Today, turbines with over 5.5MW are planned, with rotors at more than 160m diameter - and growing. Constant innovation is needed to complete the many challenges brought about by such rapid change.
For example, lifting technologies available in the marketplace are limited to around 160m hub height. Truck-mounted cranes with strengthened lattice booms have been widely used but going beyond this height becomes a challenge.
Building over 160m requires heavy crawler cranes that are not designed for wind farm installations, nor to accommodate the industry’s fast paced schedules. They also have relatively low market availability and global spread.
These heavier lifting machines bring other issues. Extra civil works are required to accommodate crawler cranes’ larger working radius with wider areas to move counterweights, long boom down corridors and lengthy, costly processes to relocate the crane between wind turbine pads. Not to mention the cost of building wider hardstands around each WTG.
This is why tower cranes like the Kroll K1650L have been used for high hub height installations. They are especially useful on projects where the orography of the site is an issue; when aspects like removing trees or preparing pads on mountainous sites becomes too costly.
Their smaller footprints allow for less impactful civil works and faster movement between turbines during installation. They have also benefitted projects where wind conditions are severe, as they have higher wind speed limits compared to truck-mounted cranes or standard crawler cranes. However, even these are not an ideal solution, as they too have a hub height limitation of around 160m, making them ill-prepared for such a changeable market.
WTG installation costs must therefore be considered holistically - by considering the entire installation process at the start of the project, design changes can be made that facilitate later savings. This requires coordination with the crane service provider as well as the civil works designer to ensure the whole installation process is optimized during the development phase.
Mammoet is committed to producing innovative ideas to help our customers succeed and realise their goals. We have therefore designed a solution to install the turbines of the future, reaching over 200m hub height and lifting loads up to 300t.