Offshore Wind

Floating offshore wind is the latest advent in renewable energy technology. Today, around 80% of the world’s wind resources are in waters deeper than 60-70 meters and are unsuitable for bottom-fixed foundations. But floating offshore wind provides a solution to harness this untapped energy with installations where the water is deeper and the winds are stronger.  

Floating offshore wind incorporates giant turbines which can be nearly as tall as the Eiffel Tower on floating steel or concrete platforms which are attached by anchors to the seabed. The larger the turbine, the more power it can produce. Floating offshore wind farms can make massive contributions to the energy grid, powering millions of homes and businesses on shore.  

When the wind makes the blades on a turbine spin around, electrical power is generated and transported through cables to a nearby substation. From here, the power is transported to the electrical grid on land.

Floating wind turbines are mobile – meaning they are constructed on land and the equipment is installed quayside before being towed to an offshore location. The turbines are then hooked up to mooring lines, which are fixed to the seabed by anchors, ensuring the structure remains stable on the surface, whatever the weather. For example, Principle Power’s floating semi-submersible platform has withstood waves as high as 17 meters off the coast of Portugal.

Bottom-fixed turbines are turbines that are assembled on fixed foundations that are placed on the seabed and located in shallow waters up to 60-70 meters in depth.

Improvements and innovation have allowed for an increase in turbine size which means each individual turbine can produce more electricity. Today, turbine producers have introduced turbines to the market that can produce up to 15-16 MW. The next generation of wind turbines are expected to produce up to 20 MW.

There are many benefits to floating offshore wind, including:  

• Accessing the best wind resources  

The turbines can be installed far out to sea where the winds are strongest, producing more energy and providing security of supply. Reaching untapped energy resources will help deliver Net Zero and carbon reduction ambitions.  

• More space to build at scale  

Building at scale reduces the costs of generating electricity, ultimately driving down prices for consumers. At deep waters, the very largest turbines can be used, allowing for dramatically increased energy production  

• Less visual impact  

Because floating offshore wind farms are so far out to sea, this reduces any visual impact.  

• Smaller environmental footprint   

Floating offshore wind has a smaller environmental footprint and the wind farms can be kept away from bird-feeding grounds or migration routes.  

• Supports local content  

Installation requires a local supply chain, generating new green jobs and supporting local economies.  

• Operational benefits  

Because floating foundations can be assembled quayside, this increases efficiency, reduces the need for heavy lift vessels at sea, and decreases the risk of delays.   

• Less conflict with fisheries and other ocean users  

With a very broad envelope of suitable water depths, floating wind can be kept away from important fishing grounds or areas of material importance to other ocean users.

• Location closer to load centers 

Many costal load centers and cities around the world have water depths incompatible with bottom-fixed foundations. Floating wind enables access to energy sources closer to our cities better matching generation with demand, having positive effects on the grid and lessen the need for new infrastructure. 

80 percent of offshore wind resources are in deep waters, which is defined as water deeper than 60-70 meters. As simple bottom-fixed foundations are not viable in water depths deeper than 60-70 meters, more effective deepwater structures, especially floating designs, are critical to unlocking further energy production.  

Floating offshore wind technology allows us to locate wind farms where the wind conditions are best for producing renewable energy.  

Markets are emerging in several countries around the world, all seeking to capitalize on the extraordinary potential.  

Floating offshore wind is flourishing where developers are able to work proactively with decision-makers, administrators, and stakeholders to create a regulatory framework that is supportive and engages with global and local supply chains. In many areas, this has been undertaken with a view to reskilling workers from the fossil fuels industry to support growth in the renewables sector.  

Developing floating offshore wind farms starts with a commercial bidding process for the leasing of the seabed, usually led by national governments or their agencies. Through a tendering process, developers like Mainstream apply or bid for site exclusivity and the successful applicants then pay ‘option agreements’ to reserve the rights to specific areas of seabed.  

Full seabed leases are granted at a later stage once applicants have all the necessary consents. This includes approval from regulators, delivering the financing and making a final investment decision (FID), going through the planning process, securing grid connections, and agreeing a Power Purchase Agreement (PPA) between the producer and a customer for the sale of the electricity.  

Once that process is complete, the operational side can commence. The wind farm must be developed and constructed in accordance with sustainability and safety frameworks, with sites chosen, workers hired, and supply chain agreements in place. Once operational, a floating offshore wind site has a lifespan of around 30-35 years with continuous maintenance, before decommissioning takes place and materials are recycled.   

Hydrogen is an abundant substance and the most common substance we have. Pure hydrogen (H2) in natural form is uncommon and important sources of hydrogen are from natural gas and electrolysis of water. Hydrogen has a fundamental role in many industrial processes and, importantly, has the potential to displace large quantities of fossil fuel like coal and gas through more extensive use. Hydrogen is one of many energy sources that can help reduce global carbon emissions and has a wide range of uses – from road transport to aviation to home heating. Numerous industries can make use of hydrogen, but two of those most frequently mentioned ones are fertilizer production and iron. However, it requires energy to make hydrogen in the first place.   

The process of making hydrogen is described using different colors, such as blue, grey and green hydrogen. Green hydrogen, which is the cleanest option, involves splitting water by electrolysis to generate only hydrogen and oxygen – and no harmful by-products. Significantly, the energy to power that electrolysis comes from renewable energy sources, such as offshore wind.  

Offshore wind can therefore be a great source of high energy that is needed for the electrolysis process of making hydrogen. It also does not require connection to the electricity grid, which can accelerate the development of offshore wind.