers and PV canopies.
The system tracks the usage of the chargers and the generation of the PV and works to maximise the amount of renewable energy that is used to charge the vehicles. During 2020 the site generated 32 MWh from the PV canopy and used 444 MWh on the chargers. With the solar generation not always being aligned with the charger usage, the site would have only used 88% of the onsite generation. However, the E-STOR battery system captured nearly all of the surplus energy to achieve a renewable energy usage of 97%. A net carbon saving for the year was 521 kg of CO2e.
In addition to the renewable enhancement, the system monitors and reacts to peaks in energy demand from the chargers. This allows for management of the maximum power draw for a site. Whilst the Dundee charging station is able to fully run all the chargers without the battery, a lower target limit for the site was has been demonstrated. From this learning a battery system can be effectively sized to maximise the charging network being installed above a limited connection.
Data from the E-STOR system is being captured and displayed through the connected energy management platform. A near to real time visualisation of the site operation has been given to the site owner to understand all the elements of the charging station. Further, insights on charging habits and battery usage can be drawn from this data.