Consultations on the costs incurred by National Grid in balancing the system highlight some of the issues that arise as more embedded generation is installed.

In its T1 price control, the system operator (SO) included £39.5 million to protect against rising fault currents at nine sites. But four years later, “fewer than expected generation connections to the transmission network means that the previously forecast increases in fault currents are now not expected to materialise” at eight of the sites, according to Ofgem’s costs consultation, reducing the cost to £1.4 million.