Floating foundations can be deployed in much deeper water across a wider range of seabed conditions and are therefore a potential vital key for offshore wind to become a truly global industry.
The early deployments of floating technology are providing encouraging results. For example, capacity factors are better than expected for the 30MW Hywind project in Scotland.
But floating costs need to fall much more dramatically in order for it to be considered ready for wider commercial rollout.
Innovation has a vital role to play in reducing costs. In collaboration with InnoEnergy, we recently examined how innovation could reduce the cost of energy from floating offshore wind farms up to 2030.
Some of the cost reductions, such as turbine rating, turbine design and blade improvements, will be just as applicable to fixed foundation projects as floating.
Our work suggests that around two thirds of the total reduction in floating costs to 2030 will be due to these "shared" cost savings.
These innovations would give no competitive advantage to floating technology over fixed, but would be vital in helping it compete with other forms of generation.
Improvements in the design and manufacture of support structures, mooring and floating-specific array cabling can provide cost reductions for floating foundations Advances in installation and O&M will also help nudge costs down, if by relatively small amounts.
As experience grows and costs begin to fall, a virtuous circle will develop: projects get bigger, learning increases, economies of scale kick-in and transmission systems become more effective.
This, in turn, will reduce the perceived risk of using floating foundations which will lower financing costs.
Cost reduction and innovations in floating foundation technology will happen over the coming years.
The key challenge is whether they will be realised and spread quickly enough to attract investment, supply-chain development and further innovation for floating offshore wind farms to develop as a commercially viable option for electricity generation.
Costs and innovation are not the only issues for floating offshore wind to overcome. Policy rather than technology is likely to be the main bottlenecks for the industry.
Most advanced floating offshore wind developers have a diverse portfolio.
They are unsure where the support for floating offshore wind can be found and thus the most likely source of initial projects.
The resultant geographic spread of potential projects makes sense from a portfolio risk-management point of view.
It does, however, mean that these developers have to keep their options open and their supply-chain supported in each of the possible markets.
This spreading of potential makes the possible individual activity for each region much smaller, reducing the likelihood of the required investment in the supply chain and logistics.
In order to have projects that are debt as well as balance-sheet financed, floating offshore wind will need a support mechanism to ensure the costs of capital are not prohibitive to commercial success.
This support mechanism should reflect the risk of the projects, but it should also enable costs to become competitive.
To provide such a support mechanism, a jurisdiction will need to feel confident that it will have some return on its investment, either in guaranteed energy supply, local economic benefit or in export revenue.
Many jurisdictions don’t require much floating offshore wind as a guaranteed energy supply. If other jurisdictions want to keep local content high, then export revenue is not large.
As well as the support for the energy, there is also the infrastructure for the manufacture, installation and maintenance of the hardware.
There are not many ports currently equipped for these activities on a commercial scale. To expand or build a facility that can handle such needs could require billion-dollar investments.
To secure this, the public and private sectors will probably need to share in the investment, which requires a strong business case that is rigorously realistic.
This, in turn, requires confidence in costs, production and the market for any electricity generated.
Idealistic arguments won’t win through, but if we embrace the practicalities, floating offshore wind can develop into a truly commercial, truly global technology.
Kate Freeman is an associate at BVG Associates