Press Releases

POWER’s underground transmission expertise reinforces Stockholm grid

August 2017

HAILEY, Idaho (August 14, 2017) ‒ Stockholm and its surrounding region will have a stronger electric grid thanks to a new underground 400 kV line designed with help from POWER Engineers Incorporated (POWER).

The underground line is one of several reinforcements being made as part of the project called Stockholm Ström to meet future electricity needs. Stockholm Ström is a collaboration among Swedish utility companies Ellevio, Vattenfall and Svenska kraftnät. When the project is finished, electricity can be fed from several directions in the Stockholm area.

POWER is providing preliminary and detailed design among other services to ÅF, an engineering and consulting company within the energy, industrial and infrastructure sector, for a 400 kV line to be built between Danderyd and Stockholm. For the main part of the 13.4 km (8.3 miles) route, the cables will be located in a rock tunnel drilled through the central parts of Stockholm.

POWER’s services will assist ÅF in designing the complete 400kV XLPE cable system between Anneberg and Skanstull substations for Svenska kraftnät. The tunnel portion is located 50 meters (164 feet) to 100 meters (328 feet) under the most densely populated parts of Stockholm. The tunnel will start at the new substation Anneberg in Danderyd and continue to the new substation Skanstull in Mårtensdal, south of Hammarbyhamnen.

The Svenska kraftnät project is the second stage of a four-stage new electricity connection called City Link. The utility built the first phase with overhead lines. Investigation of the third and fourth stages is in progress.

Tunnel construction is expected to start in 2019 and cable installation is scheduled to start in 2022. The project is expected to be commissioned in 2024.

POWER brings its extensive experience with underground transmission projects to this effort. These projects include a 40.2 km (25 miles) undersea and underground cable for the first U.S. offshore wind energy project as well as one of the longest cross-linked polyethylene power cable installations within a directional bore to date in the United States.

About Svenska kraftnät: Svenska kraftnät is the authority responsible to ensure a safe, environmentally sound and cost-effective transmission system in Sweden. The Stockholm region is rapidly growing. With more than 2 million citizens, a large number of industries, companies and activities, there is an increasing need for reliable electricity supplies. A new structure for the regional grid in Stockholm, the Stockholm Ström project, is being realized in cooperation with energy companies Vattenfall and Ellevio. The new, planned connection, which will run through a tunnel from Anneberg in the north, under the center of Stockholm, to Skanstull in the south, is one of many important investments in the regional grid to meet future electricity needs.  

About POWER Engineers: POWER Engineers is a global consulting engineering firm specializing in the delivery of integrated solutions for energy, food and beverage, facilities, communications, environmental, and federal markets. POWER Engineers offers complete multidiscipline engineering, architectural and program management services. Founded in 1976, it is an employee-owned company with more than 2,300 employees and more than 40 offices throughout the United States and abroad.