Technology testing is moving ahead but uncertainty over support mechanisms is holding back the UK’s plan to take the lead on wave and tidal energy

Who is leading the way in Europe’s drive to develop wave and tidal power sources? The UK has been investing in this developing sector for several years, driven by the large energy resources that are available to be tapped from areas in the North Sea. The region has been an energy powerhouse for the UK for several decades, thanks to its extensive gas and oil reserves, but the end of production is already in sight: in the next few years the majors will begin to abandon worked-out sources, and the remainder will be the preserve of minor companies able to make returns on smaller or less accessible deposits.

As oil and gas production begins to taper off, the UK’s aim is to transfer the extensive offshore expertise to new energy industries, and especially those that will abstract power from the wave and tidal resources in the region. The UK government supported large-scale research facilities in Blyth, Northumberland, where a number of devices have been tested at small scale, and increased its support by investing in the European Marine Energy Centre (EMEC), a test facility sited offshore of Stromness, Orkney, an island off the far northwest of Scotland. Started up with some £15 million ($28 million) of public money, EMEC offered several offshore test berths for wave energy converters, along with connections to onshore laboratory and analysis facilities. The wave test area is now being followed by an area to test tidal energy devices off the nearby island of Eday.

Local initiative

The step from research to deployment of full-scale devices at near-commercial scale is a daunting one for any developer, but in the absence of new initiatives from the UK central government it was a local enterprise agency in the far southwest of the country that took the initiative. The South West Regional Development Agency proposed to install an offshore connection for wave and tidal projects that would enable several arrays of different devices to be operated for a restricted period that would enable them to prove their commercial viability. Although it is far from the northern shores where wave and tidal projects were initially demonstrated, the southwest has some of the country’s most energetic tidal and wave areas, and the project is consistent with an existing commitment in the region – one traditionally ill-served by the existing power network – to develop renewable energy expertise.


Figure 1 – An artist’s impression of the Wave Hub connected to the Pelamis device and the ‘MRC1000’ being developed by ORECon of Plymouth.
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Wavehub, as the project is known, would enable developers to install demonstration arrays at a much lower capital cost, because one of the major costs – connection between the array and the shore-based power offtaker – would be removed. Instead, the projects have only to make a connection to Wavehub. The proposal would also greatly reduce other barriers to deployment, notably the requirement for time-consuming and costly environmental impact reports, and the need to wrestle with the UK’s notoriously obstructive planning process. Instead, Wavehub would carry most of the burden of these two processes.

Work is due to start on Wavehub in 2007 and in August the government pledged to provide a quarter of the necessary £20 million investment – subject to the proposal receiving planning permission. Three companies have signed up to deploy their new technologies at the hub:

  • Ocean Prospect Ltd, a Bristol-based company and subsidiary of the Wind Prospect Group will trial up to ten Pelamis P750 devices developed by Ocean Power Delivery of Edinburgh. The Pelamis is a semi-submerged, articulated structure composed of cylindrical sections linked by hinged joints. The wave-induced motion of these joints is resisted by hydraulic rams, which pump high-pressure oil through hydraulic motors, which drive electrical generators to produce electricity.
  • Ocean Power Technologies, which plans to install a 5 MW project based on its PowerBuoy wave energy converter. PowerBuoy is free floating and loosely moored to the seabed; the buoy’s float moves up and down on the central spar as the waves pass. This mechanical movement drives a hydraulic pump that forces hydraulic fluid through a rotary motor connected to a generator.
  • Fred Olsen Ltd will install a multiple point-absorber system for energy extraction from the waves. A number of floating buoys attached to a light and stable floating platform manufactured in composites converts the wave energy to electricity.

Figure 2 – Ocean Power Delivery’s 750 kW Pelamis device has been chosen for a Portuguese wave energy project
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With an apparently well laid-out route from design to deployment, the UK perhaps should be Europe’s leading wave and tidal country. But in fact, it is in danger of losing its lead and Portugal is likely to be the first to install multi-megawatt wave or tidal projects – and more galling still for the UK, one of its projects will be an array of Pelamis machines, which were tested at Blyth and inaugurated the EMEC site, but may be deployed in earnest off the Iberian peninsula before they can be demonstrated at the UK’s Wavehub.

