Offshore wind energy is a form of renewable energy that uses wind turbines to convert kinetic energy into electrical power. These turbines are placed in offshore areas, typically in the ocean, to take advantage of the strong winds that are present there.
Offshore wind farms can generate significantly more electricity than onshore wind farms, and they have the potential to play a significant role in meeting global energy needs. This blog post will discuss what offshore wind energy is, how it works, and possible advantages and disadvantages of its use.
How Do Offshore Wind Turbines Work?
Thanks to the blades’ aerodynamic design, when wind passes through them, it causes the blades to rotate.
This rotation is transferred to a low-speed shaft inside the turbine connected to a gearbox.
The gearbox increases the rotational speed of the shaft, which then powers a generator to create electrical power.
A converter is then used to transform the generator’s direct current (DC) output into alternating current (AC), which is then fed into an onshore transformer via undersea cables.
The transformer increases the voltage of the AC before it is fed into the power grid, where homes and businesses can use it.
Types Of Offshore Wind Turbines
1. Gravity Based Foundation (GBF)
This foundation uses a large concrete or steel structure to support the turbines, similar to the technology used in offshore drilling rigs.
Tugboats are used to tow the GBF to its location, where it is then sunk to the seabed using ballast material such as rocks or gravel to improve the stability of the wind turbine.
GBF foundations are typically less expensive than other foundation types but are only suitable for shallow waters.
2. Monopile Foundation
A monopile is a large, single-cylinder driven deep into the ocean floor.
This type of foundation is cost-efficient, easy to install, and works well in sand and gravel soils, so they are often used in areas with shallow water.
The drawback of this type of foundation is that the installation process creates a lot of noise and pressure waves which can harm marine life.
Additionally, wind and waves can accelerate the structure’s fatigue damage, which reduces its lifespan.
3. Tripod Foundation
A tripod foundation is similar to a monopile, but it has three legs connected to a large base.
This design provides extra stability, making it a better choice for areas with high winds and rough seas.
One problem with this design is that it may need to scour protection around the tripod when the bottom current is strong.
4. Jacket Foundation
Similar to offshore oil platforms, this foundation is a lattice-truss structure with three or four tubular legs linked by diagonal struts.
This foundation can be used in a wide range of water depths and can be easily transported and installed due to its lightweight.
Additionally, they are very stable, durable, and easily withstand high waves.
5. Floating Foundations
Floating foundations are becoming increasingly popular due to the advancements in technology and growing demand for offshore wind energy.
These foundations consist of a buoyant structure tethered to the seabed using cables or chains.
Floating foundations can be installed in deeper waters where other types of foundations are not feasible.
The main drawback of this type of foundation is the high installation costs.
What Are The Advantages Of Offshore Wind Turbines?
- Increased energy production – Offshore turbines have the potential to produce more energy than onshore turbines due to their location in areas with higher wind speeds.
- Reduced environmental impact – Offshore turbines do not take up valuable land space, and they do not have a significant visual impact on the landscape.
- Increased safety – Offshore turbines are located away from populated areas, so there is no risk to human health or safety in case of an accident.
- Reduced noise pollution – Offshore turbines are located far enough from shore that they don’t produce any significant noise pollution.
- Reduced risk of bird strikes – Offshore turbines are located away from areas popular for birds, so there is a reduced risk of bird strikes.
What Are The Disadvantages Of Offshore Wind Turbines?
- High initial cost – The initial cost of building offshore turbines is much higher than for onshore turbines.
- Difficult to maintain – Offshore turbines are located in difficult-to-reach areas and can be expensive.
- Impact on marine life – The construction and operation of offshore turbines can impact marine life, including fish, mammals, and birds.
- Potential for conflicts – Offshore turbines cause confrontations between groups, such as fishermen, boaters, and environmentalists.
- Risk of accidents – There is a risk of accidents occurring during the construction and operation of offshore turbines. Examples of accidents include collisions with ships, fires, and turbine failures.