Introduction: Southern Electric Power Distribution seek to understand the potential benefits, practicalities and costs of installing Electrical Energy Storage (ESS) connected via 4 quadrant Power Conversion Systems (PCS) on the Low Voltage (LV) network. The main objective is to inform and de-risk the larger scale deployment of street batteries as detailed in the New Thames Valley Vision Tier 2 project.

The ESS units with associated PCS have the potential to aid power quality, to manage reactive power flows and to reduce the peak demand / peak generation real power flows, through peak lopping. This has the potential to delay or reduce the need for traditional network reinforcement, thereby preventing the local DNO network from becoming a barrier to the deployment of low carbon technologies. In order to understand the operation of an ESS with relevant low carbon technologies such as solar PV and Electric Vehicles (EVs), Southern Electric Power Distribution has identified a site with established solar generation and electric vehicle charging points. Southern Electric Power Distribution is proposing to install 3 single phase 25 kW / 25 kWh lithium-ion batteries at this strategic location on the LV network.

Objectives: Southern Electric Power Distribution will monitor, model and analyse the operation of the ESS to understand the technical solutions that this technology can provide to the low voltage network. Shadow cable limits will be applied and will not pose any risk to the security of supply. The data and learning obtained will feed directly into the Tier 2 project to support the large rollout of this technology.

In addition the following objectives have been established:

• Prove the batteries and power conversion units can operate as intended on an LV network in GB and have a tangible benefit electrically

• Inform the establishment of the economic threshold for this technology

• Validate the technical specification to inform and de-risk the tendering exercise for the Tier 2 project

• Define, test and prove the communications and the associated data transfer requirements for this small trial and inform that required for a larger array

• Inform the safety case and the operational procedures including installation, maintenance and operational work on a network with storage connected (faults, protection. live working, safety procedures etc)

• Inform decisions regarding the physical location of storage devices given public perception and acceptance.