Helicopters will underpin US offshore wind development

Carbon footprint

In addressing the carbon footprint of helicopter operations, Mr Freiland shared environmental data comparing a 24-passenger CTV with a 12-passenger AW139 helicopter — both serving a windfarm some 50 nautical miles offshore. CO2 emissions for the CTV were 3.66 tonnes per 100 km, while they were 0.55 tonnes per 100 km for the helicopter. On a per passenger basis, the helicopter also shined, with 0.05 tonnes per 100 km compared to 0.15 tonnes per 100 km for the CTV.

If the availability of green fuels such as hydrogen emerge in the CTV, this would change the comparison completely, he admitted, as helicopters will be using aviation kerosene for a long time to come.

The first hydrogen-powered CTV, Hydrocat 48, was introduced by Windcat Workboats and CMB.TECH for operation with Vestas in 2022. The CTV won OSJ’s Offshore Energy Vessel of the Year Award in 2023. Windcat Workboats plans to introduce six other hydrogen-powered CTVs in 2024.

Better safety

According to statistics shared by Mr Freiland, helicopters have substantially better safety records, with total recordable injury rates of 0.04 compared with 0.64 for CTVs.

From an environmental aspect, helicopters have an advantage, too, according to Mr Freiland.

HeliService USA signed the first-ever agreement to provide helicopter crew transfer and hoisting operations for US offshore wind farms with Ørsted and Eversource, commencing operations in June 2023. Utilising Leonardo AW169 helicopters, HeliService USA will support the construction of South Fork Wind, Revolution Wind, and Sunrise Wind in the Northeast. HeliService USA is a veteran-owned small business that has partnered with Germany’s HeliService International to represent its brand in the US. This allows to bring more than 30 years of experience in commercial aviation, including crew transfer, hoisting, cargo transport, and helicopter emergency medical services (HEMS) to the US market.

Leonardo and Airbus helicopters are a common sight at offshore windfarms in Europe to maintain wind turbines. The helicopters use hoist systems to lift wind technicians to and from the top of wind turbines. Noting this is a well-proven operation, Mr Freiland said the company has safely performed 23,000 hoist cycles. “This is no MacGyver-type operation,” he said, adding, “We are paranoid about safety.” Passengers and helicopter operators receive special training and certification for this type of transfer operation.

While making a strong business case for helicopter use, Mr Freiland admitted developers had to weigh a number factors before deciding when, where and whether to use rotorcraft. “You cannot say helicopters are always the (right) option.” HeliService International also provides crew and cargo transfer via vessel.

Faster travel times to windfarms offered by helicopters also increase productivity. One of the factors in deciding on the use of helicopters as opposed to CTVs is the impact of utilisation on your personnel, noted Vestas aviation specialist James Davis. This could come into play in the US where there are vessel speed restrictions imposed to reduce the risk of whale strikes where windfarms are sited. Helicopters, of course, are not restricted by such speed restrictions, and have little or no impact on marine life, according to Ørsted lead aviation specialist Lars Munch.

All vessels 19.8 m or longer must travel at 10 knots or less in certain locations (called Seasonal Management Areas or SMAs) along the US east coast at certain times of the year to reduce the threat of vessel collisions with endangered North Atlantic right whales.

Mr Davis noted more data from OEMs on the reliability of new-generation wind turbines to plan for wind turbine maintenance operations. Reliability would impact the number of flights needed to maintain proper maintenance protocols.

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