Jump start

The UK’s biggest stumbling block is the support it provides for new technologies making the jump from demonstration to commercial technologies. In theory, all renewable energy technologies are supported by the “technology blind” Renewables Obligation, which forces electricity suppliers to source a growing proportion of their power from renewable generators or pay a per MWh hour fine. The Obligation was supported by tradable electronic ‘renewables obligation certificates’ generated along with each MWh of renewable electricity. But the Obligation was designed to bring the most developed technologies – in practice, onshore wind – on stream as quickly as possible: there is no incentive to use newer options that will be necessarily more expensive before they have achieved economies of scale and passed the uncertainties of new deployment.

In contrast, wind and wave technologies in Portugal receive a guaranteed “feed in” tariff. It is an arrangement that is popular in several countries because it provides the developer with a fixed and certain return – provided that the project generates successfully. What is more, better performance means a better return.


Figure 3 – The Fred Olsen system extracts energy from the waves using floating buoys attached to a stable platform.
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Ocean Power Delivery shipped three 750kW Pelamis generators to Portugal in mid 2006 and followed it up with an order for a further 28 machines, to be delivered once the performance of the three initial machines has been verified. Richard Yemm, Managing Director of OPD commented: “Portugal has been quicker to prioritize exploitation of its wave energy resource, and to recognize the commercial opportunity that it represents. The Portuguese government has put in place a feeder market that pays a premium price for electricity generated from waves compared to more mature technologies such as wind power. This allows the commercial investment in early stage projects which is crucial to move the technology forward.”

Consistent lobbying for additional support in the UK has been successful. But far from providing a secure and predictable enhanced return, the UK’s attempts to increase support may have simply added more uncertainty. In July, the British government announced in an energy review that it would ‘band’ the Obligation to make sure that it brought forward different technologies: biomass, which has also suffered from the Obligation’s ‘technology blindness’, as well as wave and tidal and potentially other technologies.

More uncertainty

A consultation published in October proposed retaining the Obligation and sought views on how the banding should be allocated and how it should be administered. It also asked for views on doubling the Obligation payments made to wave and tidal projects. The consultation met with a very mixed reaction from developers, who foresaw a protracted period of uncertainty, when neither the likely bands nor the amount of subsidy available could be predicted with any certainty. What is more, the consultation suggested that ‘mature’ renewables technologies could be awarded just a fraction of the RO subsidy in future, to free up cash for the newer technologies. The measure was said to be aimed at projects burning methane from landfill sites, but caused immediate concern to potential wind energy developers.

It was not clear how quickly the new structure would be settled, as although the government planned to complete the consultation in 2007, several of the new measures could not be enacted until 2009 – remaining politically uncertain in the interim.


Figure 4 – Ocean Power Technologies has signed up to use Wave Hub for its PowerBuoy wave energy converter
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If uncertainty at Westminster were not enough, the devolved administration in Scotland, impatient to increase support for what it sees as potentially an important industry for the region, has produced its own proposals. Despite acknowledging that most respondents to a consultation advised ‘no change’, or asked for support in the form of grants, the Scottish Executive proposed providing multiple ROCs for Scottish wave and tidal projects within its own Scottish Renewables Obligation, which operates in parallel to the England and Wales Obligation. That measure is due to be implemented next year, but it is still not known how the multiple Scottish ROCs will be traded in the single ROC market where certificates from the Scottish, Northern Irish and England and Wales markets are intended to be interchangeable. It also appears that the subsidies operated in Scotland and in England and Wales will be incompatible.

Efforts to improve the Obligation, if muddled, do demonstrate that there is widespread political support. And although Portugal will potentially have the first large scale project, Wave Hub should qualify three technologies in its first phase. Nor is Wavehub the only option in the UK: Marine Current Turbines has won support from Northern Ireland and from Wales for ‘Seagen’ an undersea turbine rated at over 1 MW, and also has plans for a 12 MW array off the North Devon coast.

There are more technologies in the pipeline. It remains to be seen whether the UK can refine its subsidies to give these devices the support they need to become commercial ventures.