SSEN proposes switching networks mechanism for storm-hit customers

Scottish and Southern Electricity Networks (SSEN) Distribution is proposing to implement measures to allow its customers to receive power from a neighbouring network operator during outages caused by storms.

SSEN is seeking £10.5 million to develop five projects which it says will make its network more resilient to severe weather. It has made its funding plea in its submission to Ofgem’s uncertainty mechanism launched in the wake of Storm Arwen.

The company has requested £100,000 from the regulator to develop cross-DNO interconnection which would be deployed in remote sites close to its border with SP Energy Network’s (SPEN) licence area.

This would install points of connection between the two networks, so that if one side loses supply during a storm, customers can be kept on supply from across the network boundary.

“It’s focused on specific sites where there is benefit to both communities, which could be adopted for a relatively low cost,” the distribution network operator (DNO) added.

Explaining its rationale further, SSEN said: “In certain circumstances, especially at the peripheries where the network can be at the end of a long section of overhead line, it can be difficult to provide sufficient network resilience to storms. In these circumstances, these parts of the network may feed only a small number of customers, or may not be in close-enough proximity to other sites to be able to feasibly put in place additional connections with other network assets.

“In some cases our network assets are close to those of other DNOs and the network is in a similar situation, or there is sufficient infrastructure to provide an additional connection. In these cases, it could be possible to provide a route of interconnection between the two DNOs’ assets, thereby giving an additional source of resilience for customers connected to these assets.”

It added that “for a relatively small investment from the DNOs”, the solution could reduce the need to fix faults during storms and would bring operational efficiencies in managing the network.

Other solutions being proposed by SSEN include:

• Restoring Overhead Line Resilience (£2.1m). This addresses the growing risk to overhead lines in the north of Scotland, where the network was affected by trees blown over during Storm Arwen.
• HV Feeder monitoring (£6.7m). This would see new monitoring devices installed on SSEN’s High Voltage and Extra High Voltage networks to help it locate faults more accurately.
• Wood Pole Condition Assessment tools (£1m). This would see SSEN roll-out smart tools to its teams to help them to better assess the condition of the wooden poles on the network.
• Satellite communication systems (£0.7m). This would help communications, which are often challenging in remote areas, especially during storms, when mobile phone masts can be affected. SSEN wants to pilot a system that uses direct connections with satellites to provide a more robust communication network.