US could get low-cost clean hydrogen from offshore wind farms: Study

Offshore wind turbines can be used to produce clean hydrogen in the United States, according to researchers at the National Renewable Energy Laboratory (NREL).

In a paper published recently, the NREL researchers have put forth the claim that electricity from offshore wind turbines as one pathway to split water to produce clean hydrogen may make economic sense, especially along the U.S. Atlantic Coast and in the Gulf of Mexico.

According to them, the economics of hydrogen production from offshore wind turbines works perfectly in places where there are strong winds and the water is not too deep.

Clean hydrogen production from offshore wind turbines’ electricity

The goal of the U.S. Department of Energy (DOE) to produce clean hydrogen at a low-cost depends on the technology and the location of the production.

The DOE is looking for ways to bring down the cost of clean hydrogen made by electrolyzers to $2 per kilogram through the Hydrogen Shot initiative. This will make the hydrogen cost-competitive when compared to the more conventional carbon-intensive methods.

“Both offshore wind and clean hydrogen production are technologies that are rapidly evolving and when combined have the potential to generate and store a lot of renewable energy and decarbonize sectors that are hard to electrify,” said Kaitlin Brunik, a hybrid systems research engineer at NREL and lead author of the new paper.

The paper describes the use of case study simulations to analyze the techno-economics of producing hydrogen from offshore wind energy in 2025, 2030, and 2035, according to a release by NREL.

The research suggests that by 2030, a combination of factors including policy incentives and fixed-bottom offshore wind with onshore electrolysis may allow the production of hydrogen for less than $2 a kilogram.

Comparison of both scenarios

In the first scenario, an offshore wind plant generated electricity that was transmitted via high-voltage cables to an onshore site. There, an electrolyzer produced hydrogen from fresh water. This represented a conventional approach of pairing offshore wind with onshore electrolysis.

In the second scenario, the hydrogen was split from desalinated seawater at the offshore wind plant site, requiring more infrastructures in the ocean to accommodate the additional equipment. The hydrogen was then transported via pipelines to shore for storage. The researchers noted the technical feasibility of this scenario is less established.

“Moving an electrolyzer to an offshore platform for bulk energy production presents a novel challenge,” Brunik said. “To fully harness the electricity generated by offshore wind farms for hydrogen production, substantial electrolyzers are needed, along with ancillary equipment for water treatment, hydrogen storage, and transportation.”

Offshore renewable hydrogen production is an uncharted territory and it will require some new configurations to connect the necessary equipment with a wind farm for large scale operations.

“The researchers looked at shallower sites in the Gulf of Mexico and New York Bight where turbines could be fixed to the ocean floor, had abundant wind resources, and were in proximity to at least one of DOE’s Regional Clean Hydrogen Hubs that will connect hydrogen producers and consumers,” the release says.

“They also examined sites with much deeper waters off the coast of northern California and in the Gulf of Maine where the turbines would have to be installed on floating platforms.”

The paper was recently published in the Journal of Physics: Conference Series .