UK Emphasis on Performance-Based Regulation Drives Lateral Recloser Adoption

Customer Challenge

Western Power Distribution (WPD) is one of the United Kingdom’s largest distribution network operators, with a customer base of 8 million people located in Wales, Midlands, and South-West England. Because of the rural nature of its customer base, WPD’s electrical grid was experiencing a significant number of temporary faults along its lengthy feeder and spur lines. Outages along those lateral lines were becoming a regular nuisance because the region often experiences faults caused by vegetation, wind, and birds, all leading to power interruptions for the operator’s customers.

When temporary faults occurred, they often created permanent outages that forced WPD to dispatch a repair crew. Each site visit cost hundreds of pounds and took the crews multiple hours to make repairs. These outages were leading to increased operation and maintenance (O&M) costs and were negatively impacting reliability metrics. But more importantly, they were affecting customer satisfaction.

To solve future challenges facing British electricity distribution utilities, including addressing reliability issues, British regulator Ofgem created a new, performance-based incentive framework. Called RIIO (Revenue = Innovation + Incentives + Outputs), the programme measures performance in six separate categories, or outputs. However, the outputs are not weighted evenly, with overall grid reliability being given the highest financial weight.

Using the framework in its rate-setting process, Ofgem motivates utilities to create long-term solutions by rewarding them with increased revenue or, inversely, by penalising them if the investment fails to meet performance-based targets.

To maximise the benefits of the incentive framework, one of the key areas WPD chose to concentrate on was improving reliability issues by reducing customer interruptions and customer minutes lost.

After the targets were set, WPD developed a business plan aimed at meeting its performance-based goals, including boosting customer satisfaction and improving overall grid reliability. Accomplishing these critical goals meant the utility needed help to address permanent outages caused by temporary faults along its fuse-protected lateral lines.

S&C Solution

Through a long-term relationship built over many years, WPD turned to its trusted partner S&C for its innovative solutions. To help solve unnecessary outages, S&C suggested using its lateral protection solution, the TripSaver II Cutout-Mounted Recloser, to meet the utility’s ambitious goals.

Because up to 80% of overhead distribution faults are temporary, the single-phase TripSaver II recloser would help prevent such faults from becoming permanent outages. The recloser accomplishes this by testing the line when fault current is detected and closing back in if the source of the problem was temporary. This would drastically reduce customer interruptions and customer minutes lost on the spurs, trim O&M costs by preventing costly site visits, and most importantly, keep customers’ power on. For households experiencing multiple outages throughout the year, this would be a transformational outcome.

Results