Floating offshore wind is no longer confined to the laboratory: it’s a viable technology ready to be rolled out on an industrial scale, according to a “vision statement” from WindEurope released on the occasion of the Offshore Wind Energy 2017 event in London in June.
Not only has the technology for floating offshore wind reached maturity, costs are also predicted to plummet in the coming years, says WindEurope (formerly EWEA). One of the key advantages of floating offshore wind is that turbines are located further away from shores in areas with higher average wind speeds without depth constraints.
Turbines can be significantly larger on floating installations and construction, installation, operation and maintenance costs could be lower than on fixed sites.
Ivan Pineda, WindEurope director for public affairs commented: “Floating offshore wind is no longer an R&D exercise. The technology has developed rapidly in recent years and it is now ready to be fully commercialised in utility scale projects. Adding this option to the market means more offshore wind in total and it’s this extra capacity that we will need to meet the 2030 goals.”
Floating offshore wind offers a vast potential for growth, says WindEurope. 80% of all the offshore wind resource is located in waters 60 m and deeper in European seas, where traditional bottom-fixed offshore is less attractive. At 4000 GW, European floating capacity potential represents significantly more than the resource potential of the US and Japan combined, WindEurope estimates.
“Tapping into this inexhaustible resource will be key to expanding the overall capacity of offshore wind and will support the EU in reaching the target of 27% of energy from renewables by 2030”, says WindEurope.
As highlighted in another new WindEurope report, Unleashing Europe’s offshore wind potential, offshore as a whole could in theory generate between 2600 TWh and 6000 TWh per year at a “competitive cost” – €65/MWh or below – representing 80%-180% of the EU’s total electricity demand.
Summary of the WindEurope vision statement:
There are currently four substructure designs for floating offshore wind: barge, semi-submersible, spar buoy and tension leg platform. The first three are loosely moored to the seabed, allowing for easier installation, while the tension leg platform is more firmly connected to the seabed. This allows for a more stable structure.
The technology readiness level (TRL) related to semi-submersible and spar buoy substructures has entered a phase (>8) in which the technology is deemed appropriate for launch and operations (see Figure 1). The barge and the tension leg platform (TLP) concepts are projected to reach this stage in the coming years.
FOW (floating offshore wind) allows power generators to tap into areas with much higher wind speeds. At greater distances from the shore, the wind blows more strongly and its flow is more consistent. By using FOW, developers can make use of larger areas avoiding wake effects from nearby wind turbines or other wind farms.
Also, larger wind turbines that will be developed in the near future, for example 12-15 MW, can be installed on FOW substructures. The combination of larger wind turbines, producing power over longer lifetimes, and larger projects, could make FOW economics as attractive as BFOW (bottom-fixed offshore wind).
FOW projects can also have a smaller impact on environmental surroundings when used in far-from-shore projects, as noise and visual pollution will be less of a concern in deep-water, remote offshore marine areas.
Europe has an exceptionally large potential for FOW, as shown in the table below:
FOW will also allow countries like Norway, Portugal or Spain, where the potential for BFOW is very limited, to enter the offshore wind industry.
But despite its immense potential, there has not been a single utility-scale FOW project commissioned yet. Technology is no longer a barrier, but there are other challenges to overcome if FOW is to move quickly into the mainstream of power supply.
Two major and interlinked challenges are access to investment and political commitment.
As the industry is still in its early stages, it needs investor commitment to facilitate the transition into the mainstream. Projects require significant investments and their bankability could be eased through financial instruments that address long-term uncertainty, such as guarantees and other hedging instruments. Governments could play a role by bridging public and private financing to offer such financial instruments.
FOW also needs sustained investments in research and innovation to accelerate cost reduction, particularly in those technologies very close to commercialisation.
Generating optimal solutions requires investments in technology. This is likely to be carried out mainly by industry. However, if there are no incentives (ie, demand) to develop new technologies, companies are less likely to shift R&D efforts away from existing products. Therefore, in order to facilitate this industrial development, governments around Europe should acknowledge the potential of FOW and aim to integrate the technology into their planning of energy infrastructure.
Broad political commitment would add to the financial security of projects, and industry and investors will thus be more likely to increase development commitments and investments.
