Go back to previous list...

Blog: The long-term promise of ocean power

EMEC’s non-executive director, Ian Bryden, features in the Guest Opinion section (page 40-41) of the latest issue of EnergyBiz magazine. The article, which explores the potential as well as the challenges of developing commercial wave and tidal power, is available to read below:


The long-term promise of ocean power

For those of us who were involved in wave power research in the 1970s and 1980s, it has been a very long time to see dreams of energy from the seas becoming a reality. Even the new generation of entrepreneurs and researchers must occasionally feel that the dream remains tantalisingly over the horizon. However, very real progress has been made in the last 10 years. We have seen prototype wave and tidal current energy devices tested at full scale and the findings from these tests being used to revise system designs. We now have a much better appreciation of the challenges that must be overcome before costs can be reduced to compare with onshore wind.

The prizes for those working to develop commercial marine energy are considerable. The theoretical offshore wave resource in Europe and the rest of the world is massive. In principle, for example, the average rate of wave energy incidence on the west-facing coastal contours of the United Kingdom and Ireland exceeds 50 gigawatts. The UK, Irish and Scottish governments are highly aware of this, which explains their funding for research, development and implementation of wave energy. The achievable technical resource and the commercially practical resource will, of course, be significantly less than this and will be dependent upon the identification of technology and constraints upon development.

We know that full-scale systems are only now demonstrating their capability at sea. Machines have to face massive forces in winter storms, which requires design for resilience. They must also maximize generation in modest conditions, which demands design for system sensitivity. The difficulties of achieving these apparently contradictory aims have occupied the minds and bank balances of device developers for decades. Only now, however, is full-scale experience becoming available from work at the European Marine Energy Center in Orkney in the United Kingdom and other test sites, as they become available. Providing that development funding remains available, it is likely that the next stage of device demonstration will be small arrays of machines redesigned as a result of experience. Once credible commercial machines have been demonstrated as reliable, then the usual “laws” applying to the economics of early-stage commercial development will apply and costs will come down as installed capacity increases — but how quickly and how far are interesting questions.

The tidal current resource is always going to be a niche opportunity in comparison to wave and wind. The resource itself is much smaller at a world level and is less widely distributed. Those areas where the resource is credible, such as the Pentland Firth in Scotland, the Bay of Fundy in Canada and interisland traits in Southeast Asia, do possess very significant energy densities. Estimates of the resource in the Pentland Firth, for example, vary widely but there is increasing consensus around 2 gigawatts as an achievable average power output from suitably optimised exploitation scenarios. The predictability of the output from such a development would increase its attractiveness to energy utilities.

In many ways, the experience of commercial tidal system development has overtaken that for wave energy. This is probably because of less challenging ratios between loading under operational and peak conditions. Also, it is obvious to even the most casual observer of the sector that many tidal machines look rather similar. This is a result of convergence as designers respond to the challenges of the resource and the environment. There are more opportunities, therefore, for standardization in support infrastructure, including installation and maintenance technology. Developer experience is likely to facilitate the move to pre-commercial arrays in shorter timescales than for wave and tidal current technology and may already be moving into the early stages of cost reduction as deployments increase.

In the decade ahead, providing development funds remain available, we will soon see tidal arrays being deployed, with the smart money being on the Inner Sound of the Pentland Firth as part of what is known as the MeyGen project. True commercial development will depend upon prospective public and private investors being convinced that the technology has really moved into serious cost reductions associated with increased deployment. There is no reason why this cannot happen but, of course, it is dependent upon the skill of engineers and the patience of investors.

Progress with wave development, which offers a vastly greater ultimate prize at an international level, will depend upon continual progress in solving the reliability and survivability of technology. There is no reason why this cannot be achieved, however, the timescales will be longer than for tidal. In many ways success in an embryonic tidal sector will be crucial to the development of wave energy. If tidal devices can be shown to offer commercial opportunities, then this will go some way toward alleviating concerns about wave technology. The greater potential for wave energy might then overcome temptations to stick with the more immediately available tidal technology.

Ian G Bryden
Non-executive Director, EMEC


Article republished with permission from CyberTech, Inc. EnergyBiz® enables senior level power executives to connect with the strategic information, knowledge and industry colleagues daily. For more information or to get your FREE subscription, visit http://www.energybiz.com.

-

EMEC CLIENTS

Alstom

Alstom

hammerfest

hammerfest

Aquamarine

Aquamarine Power

atlantis

Atlantis Resources Corporation

Nautricity

Nautricity

Naval Group

Naval Group

openhydro

Open Hydro

Home_Orbital-Marine-logo

Orbital Marine

pelamis

pleamis

scottish_power

ScottishPower Renewables

seatricity

Seatricity

Sustainable Marine Energy

Sustainable Marine Energy

voith

Voith Hydro

Wello

Wello Oy

Supported by: