Summary
Over the past several decades, a number of overhead line (OHL) towers have failed as a result of climatic loading. In the 1970s and 1980s, most failures were linked to heavy snow or ice accretion. In contrast, over the last twenty years, the majority of recorded failures have been associated with localized microburst events—commonly known as downbursts. Although the absolute number of failures remains relatively small, similar trends have been observed in neighbouring countries.
Read more Read lessIn the Netherlands the transmission system operator plans to construct a substantial number of new OHL routes over the next 15 years while also safeguarding the long-term reliability of the existing grid. This makes it essential to understand how downburst behaviour may evolve under a changing climate and to assess the associated risks for OHL structures. At present, however, the influence of climate change on downburst winds is not well understood.
In the Netherlands, OHL design is governed by EN 50341 and NEN-EN 50341-2-15. These standards do not explicitly consider wind loads generated by downbursts, even though such events can produce wind forces that exceed those described in the design basis.
In collaboration with the meteorological institute of the Netherlands, a study has been carried out to analyse future wind-gust characteristics and evaluate their implications for OHL reliability. In the last few years new generation of climate models – so-called convection-permitting climate models (CPMs) were developed, and with these convective wind gust related processes can for the first time be simulated. In this paper three simulations and there outcome are presented.
The simulation results, supported by physical reasoning, indicate that downburst intensity may increase as the Dutch climate warms. Mid-range warming scenarios of +1.5 K to +2 K relative to present-day conditions (consistent with a mid-range emissions pathway) suggest a potential increase in gust strength of 10–15%. From a risk perspective, such an increase translates into a three- to five-fold change in the return period of extreme wind events. These findings remain uncertain, as the number of simulations are limited and no coordinated international research effort has yet been done on the relationship between wind gusts and climate change.
Given these uncertainties and the potential risks for critical infrastructure, greater investment and further research are essential to better understand how downburst events may affect overhead lines. This will help strengthen future design standards and improve emergency preparedness in the event of tower failures
Additional informations
| Publication type | Session Materials |
|---|---|
| Reference | B2_10292_2026 |
| Publication year | |
| Publisher | CIGRE |
| Country | Netherlands, The |
| Study committees | |
| File size | 3 MB |
| Price for non member | 30 € |
| Price for member | 30 € |
Authors
PLATENKAMP Erwin - TenneT TSO; STOOP Laurens - TenneT TSO; LENDERINK Geert - KNMI; BÖRGER Tom - DNV
