A 1-MW vertical axis wind turbine could change offshore windfarms forever

SeaTwirl’s wind turbines.

SeaTwirl 

A Norwegian yards group, Westcon, has put in place an agreement with Sweden-based company SeaTwirl to deploy 1MW vertical axis wind turbines in the North Sea by next year, Recharge News has reported. This commercial scale vertical axis turbine could kick off a new era in offshore wind farms delivering cost competitiveness very soon.

As the world pushes for a shift towards renewable energies, there is a lot of interest in tapping the potential of ocean winds. Different methods have been attempted to harness this energy, but the conventional wind turbine is the one that has been making much of the headlines.

The recently operational Hornsea 2 project off the coast of the U.K. is currently the world's largest offshore wind farm. However, as turbines used in such projects get bigger, the cost-effectiveness of the platform is expected to drop since the construction costs will balloon as we go deeper into the seas.

Vertical axis wind turbines can be packed densely in an offshore windfarm

SeaTwirl 

Vertical axis wind turbines

The vertical axis wind turbines (VAWTs) offer a slew of advantages over conventionally used horizontal axis wind turbines (HAWTs). The latter relies on sophisticated instruments that tell them in which direction the breeze is flowing in and where to point themselves for maximum power generation. The turbines of a VAWT can harness power from all directions, so they can work without such equipment.

Since all the components of a HAWT need to be assembled together atop, towers that hold them need to be strong and built with huge counterweights. Going forward, this requirement will only increase, further increasing the costs of making them. The turbines create minimal wake effect downwind and, therefore, can also be placed closer together in the wind farm.

SeaTwirl's next-generation VAWT

SeaTwirl has been engaged in making VAWTs since 2012, and its 43 feet (13 m) high prototype turbine has been generating power for the past seven years. The simple design consists of three turbines mounted on a buoyant pole that has a heavy bottom that serves as the keel. As the turbine catches the wind, the entire pole spins, and the generator housed below generates power.

Now, the company has unveiled its next-generation turbine, which it describes as 30 times the size of its prototype. Dubbed S2x, the turbine pole will rise 180 feet (55 m) above the water surface while plunging down to a depth of 262 feet (80 m). The turbines are designed to automatically cut off power generation when wind speeds exceed 56 miles an hour (25 m/s), although they can withstand speeds up to 112 mph (50 m/s), a category two hurricane, New Atlas reported.

Each turbine has a power generation capacity of 1 MW, and the company claims that its Levelized Cost of Energy (LCoE) will be lesser than US$50 / MWh, bringing it at par with onshore wind projects.

Westcon plans to deploy the first S2x in the country by 2023. The turbine will be tested for a period of five years, following which SeaTwirl has plans to scale up its turbines in the 6-10 MW range first and then to the 30 MW range.