A 400-kV transmission line connecting central and southern Scotland is set for a major refurbishment under a £110 million (US$146.6 million) contract awarded to energy infrastructure specialist M Group by ScottishPower Energy Networks (SPEN), ScottishPower’s distribution network business and Iberdrola Group’s subsidiary in the UK.

The project will replace more than 70 kilometers (43.5 miles) of overhead line along the Strathaven to Smeaton route, which runs from South Lanarkshire to East Lothian. The line is one of the main transmission corridors between Glasgow and Edinburgh.

The existing line was constructed in the 1960s. As part of the refurbishment, M Group will replace its key components and install almost 1 million meters (621 miles) of high-capacity conductor.

The upgrade is part of SP Energy Networks’ broader investment in Scotland’s transmission network as the company works to increase the capacity to move electricity, support future demand and reduce constraints on the grid.

“This contract award to M Group is representative of the kind of economic growth being generated by our £12 billion (US$16.3 billion) investment in upgrading the electricity transmission infrastructure in central and southern Scotland,” said Guy Jefferson, transmission managing director at SP Energy Networks.

The M Group contract is being delivered through SP Energy Networks’ £5.4 billion transmission framework. Nineteen companies were selected as preferred partners under the framework to support a planned £12 billion transmission investment program.

The framework includes up to £3 billion for new overhead lines and £2.4 billion for new and upgraded substations, including design, engineering, construction and electrical work.

The strategic partnership will run for an initial five years, with an option to extend to 10 years.

SP Energy Networks owns and operates the transmission network across central and southern Scotland, including more than 4,500 kilometers of overhead lines, 600 kilometers of underground cables and more than 150 substations.

The company also operates undersea high-voltage cables and is constructing two new underwater links off the east coast of Britain.

The investment is part of a broader effort to reinforce Britain's electricity grid. SP Energy Networks said its overall program is expected to create 1,000 new jobs and tens of thousands more across the supply chain.

“We’re delighted to play a central role in delivering this crucial upgrade to one of Scotland’s most important electricity corridors,” said David Maddocks, managing director of overhead lines at M Group. “Our highly skilled teams will fully refurbish the 400-kV Strathaven to Smeaton overhead line, replacing components first installed in the 1960s and deploying advanced high-capacity technology to support future demand.”

UK Minister for Energy Michael Shanks said grid upgrades are essential to providing homes and businesses with secure electricity while supporting investment in domestic supply chains.

“We’re committed to maximising the opportunities for suppliers up and down the country, modernising the transmission network whilst unlocking growth and supporting more highly skilled, high-quality jobs,” Jefferson said.

SP Energy Networks is investing £24 billion in the UK through 2028 as it works to reinforce and expand the electricity grid to support future demand, connect more homes and businesses and reduce network constraints.