“We can certainly improve on that and Ramboll aims at showing that to the market within the recently started FEEDID project that has been funded by the Carbon Trust fund.”
In May 2015 Ramboll was awarded a £700,000 ($1.1 billion) contract by the Carbon Trust to undertake R&D for enhanced or integrated design systems for foundations. The aim of the contract is to compare two different foundation design approaches at the FEED level, comparing the current approach to a new ‘enhanced’ approach.
In his presentation, Fischer highlights a number of areas where costs could potentially come down, not just from a CAPEX perspective, but also from a longer-term operational outlook.
“The equation is simple but still a challenge in the market - invest upfront in early stage development, particularly in the turbine, foundation and wind farm layout and you will save in the long run”, said Fischer.
“A missing link in the market is that once we have designed and installed a project, the measurement data from that project is not taken into consideration in future designs”. This means you have to make the same (often) conservative assumptions when you design the next foundation project. Having data from existing plants, however, would allow stakeholders to optimise the design in a more cost effective and streamlined approach.”
More collaboration between different stakeholders in the supply chain is also crucial in bringing down costs, he said.
“There is still a large potential to use the turbine itself to optimize the monopile. The turbine should become an active element to influence the structural behaviour of the foundation. This will lead to an overall cost reduction, but it requires a holistic approach”.
Fischer suggests the introduction of an incentive program to encourage turbine vendors to support more optimized foundation designs.
“If you can provide benefits to turbine vendors this could change. Say, as the foundation supplier, you indicate that if they re-design the turbine to suit the foundation and this leads to a cost benefit of 10%, they should then be entitled to 3% of that, or something along those lines”.
Finally, Fischer also cautions against implementing best practices used onshore, to offshore projects. “We still need to rethink some of the interfaces – a lot of the processes have simply been transferred from onshore wind, they need to be specifically adapted for offshore wind”.
As an example, turbine vendors still provide the wind turbine towers in offshore projects. But this prohibits an integrated optimization of tower and foundation, since tower and foundation will be optimized independent from each other, Fisher said.
“This [structure] should be optimised in one piece. This separation is a typical onshore characteristic – but is not a good practice for offshore. The tower should be part of the foundation package”.
“Sometimes you can put 20 tonnes of extra steel in the tower rather than the monopile. The benefit of this is that the steel for the tower is cheaper than that for the monopile, but you will never get to this benefit as the tower and monopile are optimised by two different parties who have different targets”.