The offshore wind industry’s desire to push the boundaries of technology draws some interesting parallels to the early days of the offshore oil industry, and its subsequent progression into deepwater. The recent installation and connection of WindFloat Atlantic, the world’s first semisubmersible floating wind farm, in about 100 m of water, illustrates wind’s technological progression. This installation brings the total floating wind capacity to 66 MW, and it could grow to 19 GW by 2030 and possibly 70 GW by 2040, as more oil and energy companies with the relevant technical experience enter the market. It is also out of necessity that floating will be embraced, since there is a water depth limitation for fixed foundations; and wind resources tend to improve the farther out one goes from the coastline. It is worth noting that the water depth limitation for conventional monopiles and jackets or gravity-based structures is generally considered in the range of 60-80 m. Also, more than 80% of the offshore wind resources are in water depths of great than 60 m. Meanwhile, wind turbines are increasing in size and weight.
Offshore readers are aware of the early days of offshore oil and gas development, which started onshore and then ventured offshore in the 1940s. The industry then successfully conquered new water depths as the relevant technologies evolved. When development started to push the water depth threshold for bottom-supported rigs in the 1950s, a Shell-led team of scientists launched an R&D campaign for floating drilling and production systems. These efforts resulted in the first semisubmersible drilling unit, the Bluewater 1, built in 1962. The first oil and gas production from a floating platform began in 1975 from the Argyll field in the North Sea in about 80 m of water. Today, there are over 300 floating production platforms and moored hulls in up to 2,400 m of water.
The design of the world’s first commercial-scale floating wind farm, Hywind Scotland, is based on a spar buoy and moored to the seabed in about 100 m of water. Both Hywind Scotland and WindFloat Atlantic use technology originally developed for the oil and gas industry. Most of the upcoming floating projects are expected to use a spar or semisubmersible-based design, but the TLP, also derived from oil and gas, is a viable option as well.
Indeed, there are many differences between the design of a floating unit for wind and one for oil and gas, and this is not intended to suggest a path to commercialization and scale (a Carbon Trust-led JIP is releasing a series of reports on this topic). But wind’s progression from the “easier” and lower-cost opportunities, to the higher risk but potentially higher reward developments, does strike interesting parallels to the evolution of oil and gas development.