IET report weighs up grid transmission costs

Delivered in conjunction with engineering consultancy Mott MacDonald, the report found that underground AC cabling was 4.5 times more expensive than overhead lines. As an example, a typical 15 km long 5000 MW overhead line was estimated to have a build cost of nearly £40m, with an equivalent underground cable costing around £330m.

Offshore high voltage direct current (HVDC) point-to-point cable was found to be around 5 times more expensive than overhead lines, while an offshore HVDC network connecting multiple sites to the onshore grid was around 11 times more expensive. According to the report’s authors, the findings can inform policy makers, local authorities, communities and bill payers, helping them weigh up transmission costs versus other factors such as environmental impacts, delivery times and carbon intensity.

“Access to a cleaner, more affordable, more secure supply of energy requires the biggest programme of electricity and transmission network development in at least two generations,” said Keith Bell, Professor of Power Systems at the University of Strathclyde and Chair of the Project Board for the report.