Dominion thinks $400 million is too much to pay for two experimental offshore wind turbines. The utility is exploring ways to drive the cost down.
by James A. Bacon
When Dominion issued a request for bids this spring to erect experimental wind turbines off Virginia Beach, senior executives knew the project would be expensive. Offshore wind farms are built most economically on a scale of dozens or hundreds of turbines. But this project would have only two, and both would incorporate untested technologies. Moreover, there was no supporting maritime infrastructure on the East Coast of the United States. Key components and construction vessels would have to be imported from Europe.
Internal estimates put the cost around $230 million. The cost per kilowatt of power generated would be so expensive that Dominion executives expected the project to be a tough sell to the State Corporation Commission. But they figured they could make the case that the company would learn enough from the turbines that it could bring down costs for large-scale wind development — some 300 turbines — down the road.
So it was an unpleasant surprise when only two companies bid to build the project, and only one of them in full compliance with the contract specifications. And it was even more discouraging when the sole compliant bid came in at more than $375 million.
“We thought we’d have a challenging [approval] process at $230 million,” said Thomas Wohlfarth, vice president for regulatory affairs at a stakeholders meeting Friday to discuss the future of offshore wind in Virginia. “When the cost went to $375 million, we went, “Whoah!’ We like to show a positive net present value to customers. This would be very challenging.”
Until that point Dominion had moved steadily, if ploddingly, ahead with plans to exploit Virginia’s offshore wind resources as a source of renewable carbon-free energy. The company had conducted a cost-reduction study in 2011, completed two internal transmission studies — finding that it could bring in up to 45 megawatts of offshore electricity to its Virginia Beach power grid without significant cost — spent $1.6 million in a blind auction to acquire offshore wind rights, and successfully solicited Department of Energy grants to help underwrite preliminary engineering and design on the two experimental turbines.
The disappointing $375 million bid threw a monkey wrench into Dominion’s rotor. Putting wind development on hold, the company convened in Richmond a gathering of dozens of stakeholders — from business vendors and partners to government officials and environmentalists — to deconstruct what went wrong and to plot a more cost-effective path to full-scale development.
“Dominion really wants to see his project move forward ,” said Mary Doswell, senior vice president of energy solutions, told the stakeholders. “We need to push our way through, and we need your help to do that.” While she did not say development of the larger offshore wind project would be stymied if the experimental turbines weren’t built, she didn’t deny it either. It’s not something she had thought about, she responded to a question. “We’ve been so laser-focused on this project that we haven’t considered what might happen.”
The experimental turbines would incorporate state-of-the-art technologies, never tested before anywhere else, that would affect the cost efficiency of a subsequent, large-scale wind development off the Virginia coast. The most feature important would be a hurricane-resilient design affecting the interaction of rotors and blades in high winds. While wind turbines operate in harsh weather conditions in the North Sea, where winds have been known to reach 90 miles per hour, turbines off the Atlantic Coast would be at risk of exposure to Category 3 hurricanes which generate wind speeds of up to 129 miles per hour. “It’s a very robust design,” said Mark Mitchell, the project construction manager.
The experimental turbines also would incorporate a new Alstom design for the drive train, and a twisted jacket foundation for the turbine. The turbines would be placed in a configuration that would enable Dominion to measure what kind of wind wake one turbine creates for another another — critical for determining layout in a wind field of 300 turbines. Additionally, Dominion would test remote monitoring technologies that would allow for predictive maintenance, such as replacing fatigued parts before they wore out.
Dominion expects to learn much else that would help it advance the 300-turbine project. For example, what are the seabed conditions? “You can’t just run a cable out there,” Mitchell explained. Hampton Roads is a major naval base. Is there unexploded ordinance on the sea floor? How hard is the seabed? What are the sand migration patterns? Ideally, the cable is buried a couple of meters underground. Dominion doesn’t want the sand to drift away and leave it uncovered. In a related matter, Dominion needs to know how deep to drive the steel piles underground to provide the needed stability for the turbine. More steel translates directly into higher costs.
Most of the feedback came from Dominion’s contractors and suppliers who helped put the bid together. Several main themes arose from the conversation. Continue reading