Offshore Windfarm Projects - Distance to shore. Source: Air & Sea Analytics, Offshore Wind Rotorcraft report, published 2021.
A marine-Focussed Industry
The maintenance of offshore wind farms is a people-intensive ongoing process. Given the presence of rotating equipment in a marine environment this is hardly surprising but as the offshore wind business expands, the debate about how best to transfer people to work continues.
The offshore wind industry is ‘marine-orientated’ and has historically favoured vessels for crew transfer. Early offshore windfarms were close to shore, usually less than 10km away, visible from land, and vessels were ideally-suited and the obvious solution for getting to the turbines. Logistics hubs for servicing turbines naturally became located at or nearby ports. There are now nearly 500 vessels marketed for the servicing of offshore windfarms.
However, windfarm projects are moving further from shore - by 2030 nearly half (48%) of the installed base of turbines will be more than 30km offshore. The available data on windfarm operations tell a clear story: The helicopter is faster, safer for the passengers and less harmful to the environment than a crew transfer vessel whilst being less susceptible to interruption in service through bad weather.
Whilst the difference in speed is plainly obvious, the safety and environmental concerns are less intuitive. Modern helicopters and the operations and safety culture of leading rotorcraft operators are very safe and as industry data confirms (1), heli-hoists cause far-fewer recordable injuries or lost time incidents compared to crew transfer vessels (CTVs).
As far as emissions are concerned, CTVs emit more CO2 per passenger mile than any comparable rotorcraft operation(2). Whilst some public domain comparisons have not necessarily been fair (eg. most-polluting CTV vs least polluting helicopter operation) our analysis in the recent Offshore Wind Rotorcraft report showed that for both crew transfer operations (shore to helipad) and heli-hoisting (to the turbine nacelle) the helicopter had a clear advantage.
Helihoisting to a wind turbine (stock image)
Data Visualization showing operational windfarms, vessel movements and helicopter flights. Data sources: Air & Sea Analytics, MarineTraffic Satellite AIS, FlightRadar 24.
Although the vast majority of transfers offshore still occur via vessels, as can be seen above in a 24hr view of activity around the Humberside area on the east coast of the UK, the offshore wind rotorcraft market has emerged as a new application for modern performance class 1 helicopters in recent years, boosting demand for aircraft such as the AW169, H135 and H145. Larger aircraft including the AW139, H175, AW189 and S-92 have also been used to transfer crew from shore to offshore helipads.
A GROWTH SECTOR FOR ROTORCRAFT AND NEW VESSEL TECHNOLOGY
The offshore wind business is evolving to address the emissions issues of the CTV and hybrid/battery powered vessels or even hydrogen-fueled vessels have been proposed and in some cases built. However, these are few and far between. Of the 480 offshore wind service vessels we are tracking via satellite AIS data, almost all are traditionally-fueled vessels. Offshore wind rotorcraft are growing in number and at any one time as many as 30 are active in the market presently. We expect nearly a hundred additional aircraft to be active in offshore wind by 2030.
Leading OEMs in the offshore wind rotorcraft market are Airbus and Leonardo. Leading lessors such as Milestone, Macquarie and LCI all either have active aircraft in the market or have had in the recent past. In the UK Unifly and CHC are operating offshore wind flights in the area shown above and Wiking are operating from Wick in Scotland whilst in mainland Europe Wiking, Heliservice, HTM and NHV are all prominent players. Ad-hoc construction support work is becoming more common, for example last month Heli Holland provided an H175 for crew transfer support to Van Oord in France for the Saint-Brieuc offshore windfarm project.
Offshore windfarm operators have a choice to either embrace aircraft in offshore wind operations (notably a number of the leading OEMs and operators such as Vestas, Siemens and Vattenfall now employ dedicated aviation specialists) or to try and force change on the marine business to provide safer, cleaner operations.
The uptake of larger ‘service operations vessels’ (SOVs) and ‘walk-to-work’ systems is a key driver in improving offshore vessel safety. CTVs are not able to operate beyond 1.5m significant wave height whereas a larger SOV will provide both greater availability (to at least 3m significant wave height) and lower risk of injury. SOVs are typically stationed on-site with on-board accommodation and hotel facilities and as seen in the data do not return to shore each day.
The SOV is an attractive maintenance and construction support (CSOV) option but also provides an opportunity for the vessel to remain offshore ‘on-station’ for extended periods of time through changeout of crew with rotorcraft via helipads. This combination of vessels and rotorcraft may ultimately prove a popular solution for safe, reliable and easy transfer from airport to wind turbine.
We follow the sector as it develops with continuing interest.
Steve Robertson
15th September 2021
The Offshore Wind Rotorcraft report was published in 2021 by Air & Sea Analytics. The report explains the drivers of demand for this important sector, builds a forecast of future activity based on a granular project-by-project analysis and translates this to demand for rotorcraft. The report is ideal for stakeholders in the energy rotorcraft sector. Click here for more information.
Footnotes:
(1) G+ Global Offshore Wind Health and Safety Organisation data reviewed for the recent Offshore Wind Rotorcraft report show a Total Recordable Injury Rate for helicopters operations of 0.04 per million man-hour vs 0.64 for CTVs.
(2) A light medium helicopter used for heli-hoisting with six passengers emits 0.08t CO2 per passenger per 100km whereas a CTV emits between 0.10t to 0.15t CO2 per passenger per 100km. (source: Offshore Wind Rotorcraft Report, Air & Sea Analytics 2021. Inputs to the analysis were checked/verified with both relevant OEMs)