The Next Decade in Wave and Tidal Power

The next 10 years will be crucial for the development of the wave and tidal industry. With the right research and technology, this may be seen in the future as the decade of deployment-the period in which wave and tidal technologies moved into the mainstream alongside other more established renewables. In the meantime, however, there are significant obstacles to be overcome if the technologies being developed are to succeed.

The political pressure to deliver commercially viable wave and tidal energy solutions is such that it generates international news headlines on an almost daily basis. This is astonishing when one considers the fact that less than a handful of technologies have survived prolonged testing and deployment. Although the development of these new technologies has parallels with the onshore wind sector of the 1980s, the political landscape is significantly different. Renewable energy is no longer considered the folly of idealistic hippies-in fact, quite the reverse is now true. It sits at the top of government agendas across the world and takes the form of targets, which politicians are obliged to meet.

The success of onshore and offshore wind in delivering clean energy to grids throughout the world has resulted in significant pressure. This has ensured the scale of the first wave and tidal technologies going into the water is much larger than the early wind technologies, which were allowed to develop more slowly, out of the spotlight. While this large-scale approach might reap faster financial and political rewards once the right approach is found, it also makes the journey fraught with risks.

Although not well coordinated, there are many funding programmes and testing facilities available to aid the development of wave and tidal energy technologies. The question is: how do we take advantage of these while effectively managing the risks involved in moving new technologies from ideas, through to early stage demonstration projects, into large-scale deployment?

While the number of technologies in development is encouraging, the stakes are so high that much of the learning and expertise is veiled in secrecy. In the end, this wide and thin approach is unlikely to yield efficient results. Ultimately, some sort of convergence of technologies and rationalization within the industry will be required to move the focus beyond innovation and toward deployment. The involvement of large industrial players, who have significant financial and technical "muscle," should provide increased levels of confidence to the sector. It will always be easier for organizations like these to attract the interest of utilities and project developers as a result of their ability to provide warranties for their newly developed products.

Probably the most significant challenge for any device developer is the creation of a technology that is able to survive long-term in a hostile marine environment. Although a small number of devices have undergone open-sea testing, none have fully demonstrated the capability to survive in extreme operational conditions. Some very promising tidal turbine devices in the Bay of Fundy, Canada, at the EMEC site in Orkney, Scotland, and in Strangford Lough in Northern Ireland, have suffered failures during installation or testing. Such failures are to be expected during the development phase of new technologies operating in a unique and poorly understood environment, where much of the learning has to be done on the job. What investors in these new technologies must accept, and be prepared for, is a commitment for the long haul.

In the same way there are a range of device concepts, there are also many different approaches as to their deployment and retrieval. The challenges faced should not be underestimated; particularly for tidal energy, where the operating windows and erratic nature of flows around slack water at some of the more promising sites present difficulties that have no parallels in other industries. It's important, however, that wave and tidal technology developers do learn from the experience gained in related industries (e.g. the oil and gas sector), while recognizing that increased cost sensitivity in renewables will always require a balance between extracting maximum benefit from such experience and developing more suitable, cheaper, and bespoke solutions.

One area that demands a special mention is that of seabed cabling for marine renewables as it delivers the biggest single risk as a result of the associated costs, and lack of research and understanding. Wave and tidal energy poses unique challenges such as rocky seabeds, cable laying and protection in near-shore wave zones, and the need for cheap reliable sub-sea connectors and transformer hubs. Though some of these problems are common to offshore wind, the wave and tidal sectors cannot rely on the offshore wind sector to find suitable solutions for all of its needs.

Once devices are successfully deployed, timely and cost-efficient O&M regimes will become crucial in maintaining reliability. Getting it wrong will lead to problems with device availability-a real bugbear for all renewable technologies operating in a hostile climate as it impacts on the supply of energy to the grid. Planning for scheduled and un-scheduled maintenance activities in a way that balances operational costs with lost production is a real challenge. The offshore wind sector is already facing this, and tools have been developed to support the design of cost-effective strategies. These tools should be adapted and utilized for wave and tidal projects as soon as possible.

Once wave and tidal devices start to deliver energy reliably, the focus should then-and only then-shift to cost reduction and performance enhancement. Ultimately, it's the return on investment that brings any new technology into the mainstream and cost reduction can only be achieved when the devices become mature enough to reap the benefits delivered by economies of scale and improved supply chain. Even when this has happened, as it has with onshore wind, the challenge to further improve designs and push down costs continues.

In conclusion, while the risks and challenges in the race for wave and tidal solutions are considerable, they are not insurmountable. Many have been overcome before, either within the wider renewables sector or in a different industry. This knowledge, combined with political support and a modern "yes, we can" approach to renewables, generally creates optimism despite the challenges. The next decade will definitely be challenging, but with sights firmly set on a move into the mainstream, it's also guaranteed to be an exciting journey.


George Gibberd has recently joined GL Garrad Hassan, and has considerable first-hand experience from his involvement in the development and deployment of devices at Marine Current Turbines and Tidal Generation Limited.

GL Garrad Hassan, one of the world's largest dedicated renewable energy consultancy, offers independent technical and engineering services to the onshore and offshore wind, wave, tidal, and solar sectors. Its wave and tidal team experts have worked on more than 60 projects across 18 countries including key R&D projects. They also have experience of projects going in to the water.

GL Garrad Hassan
www.gl-garradhassan.com