Ready for tomorrow's challenges
To prepare for tomorrow's technical challenges, a Ramboll employee is currently performing a PhD thesis as an industrial researcher in cooperation with the University of Aalborg investigating how the floating foundations react to strong winds, cyclones and storms.
"The construction costs for the floating foundations are still so large so that the technique is not yet profitable in most cases. But I am sure this will be a widely used solution at some point. We therefore believe that it is important to perfect our knowledge, so that we are also capable of mastering this technique. And one way to do this is to work with the prediction of movement and effects on the structures," says Søren Juel Petersen, Business Development Director in Ramboll.
Ramboll is world leader within the design of offshore foundations for wind turbines and has developed more than 2100 foundation designs for 37 offshore wind turbine farms around the world. In other words, this is more than 65% of all wind turbine foundations installed in the world today.
Ramboll is currently designing the monopile foundations for the Gemini offshore wind farm, which will be one of the world's largest wind farms. Far out in the North Sea, 150 wind turbines will rise from water depths of up to 37 metres and supply more than 1.5 million Dutch citizens with renewable energy in 2016.
Oil – gas – approach
"As we move wind farms further out to sea, we face challenges related to design of larger structures that can withstand the larger waves, the stronger winds and the heavier loads. This means we need to use methods that increasingly resemble those in the oil and gas industries. This includes large structures known from the oil and gas industry that are proven to withstand the massive impact from the waves and forces from the wind," says Søren Juel Petersen.
Rather than building foundations for offshore wind turbines, on so-called monopiles, which consist of steel tubulars 5-6 meters in diameter, the new types of structures are built as lattice structures, the so-called "jacket structures", bottom mounted on the seabed using three or four legs. The jackets resemble the foundations in oil and gas installations, which are built in much deeper water than has previously been the case for wind energy.