SSEPD seek to understand the benefits of installing electrical energy storage connected via 4 quadrant power conversion systems on the Low Voltage (LV) network. The selected storage technology is lithium ion batteries. The increase in solar PV and Electric Vehicles (EV) does not currently pose a significant issue for network operators. However should this trend continue, there is the potential to have reactive power flow issues and thermal and voltage constraints on significant numbers of low voltage feeder circuits.

Energy storage has the potential to manage the reactive power flows and reduce the peak demand generation through peak lopping. This will reduce the need for traditional reinforcement, thereby stopping the network from becoming a barrier to the deployment of low carbon technologies. SSEPD is proposing to install 3 single phase 25 kWh / 25 kW peak lithium ion batteries at strategic points on the LV network. In order to model the effect of the solar PV and peak demand SSEPD has identified a site with considerable solar generation and electric vehicle charging points.

SSEPD will model and analyse the benefits that the energy storage can provide to the low voltage network using theoretical cable limits, which will not pose any risk to the security of supply.

Objectives

At present the problem is not a significant issue for DNOs, however with recent government incentives SSEPD believes that within the next 5 years, this could pose significant issues for all DNOs in GB. If there is a high uptake in solar PV and EVs the likelihood is this will be in a concentrated area. Early results from the Chalvey Tier 1 LCNF project have revealed reactive power flow issues. Voltage and thermal constraints on LV feeder circuits are expected. The present solution is to replace the existing cable with one of a larger capacity, the downside being it causes significant disruption to customers, requires full excavation together with long lead times and high cost.