By Elizabeth Ouzts, Energy News Network

By year’s end, North Carolina regulators will issue their plan for how Duke Energy should zero out its carbon emissions, shaping the profile of the Charlotte-based utility’s electricity generation over the next three decades.

In the lead-up to the release of the Carbon Plan — a requirement of a bipartisan state law that passed last year — the Energy News Network is spotlighting some of its most hotly contested aspects.

Earlier this month, we explored how advocates believe Duke should double down on solar and examined the company’s controversial bid for a new generation of gas plants. Last week, we homed on energy efficiency.

Today, our focus is wind power, especially offshore. While ocean-based turbines hold tremendous promise for delivering carbon-free electrons, bringing them online can take a decade or more, and their high costs cut against state regulators’ mandate to achieve a least-cost pathway to net zero. 

‘A proven technology’

North Carolina is home to the Southeast’s first and largest land-based wind farm: over 100 turbines scattered across farmland near the Virginia border that supply Amazon data centers. A second project is in the permitting stage and could begin delivering power at the end of next year.

Yet by far, most of the excitement around wind power in the state is offshore.

Enormous turbines with towers 30 stories high can harness more energy than their land-based counterparts and have the potential to power the state many times over. Ocean winds that blow most powerfully in winter mornings and summer evenings can serve as a perfect complement to solar panels that aren’t productive in those hours.

And while U.S. Energy Information Administration data show offshore wind is among the most expensive forms of energy today, those costs are expected to plunge as more specialty parts like cables and blades are produced in the United States rather than shipped from overseas. The local manufacture and assembly of these components could also create vast economic opportunities.

That’s part of why Gov. Roy Cooper, a second-term Democrat who helped draft the law requiring the Carbon Plan, has made promoting offshore wind a priority. Last June, he issued an executive order calling for 2.8 gigawatts of wind energy off the North Carolina coast by 2030 and 8 gigawatts by 2040 — enough to power 2.3 million homes.

Yet, of the four pathways Duke proposed for carbon neutrality, none come close to these levels. The company’s most aggressive pursuit of offshore wind shows 1.6 gigawatts by 2032 and 3.2 gigawatts by 2050. Two pathways show just 800 megawatts by midcentury. And one, which heavily relies on the build-out of small nuclear reactors, shows zero.

It wasn’t just Duke. Synapse Energy Economics, which modeled alternative pathways to net zero carbon for a coalition of clean energy advocates, also showed a maximum of 800 megawatts of offshore wind by 2050. The results show the difficulty of projecting costs well into the future, said Tyler Fitch, a senior associate at Synapse who performed the modeling.

“We have good reason to think that as the technology matures, and deployment matures, we will see more economic offshore wind,” Fitch said. “But with so little data, it’s difficult to project the cost trajectory and the availability.”

Katharine Kollins, the president of the Southeastern Wind Coalition, acknowledges that, for now, the high price of offshore wind works against it in the Carbon Plan. But, she adds, that’s partly because ocean-based turbines are compared to not-yet commercially available resources like hydrogen and small nuclear reactors. 

“There’s just such a huge question mark on those technologies, where there’s not on offshore wind,” Kollins said. “We know that offshore wind is a proven technology. We know that it adds a lot of value to the grid.”

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‘Planning to build out these resources’

The Carbon Plan is due to be refreshed in 2024 and every two years after that, and offshore wind proponents believe the economics will keep getting better such that more and more can be included with each iteration. The question, they say, is what should be done now to prepare.

“Let’s make sure we’re planning to build out all of these resources that we know are going to be needed,” Kollins said.

Wind developer TotalEnergies is the most aggressive on this score. The wind energy area known as Carolina Long Bay could represent between 2 and 3 gigawatts of capacity, according to the company, which owns half of the parcel, about 20 miles off the state’s southern coast.

“It is reasonable to select and set a development goal of 2.8 gigawatts for the long-term resource class of offshore wind production by 2030,” says Total in its proposed order to utilities commissioners. Duke, the company proposes, should “plan its transmission facilities to receive and transmit the output equivalent to 2.8 GW of offshore wind generation.”

Duke, whose unregulated renewables company owns the other half of Carolina Long Bay, is focused almost exclusively on that parcel, arguing that it should take ownership of the lease and begin developing it apace. “The proposed path does not foreclose other options,” the company says in its proposed order, “rather it ensures [we] will have at least one offshore wind project available in the 2024 Carbon Plan update.”

Advocates and the clean energy industry, however, question whethe