Aluminium: a lightweight material, with relatively high strength
Aluminium is a lightweight material, with relatively high strength. Aluminium towers are nothing new, but Statnett has never built 420 kV aluminium towers before. In a project supported by the Research Council of Norway, Statnett in partnership with the industry has developed a prototype aluminium tower, which has been tested with good results. The next step is the pilot project, and the first tower will be constructed at Kobbvatnet during summer 2019.
Composite materials becoming more common
Composite materials are becoming increasingly commonly used where a high strength-to-weight ratio is desirable. At lower voltage levels, such as 132 kV and below, composite is becoming increasingly used in load-bearing elements. Statnett is working to develop a new composite tower for 420 kV voltage, with the goal of building and testing a prototype in 2020.
New materials providing cost savings
By using these new materials, Statnett hopes to reduce the number of helicopter trips required to build a tower. This in turn will lead to increased safety, shorter build times and lower overall costs. In addition, these materials do not suffer from corrosion problems, and therefore offer opportunities to reduce maintenance costs.