TenneT has developed a new concept for high‑voltage lines with a magnetic field intensity that is significantly lower than that of existing lines. The innovative design is called Wintrack and consists of pairs of slender pylons from which the high-voltage wires are suspended. Thanks to the new pylon, optimum use can be made of the space available around high‑voltage lines. TenneT intends to apply this innovative pylon at various locations throughout the Netherlands, including in the Randstad region, where work is currently underway on a major expansion of the high‑voltage grid.

In the fulfilment of its duties, TenneT tries to find a balance between a reliable electricity supply in the Netherlands, the associated costs and TenneT’s social responsibility in its capacity as grid administrator. The development of the new Wintrack concept, together with the independent research agency KEMA, offers TenneT more opportunities than before to arrive at the best possible solutions in concrete situations – in technical, economic and social terms.

The high-voltage conductors are suspended closer together than in traditional high-voltage pylons, thus reducing the intensity of the magnetic field generated along the line. The design consists of a pair of slender, tapering pylons that appear as visually distinct elements. Thanks to their design, the pylons can be integrated into the landscape in an attractive manner. The pylons are also easy to maintain thanks to their simple structure and smooth surfaces.

The Wintrack project is also important because the Dutch Ministry of Housing, Spatial Planning and the Environment drew up strict guidelines in 2005 for the extension of high-voltage lines and the construction of new buildings near existing high-voltage lines. The Ministry’s precautionary policy is aimed at minimizing long-term human exposure to magnetic fields generated by high-voltage lines. TenneT follows this policy and will ensure that the limit value of 0.4 microTesla defined by the Ministry is not exceeded. With respect to high-voltage lines of 380 kV, the directive stipulates that no new buildings may be erected on a strip of land of approximately 300 m around these lines. With the new Wintrack pylon, however, this strip can be reduced to less than 100 m.

The Wintrack pylon will be used in the new Randstad 380 line, which runs from Wateringen to Beverwijk. This line will be constructed in stages from 2009 onwards. The Wintrack pylons will be tested extensively in the first half of 2008.