While FOW is a new sub-industry in wind power generation, it has strong technological ties to BFOW. FOW will be able to benefit from existing offshore wind technologies, whilst adding value in the further development of the overall industry.
FOW complements the BFOW industry by adding more capacity to the supply chain and by introducing new technology and developers. This will improve not only the existing conditions of the industry, but will also speed up technological development, as more overlapping research will be carried out on turbines, cabling, electrical inter-connections and O&M.
FOW will also allow the industry to explore new regions, thereby widening the market and adding to the investment and volume needed to meet cost-reduction goals. This will additionally enhance economic conditions in certain regions and generate trickle-down effects into supporting sectors.
In the same way that BFOW followed on from progress in onshore wind and allowed an increase in wind power capacity in Europe, FOW has the potential to further increase offshore wind power capacity. Indeed, deeper offshore areas represents 60-80% of the offshore wind potential in Europe.
FOW can also be an alternative to BFOW, as it can be more easily installed in areas with poor seabed conditions and would also enable the potential recycling of currently abandoned sites (initially studied for bottom-fixed projects).
This is exemplified by a project in the UK where The Crown Estate has leased out 47 GW of seabed. WindEurope has observed that around 12 GW of that space has been cancelled. Part of this area could potentially form a floating pipeline.
European leaders have committed to reaching an EU-wide target of at least 27% share of energy from renewables by 2030. To reach this target and further enhance the energy transition, it is vital that policymakers acknowledge the potential of various renewables, including FOW.
FOW can be an excellent component of the energy mix. It offers a continuous and stable supply of electricity given the characteristics of the wind resource available at distances further from the shore where water depths are higher. FOW could allow more countries to benefit from offshore wind to meet their renewable energy ambitions, especially those where the conditions to develop BFOW are less attractive.
Some pre-commercial projects have already been initiated around the world. In Europe, Portugal and France have introduced projects that are likely to go online as early as 2018. In Scotland the first project will be commissioned in 2017.
The industry is ready to gear up for commercialisation. Several projects are already backed by key players in the finance and insurance services in Europe.
In recent years, we have already witnessed significant cost reductions in both the onshore and BFOW sectors. FOW is anticipated to follow a similar downward trajectory. FOW costs are expected to decrease by 38% by around 2050 while the IEA floating offshore wind expert group suggests that there can be up to a 50% cost reduction by 2050. See Figure 2.
There are several other factors which may also lead to further cost reductions. One of the key advantages of FOW is that turbines will be located in areas with much higher average wind speeds, giving turbines the ability to harness the best possible wind resources without depth constraints. The capacity factor can thus be improved, leading to lower levelised cost of energy.
The significant increase in turbine sizes is another factor. Larger turbines are a good fit for FOW as they can withstand high wind speeds and generate higher output per turbine.
Introducing floating offshore turbines will also reduce both costs and risks currently related to traditional BFOW construction, installation, operation and decommissioning. As turbines are located on floating structures, there will be fewer operations taking place below sea level, and installations and continuous maintenance of foundations will thus be less risky to conduct. In addition, most of the decommissioning activities will be carried out onshore, reducing costs, risks and environmental impacts.
Further, FOW will be able to benefit from economies of scale in the existing and well-developed BFOW sector. Several elements of the turbine design, structures and construction will overlap with BFOW. Thus, both sectors can benefit from further development.
The FOW industry in Europe believes that a stronger commitment is needed to maintain Europe’s global competitive position. Both Japan and the US have technology and deployment pathways for FOW. Europe therefore needs to see a more defined European pipeline of projects in order to ensure continuous leadership in the offshore sector.
Within Europe, it is more likely that existing offshore wind markets will adopt FOW as opposed to new markets coming straight in with floating turbines. The industry thus expects that markets such as Portugal, Spain, France, Ireland and Scotland are more likely to progress earlier with the development of FOW.
Not only is the continuous development of FOW important to maintaining Europe’s global leadership in the offshore wind industry, the further expansion of an already strong industry will also further enhance economic conditions in countries, regions and communities embracing FOW.
With a broad and strong European commitment towards FOW, the sector will be able to develop at a faster pace. Such commitment will lead to increased stimulation of R&D to develop world-leading solutions that can be exported to global markets.