The offshore wind energy community has experienced an evident expansion in recent years as more people seek renewable and reliable energy sources. Even better, many offshore wind turbine technologies are evolving and becoming more affordable, which explains why more countries are considering adopting the technology to reduce the environmental impact of conventional energy generation.

How are offshore wind turbines installed?

Offshore wind turbines construction is an activity in which engineers assemble several wind turbine parts and finally connect them to the grid. Since the activity occurs offshore, it is considered a marine operation with many challenges, including safety risks in lifting operations, weather windows, marginal installation equipment in the market, etc.

Installation equipment and vessel

The engineering challenges of offshore wind turbine installation have led to the development of specialist machinery and innovative construction techniques. According to de website of IQIP, a leading global supplier of offshore wind turbine installation equipment, the selection criteria of vessels is usually based on various reasons, including wind turbine technologies, budget for installation tasks, and market availability.

For instance, tugboats are the most economical and are used to tow floating foundations or non-self-propelled barges. It maneuvers other vessels by pulling or pushing them through a tow line or direct contact.

Jackup barges and crane barges are used in lifting preassembled wind turbines and structures during installation since lifting operations require high-capacity cranes. Generally, an offshore wind turbine installation project cannot be accomplished without special equipment. The equipment is used in transport and installation scenarios based on its capability.

The installation process

The engineers construct the wind turbines onshore in a kit form in separate sections, including the tower sections, base, turbine blades, and nacelle, which holds the generator. Then they assemble the components at sea to construct the turbine. These components are then transported and assembled on special sea jacking ships, purpose-built and can jack themselves out of the water providing a stable platform to facilitate precision lifting.

The ships also carry hydraulic rams used to install the wind turbine foundations. A monopile may be used to secure the wind turbines into the sea bed. Note that monopiles are one of the standard foundation designs for offshore wind energy installations owing to their easy installation in shallow and medium depth waters.

When the monopile is set into the sea bed, a transition piece is slowly lowered into position and secured as it plays the role of linking the turbine and the monopile. The next step involves assembling the turbine tower, and the engineers crane it into position then bolt it together. After attaching the tower pieces, the nacelle is attached on top and the generator connected, and the final stage is connecting every turbine blade to the hub on the nacelle.

After fully assembling the turbine, the pitch angle and yaw of the blades can be adjusted accordingly to maximize its performance. Then every wind turbine is linked to the offshore substation that feeds into the national grid.

conclusion

Offshore wind turbine installation is not a straightforward process anyway, and it involves a lot of engineering expertise and resources to accomplish the project.