Delaware Researchers Discover How to Cut Offshore Wind Construction Costs by $1.6B

Working closely with industry partners, University of Delaware researchers have developed a new method for constructing offshore wind farms and proven that it is cheaper, faster, and could make possible offshore wind deployment at a scale and pace able to keep up with the region’s scheduled retirements of nuclear and coal-fired power plants.

The researchers calculated that their innovative process will cost up to $1.6 billion less per project than conventional approaches and take half the construction time.

“In planning for offshore wind power, the big question is how we generate electricity cost-competitively, and at a scale that is both a relevant replacement for aging power plants and also applicable to climate change,” said the project’s principal investigator, Willett Kempton, professor in the College of Earth, Ocean, and Environment (CEOE).  “We’re the first people who have shown the engineering details, step-by-step, how to achieve that.”

Findings
The key insight that allowed Kempton’s team to make such considerable optimizations in cost and deployment speed was that the entire structure, from seafloor mounting to the top of the turbine, can be assembled in one piece in port, moved as a unit, and in one step placed into the sea floor.  It may seem like a simple idea, but it was by no means obvious that it would work with existing equipment until completing the detailed engineering and cost analysis.

The reference design used 10-megawatt turbines with support structures, together standing twice as tall as the Statue of Liberty and weighing 2500 metric tons, the equivalent of 183 semi tractor-trailers.  Figuring out how to build and move them around in port was the final hurdle surmounted in the five-year study’s new construction method.

“Instead of today’s method, carrying out parts separately and individually assembling each in the ocean, we have an assembly line on shore,” Kempton said.  “We spend more money in port, but we spend far less money at sea.”

In addition to cost savings, there are non-monetary benefits:  shifting more of the assembly to land enables construction to proceed regardless of the weather and reduces time at sea from three days to 10 hours for each turbine installed.  Integral to the method is to anchor the turbines by suctioning large buckets to the seafloor rather than pounding in long cylinders of steel, called piles.  This also means that the foundation doesn’t penetrate as deeply into the seafloor, which reduces costs for everything from the attachment process to the surveying required in advance.  And without pile driving noise, installation has no acoustic impact on marine mammals.

Read more and view YouTube at Delaware Researchers Discover How to Cut Offshore Wind Construction Costs by $1.6B