Commercial power from the oceans remains some years away, but some of the world’s biggest companies are backing the sector, writes Mike Scott
The wave and tidal power sector remains in the very early stages of its development, with no more than 10 megawatts of capacity in the water.
To an outsider it may seem that little progress is being made in marine energy, but there have been significant developments over the past year to suggest the sector’s prospects are brighter than ever.
The potential has never been in doubt and was recently confirmed by the Crown Estate, the body that leases the seabed around the UK’s coastline, which said tidal and wave power could, in theory, provide a significant proportion of the UK’s total generating capacity of 80 gigawatts (GW).
The Carbon Trust estimates that by 2050, 11 per cent of the UK’s electricity supply, or 13GW, could come from the waters around the UK.
“While the science of wave and tidal resource assessment is still emerging, it is clear that wave and tidal energy could contribute substantially to the UK’s electricity needs,” says Rob Hastings, director of the Crown Estate energy and infrastructure portfolio.
“The UK has the largest wave and tidal resource in Europe, which could produce 20 per cent of current UK electricity demand and cut carbon emissions,” according to Energy and Climate Change Secretary Ed Davey on a recent visit to EMEC, the European Marine Energy Centre in the Orkney Isles, the world’s only fully accredited marine energy test centre.
The arrival of large companies with deep pockets and significant experience of project development has helped to generate interest from utilities
GlobalData says that, even at this early stage, the UK is considered the most attractive destination to develop marine projects in Europe, while Stephen Wyatt, head of technology acceleration at the Carbon Trust, estimates wave and tidal energy could boost the UK economy by £3 billion a year, create 26,000 jobs and lead to £8 billion of exports.
The sector is entering a third phase of development, says Dr Wyatt. The first phase was academic testing and modelling in university labs, the second phase was spinning out the technology to develop it commercially and the third phase “is where the big guns come in”.
The guns couldn’t be bigger. Investors into the sector include Siemens, which has bought Marine Current Turbines, while Alstom has acquired Tidal Generation and French marine engineering group DCNS has taken a stake in Ireland’s OpenHydro. The backers of Aquamarine Power include ABB and SSE. Meanwhile Swedish utility Vattenfall, Babcock International and Spain’s Abengoa have started a company to provide engineering services for wave and tidal power projects.
The presence of these giant companies is crucial for the marine energy sector, says David Krohn, wave and tidal energy development manager at RenewableUK. “The big players bring a massive increase in credibility. These guys have the engineering capabilities to take on large-scale and highly sophisticated projects. You can also rely on these companies to provide guarantees and stand behind their products.”
Utilities are not going to sign up for 100-device arrays made by a university spin-out because any such company would not have the capacity to deal with any problems, says Dr Wyatt. “The Siemens and Alstoms of the world do have this capacity. That is their job. Their involvement is a real sign of the sector’s maturity.”
The arrival of large companies with deep pockets and significant experience of project development has helped to generate interest from utilities, too, with Eon, SSE and Scottish Power among the power generators involved in the sector.
There is still some way to go before marine energy becomes a significant part of the energy mix, however. Marine energy project developers remain at the stage of installing single devices in the water, many of them at EMEC, and there is currently little more than 10 megawatts of installed capacity, according to Dr Wyatt.
Much of the UK’s tidal resource is concentrated in the Pentland Firth between the Scottish mainland and Orkney, but other sites include the Humber, Mersey and Severn estuaries. In the Humber, for example, Neptune Renewable Energy has deployed a device designed for sheltered estuarine conditions and it is planning for a commercial array of devices in the Humber within the next two years.
During the next five to ten years, the industry will be focusing on stepping up from showing that single devices work to installing multiple-device arrays and proving they are able to deliver reliable supplies of energy at lower cost. “The first devices went in almost at any cost,” says Dr Wyatt. “These were research and development projects that could cost up to £30 million for one turbine. We cannot do that again. We have to figure out how to do it cost efficiently. This is where the big companies come in; they have the ability to drive down costs.”
Tidal and wave power have been developing at roughly the same rate up to now, but certain differences have started to become apparent. In tidal stream, there is a high level of technology convergence, with the industry starting to settle on horizontal axis turbines, says RenewableUK’s Mr Krohn. While in wave a number of different technologies remain in play, not least because the range of conditions in which power can be generated varies from deep, open water to near-shore and shoreline, while devices can be floating, fixed or embedded.
This means that, while the ultimate prize in terms of generating capacity both around the UK and globally is greater in wave energy, tidal stream is likely to develop more quickly in the short term. “Many of the equipment manufacturers are more used to rotating plant. It is a more natural fit with their skillset and they have a greater understanding of how to design out the cost,” says Dr Wyatt. “In wave, it’s still tricky to work out which is the best technology. They are all quite different and they work in different conditions.”
However, wave will benefit from many developments in the tidal sector, he adds. “The business of making technology robust in the marine environment is similar in both areas. We may see the OEMs [original equipment manufacturers] cut their teeth on tidal and then move into wave.”