Having an emergency response plan in place is essential for when an offshore wind site starts operation, but is also important during the construction phase. Constructing a wind turbine on site in the water can produce a unique set of conditions to contend with, but now a new study has suggested that constructing turbines on land and transporting them to a site may be a more economical option.
Researchers at the University of Delaware, who have been supported by the US Department of Energy, have declared that extensive time and money can be saved by completing most of the construction on dry land, saving as much as 37 per cent in costs.
Willett Kempton, research director for the Center for Carbon-Free Power Integration at the University of Delaware, said that their approach works for not viewing any one stage of the construction process in isolation, according to Green Tech Media: “All those things together should be evaluated as a whole, and then let’s choose the cheapest and fastest-to-build method on that basis. We spend more money in port, but we spend far less money at sea,” he noted.
Time spent constructing at sea, which is particularly expensive per hour, would be reduced from three days to around ten hours under the new process.x
This study was based on ten megawatt turbines, not commonplace in the UK yet, where most turbines have a 2.5-3 megawatt output, however, these kinds of turbines will be commercially available before too long, according to media reports. It’s possible that six/seven megawatt turbines may be operating very shortly as well.
The construction method sees the turbine built on caissons, rather than steel pile foundations, and is largely constructed on land, before the structure, which now weighs 2,500 tonnes, is loaded onto a pier and winched into place.
However, the study is a limited exploration of the construction method at present, with its application only relevant to specific areas with geographical features. The East Coast of America, North Sea sites and some others in water between 60 to 80 metres deep. Construction ports must have open access with no overhead obstruction such as bridges.
With the cost of producing energy by wind tumbling in the UK already, another price cut in the production process could be set to really cement the method as the renewable energy source of choice for future generations.
Mr Kempton has said that feedback to his project have been overwhelmingly positive, quoting industry leaders who say that this will be the future of wind turbine construction. However, though it may be a construction method soon available, he admits it will take some time to catch on: “[Developers] can’t start a large project with something that hasn’t actually been done before. These are $2 billion projects. For anything that size, you’re going to have a cautious approach,” he says.
He also says that even bigger savings, beyond the 37 per cent, could upscale along with the size of turbine technology, with a 20 megawatt turbine yielding even better results. He also sees cost-cutting value in efforts such as additional commissioning in port, co-locating component fabrication and assembly, alongside further industrialising the construction process.