Wind energy has been proven to be a reliable and efficient source of renewable energy due to its simplicity of using wind and easy conversion to electricity. With consistent improvements in wind turbine and installation technology, the offshore wind sector has the capacity to expand even greater. Since the beginning of 2022, wind power can generate more energy than coal or nuclear power. Offshore wind farms can be installed in spaces humans aren’t occupying, allowing for bigger turbines to provide consistent and higher energy outputs, with more predictable wind patterns and speeds.
The history of wind energy starts in 1980, with 20 onshore turbines generating 0.6 MegaWatts (MW) of electricity in New Hampshire, powering approximately 150 homes then (powering about one home today) and replacing energy that would have been generated from 5,000 barrels of oil. 11 years later in 1991, the first-ever offshore wind farm with 11 turbines was installed in Denmark generating 5 MW of electricity, which is enough to power 2,200 homes. The largest offshore wind farm today is Hornsea Two, located off the Yorkshire Coast in the United Kingdom, with 165 turbines, generating 1.3 GigaWatts (GW) of electricity to supply 1.4 million homes.
With technology constantly developing, offshore wind could be spinning out of control, but in the best way possible. A recent research article by Hugo Díaz and Carlos Guedes Soares reviews the current status and technology for offshore wind and describes the future trends of what offshore wind could look like.
Offshore wind was originally seen as impractical and hard to achieve, since installing turbines in the ocean would require lots of effort and if it was successful after construction, the maintenance and weather conditions would break them down. But since 1991, there are over 162 offshore wind farms built worldwide in 53 different countries (most are still functioning) and there are plans for more offshore wind turbines to be built, like the Changfang Xidao offshore wind farm off the coast of Changhua, Taiwan. The current offshore wind farms have the capacity to produce 55,585 MW of electricity and the trend is only going upwards.
Several countries followed the offshore wind farm trend, as they were big fans of this new development. Europe and Asia are major contributors to the current offshore wind production. Currently, the leader of the offshore wind industry is China as they came, spun, and conquered the trendsetter of the industry, Denmark, generating about one-fourth of the total offshore wind energy production.
The installation process for an offshore wind farm involves exploring and surveying the area, complying with environmental regulations of the area, getting the required vessels for installation, prepping the seafloor for construction, installing the base for the turbine, and lastly, installing the wind turbine. There are several different choices for offshore wind turbine bases and depending on the type of seabed the offshore wind turbines are installed in, certain bases will be more beneficial than others.
Different types of wind turbine foundations, Ocean Engineering June 2022
After these bases have been installed, the main stem of the wind turbine can be installed, then the blades. During the installation process, the energy of the wind turbines needs to be somehow collected and transferred back to land and into the grid. Using thick, underwater wires, the turbines will be connected to a substation which will then connect back to the shore to collect all the energy generated from the turbine.
When the first onshore wind farm was installed in 1980, each turbine was about 18 meters tall. Now, wind turbines have increased in size, ranging from 165 – 200 meters in height and 135 – 170 meters in rotor diameter. Offshore turbines now can be installed at several different distances, depending on the composition of the sea floor. Trends from 2020 predict to see turbine heights to increase by 19% and rotor diameters to increase by 23% within the next decade.
Currently, offshore wind farms in Asia tend to be closer to shore (averaging around 10 kilometers) while farms in Europe are farther (averaging around 53 kilometers). As the distance from shore increases, the depths in which turbines are installed also increase. Asian farms currently average around 12 meters in depth while European farms average around 31 meters in depth. These values are predicted to increase over time as technology advances to allow us to install farms even farther away from shore.
Evolution of farm distance to shore and depth, Ocean Engineering June 2022
The current largest functioning turbine is located in the Hornsea Two wind farm, 89 kilometers away from the coast of the United Kingdom. It stands a little over 200 meters tall, has a rotor diameter of 122 meters, and has a capacity of 11 MW. With the current improvements in science and technology, future turbines would be able to be larger and generate more energy. Turbine model MySE 16.0-242, is currently in its prototyping stage and plans to be installed in 2024, standing at 264 meters tall, with a 242-meter rotor diameter, and a capacity of 16 MW (enough to power 20,000 homes).
Range of turbine rotor diameter and height with wind farm numbers, Ocean Engineering June 2022
The future of offshore wind, as stated in the article, seems to be spinning in a positive direction and with climate change posing a great danger, the transition to renewable energy is essential. Future trends predict farm sites further from shore, be installed in deeper waters, increase in height and rotor diameters for each turbine, and will include more countries installing offshore wind farms. Offshore wind has shown so many benefits in its energy generation and availability of installation spaces, and more countries are following the transition to offshore wind.