Guyed Wind Turbine Towers: Developments and outlook

Abstract

ABSTRACTIn the quest of reducing carbon emissions, sources of renewable energy, such as wind, are in high demand. Developers of onshore wind farms are increasingly faced with site conditions which are not ideal in terms of harvesting wind energy, such as forest, mountain areas or wind availability.This has several root causes such as: site scarcity, political instruments to ensure energy mix and lack of transmission. Some of the potential challenges for such sites are 1) larger hub height is required to maintain energy yield and reduce the turbulence intensity, 2) installation is costly, 3) road transport is costly from increased diameters of conventional towers, and 4) increased foundation cost for tall towers.Guyed masts have been applied within the field of telecommunications for many years. Previous comparisons of the advantages of guyed masts over self‐supporting towers highlights that positive properties of the guyed mast include: lower cost with height, less erection time and cost‐effective foundations.In order to reduce the cost of tall wind turbine towers a guyed wind turbine (GWT) tower concept, where the conventional steel tubular tower is supported by guy ropes (cable stays) just below the tip of the blade, has been proposed by Ramboll dating back to 2003. It is only in recent years that the hub heights relevant for application of this concept is coming into market. In 2013 Ramboll participated in a research project disclosing the use of guyed towers for constructing tall wind turbine towers, which demonstrated a significant positive cost impact and documented the technical feasibility of the concept.For the concept cost reductions are obtained through the entire supply‐chain of the wind turbine tower: steel consumption, foundations, transport and installation.The paper will give a general introduction to the guyed wind turbine tower concept and update with developments.