Offshore wind power is a renewable energy source powered by wind gusts in the ocean. Wind farms made of many wind turbines use the offshore wind to generate electricity. Underwater electrical transmission lines send power to the shore. It is hooked up to the existing onshore electrical grid and distributed to consumers like you.
Benefits of offshore wind?
Offshore wind in the ocean or other bodies of water is typically at a higher speed and more consistent than wind over land. Think about where you may live and how often you feel strong wind, and compare this to the last time you were at the beach or on the coast. Which was stronger? Offshore wind turbines can more effectively convert this stronger wind to electricity at a larger scale than onshore wind turbines. The number of places with sufficient wind to economically produce power is limited, so most offshore wind development occurs at scale in offshore wind farms.
History of offshore wind
While onshore wind has been used for centuries, offshore wind farms are much newer. The first offshore wind farm is the Vindeby in Denmark, and it was built in 1991 by the company Orsted and served three decades. This project had enough capacity to power about two thousand households.
How does an offshore wind farm work?
While the process is very complicated with many different parts and steps, a simple guide to wind farms is:
- The wind turns the windmill blades that are connected by a shaft to a generator
- The generator transforms the kinetic energy from the blades into electricity
- The electricity flows from the generator to an electrical substation via underwater transmission lines
- The substation aggregates and changes the voltage of the power and transports it to the grid
The difference between Onshore and Offshore Wind Farms
Onshore and offshore wind farms are very similar in that both convert wind power to electricity. The main differences are due to an offshore installation’s construction, maintenance, and safety considerations.
Offshore wind farms are in the middle of bodies of water, sometimes in deep ocean water. The construction company will need to use high-technology products and services onshore, which may not be possible. An example is the transportation of the giant blades since many blades may be too large to travel on land roads, and they can easily fit on construction vessels.
Environmental impact of offshore wind farms
Since offshore wind projects are typically in protected waters, they undergo strict regulatory filings with local authorities. Contractors can only bid tenders in the offshore wind farm business if they can operate safely.
While an offshore wind farm produces clean, renewable energy, they also affect the local environment in which they are installed. Ensuring the local environment is not affected by the facility is essential, including all project phases like laying cables.
Types of offshore wind projects
There are two types of offshore wind farms, and the main difference is the type of foundation securing the turbine.
- Fixed foundation
- Floating foundation
Fixed foundation turbines
A fixed farm has a turbine installed on a fixed foundation. These are the most common foundations as they have been used the longest. There are three main types of fixed foundations:
- Monopile
- Jacket
- Gravity
Each fixed foundation has an ideal operating and installation condition based on the project.
Floating foundation turbines
Floating foundations are a newer technology for offshore wind projects. These have a higher cost than fixed, yet they can generate more power since they can hold larger blades. Construction of floating foundations occurs at the dock. Then they are transported out to the location when ready to be installed.
What countries have offshore wind power
Only countries with water access can have offshore wind, meaning no landlocked countries can participate. Thankfully for Europe, most of their countries have ocean coast access. While many countries have wind farms, here are some that have a significant amount of offshore wind farm businesses:
- United States (USA)
- United Kingdom (UK)
- Germany
- Japan
- China
- Denmark