To reach net zero by 2050 and meet global climate targets, the world needs to scale up renewable energy generation at a rate never seen before. A large chunk of this energy mix will need to come from offshore wind. The UK has been an offshore wind advocate for over a decade. In April 2022, the British Energy Security Strategy set a target of reaching 50GW of offshore wind by 2030. The next big development, needed to help reach this target, is the industrial scale-up of floating offshore wind, which will constitute 5GW of this 50GW target.
Floating offshore wind farms are different from the more established, fixed bottom sites. Instead of turbines attached to monopiles or jacket foundations fixed into the seabed, turbines are placed onto floating platforms and anchored to the seabed via mooring lines. These are best suited to deep waters, where fixed farms are impractical. This technology enables offshore wind to become a power source for countries or regions previously limited by water depth. In the UK alone, this could see commercial scale farms off the coast of the South West of England, Wales, Northern Ireland, Scotland and the Northern North Sea.
The Carbon Trust has been involved with the UK’s offshore wind industry since its inception. In 2016, the Carbon Trust set up the Floating Wind Joint Industry Programme, or Floating Wind JIP. This is a collaborative research and development initiative, bringing together 17 leading international offshore wind developers. The primary objective is to overcome technical challenges and investigate opportunities for the deployment of large-scale commercial floating offshore wind farms. The programme is technology-focused, with a particular emphasis on large-scale deployment, de-risking technology challenges, identifying innovative solutions and cost reduction.
The Floating Wind JIP has so far completed two stages of work. Back in 2016, Stage 1 undertook initial feasibility studies targeting three key topics: policy and regulation, cost sensitivity analysis, and technology risk. Stage 2 undertook more detailed assessments of key technology challenges common to multiple floating wind concepts and supported innovation to develop the solutions needed for deployment of large-scale floating wind arrays. The Floating Wind JIP is currently in Stage 3, which will build on this previous work to accelerate technology development for large-scale commercial deployment of floating wind.
There is a long road ahead to scale floating wind to deliver the kind of energy output targets outlined in the British Energy Security Strategy. But it’s also worth reflecting on how far this technology has come to get to where we are now. The first floating wind turbine to scale from a conceptual to operational phase was the Hywind 1 project, off the coast of Norway in 2009. Following this, and after nearly a decade of refinement, in October 2017 Hywind Scotland, the world’s first floating wind farm was commissioned. This site consists of five turbines off the coast of Peterhead in Scotland, each capable of generating 6MW each.
There are currently more than 40 differing floating wind platform concepts under development, and new concepts frequently being announced. Examples of these include the Kincardine and Wind Float Atlantic projects utilising semi-submersible platforms and Hywind Scotland utilising spar-type platforms. Hywind Scotland has achieved the highest average capacity factor of all offshore wind farms in the UK. This demonstrates that floating wind can perform as well as, and better than, bottom-fixed offshore wind.
As the prevalence of wind farms has increased, so has the size and capacity of turbines. For example, the Siemens Gamesa SG 14-236 DD turbine has a 43,500m2 swept area, approximately the size of 6.1 standard football pitches. A single turbine of this type can generate enough electricity annually to power 18,000 European homes for a year. In the next five years, we expect significant technology development in floating wind to reduce cost, scale production, and broaden applicability. Current models suggest floating wind may become cost-competitive with other energy technologies by 2030.
While fixed offshore wind sites have been successful for the UK, floating wind has the potential to offer more.
An estimate in the South West Floating Offshore Wind Opportunity Study by Regen suggested the creation of floating wind farms in the Celtic Sea could potentially create 3,000 jobs and provide £682 million in supply chain opportunities for Wales and Cornwall by 2030. Across the UK more broadly, it is estimated to generate 17,000 jobs and £33.6 billion by 2050. Much of this growth will be in new areas which haven’t benefited from fixed bottom sites.
Floating farms can be deployed in a greater range of sites, meaning the potential export market is vast. In January 2022, Crown Estate Scotland granted 17 offshore wind project leases, covering 2,700 square miles of the seabed. Combined, these farms would create 25GW of capacity, with many applications proposing floating offshore wind farms. With the addition of clearing rounds, this now stands at 20 projects and 27.6 GW of capacity.
Building wind farms themselves is one piece of the puzzle, the next is how we collect this energy and integrate it into existing energy grids. The process begins with turbines converting wind energy into electricity. This flows down to the base of each wind turbine, where a transformer takes the electricity and increases the voltage to array voltage levels. This higher voltage is then transmitted through an array cable system to an offshore substation, which acts as a central connection point for the windfarm. Cables laid along the seabed then export electricity to the shore. This diversity of locations provided by floating sites is also useful because they provide greater stability and security when it comes to energy supply, plus more points of entry to the power grid.
By 2050, as required by climate change targets, most of our energy will come from renewables. For the energy system to function effectively, renewables will need to be integrated in ways which enable consumers to use the energy they generate and allow system operators to maintain reliable and resilient energy networks. This is a considerable challenge. At the Carbon Trust, we are supporting this through our Integrator programme which aims to overcome barriers to offshore wind integration and enable rapid deployment of renewables. Our current focus areas include the provision of electricity system services by offshore wind farms and enabling deployment of Power to X solutions, including green hydrogen. Strategic planning for energy transmission will also be important to lower costs and ensure load centres can manage growing electricity input.
Through a combination of technological improvements, increased investment and government support, the growth of the floating offshore wind industry is extremely promising. The UK is expected to be a leader in this industry, but many European countries are looking to follow suit as a way of expanding and diversifying their energy mix. Growth in floating wind promises to bring economic development, jobs and secure energy supply. But more broadly, floating wind success brings with it hope for reducing emissions, reaching environmental commitments and limiting the most extreme impacts of climate change.