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Rising tide of marine energy to lift the UK

21/01/2009

  • Energy efficiency,
  • Water
  • United Kingdom
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The United Kingdom is at the forefront of marine energy research and development, and many believe this growing sector could in the future meet a fifth of all British energy demands.

The development of marine energy is progressing at a fast pace in the UK. Through the combined efforts of both public and private organisations, this renewable energy sector could provide an answer to the country's future power needs. In an effort to capitalise on its strength in this area, the UK Government has been proactive in introducing measures to develop this sector.

The Government-created European Marine Energy Centre (EMEC) is an institution that is driving the marine energy industry forward. In collaboration with private technology companies and government bodies, EMEC is striving to make marine energy a significant contributor to the national grid. The UK having some of the best wave resources in the world is estimated to possess the capacity to generate approximately 87 TWh of wave power annually, equivalent to 20% to 25% of current UK demand.

Based in the Orkney Islands, Scotland, EMEC is an internationally renowned centre for the development of tidal and wave energy. The institution was founded to aid the evolution of marine energy devices, and to guide them from the prototype to the commercial stage. Over the last five years, EMEC has established itself at the forefront of marine-based renewable technology development.

The centre, situated in and around Stromness, is the first of its kind in the world. It offers developers a unique opportunity to test full-sized prototypes of their devices in severe wave and tidal conditions. Many of the recent successful developments in this sector have been enabled by the facilities on offer at EMEC.

A case in point is the pioneering work of Scottish-based manufacturer Pelamis Wave Power. Pelamis has been developing its wave-energy converters at EMEC since 2004. By working with EMEC, Pelamis was able to install these converters at the world's first commercial wave farm in Aguçadoure, Portugal in September 2008.

Built in 2003, EMEC consists of both wave and tidal test sites. Testing takes place in a wide range of sea and weather conditions, and the institution provides around-the-clock monitoring to provide the best analysis of the performance of prototype devices. EMEC was the scene for a world first when Pelamis generated electricity for the national grid from the centre's wave test site. This was made possible due to the fact that EMEC's wave and tidal sites are connected to the national grid via seabed cables.

Part of broader plan

EMEC was created by the UK government as part of its broader plan to have renewable energy contribute 20% of national power by 2020 in line with EU targets. The Government, together with public-sector organisations such as the Carbon Trust, has invested €19 million in the creation of EMEC and its two marine laboratories.

The achievements of EMEC have been widely honoured in recent years, with the centre receiving accolades in both the Scottish Renewable Green Energy Awards and the Northern Star Business Awards. The success of the centre has brought marine energy to the attention of many in Scotland and the rest of Britain. As a result, the Scottish Government is now awarding €15 million in the shape of the Saltire Prize to the creators of the most innovative marine renewable-energy technology deployed in Scotland.

As EMEC has highlighted the viability of marine energy as a real power source, politicians have now begun to show their support for the centre.

“Scotland has a huge renewable energy potential - enough to meet its demand for power almost 10 times over,” says John Swinney, Scottish Cabinet Secretary for Finance and Sustainable Growth. “Our coastal geography and tidal channels mean we can be a world leader in new wave and tidal energy technologies. The pioneering work of the European Marine Energy Centre is a perfect example of how we can successfully achieve this. The Scottish Government is determined to support these new technologies wherever possible - both to help tackle climate change and to increase sustainable economic growth.”

The Scottish Government has also allocated funding for Scotland's first wave farm. It will have a installed capacity of 3 MW provided by four Pelamis machines, and will be located at EMEC. The funding of just over €5 million is part of a €16 million funding package for marine power in Scotland.

Wave and tidal test sites

EMEC has both wave and a tidal test sites. The centre's wave site is situated at Billia Croo, and consists of four test berths that are located in an area 2 km offshore, with a water depth of 50 m. The wide variety of developing wave energy converters tested at this site can be divided into six distinct types: attenuators; point absorbers; oscillating-wave surge converters; oscillating water columns; overtopping devices; and submerged pressure-differential devices.

The EMEC tidal centre, located west of Eday, consists of five test berths that are in an area with marine currents of 7.8 knots. This site connects the berths to a substation by way of sea-bed cables; it also provides conditioning and converting equipment to enable the creation of grid-compliant electricity. As with the wave site, a range of technologies are regularly tested here, such as: horizontal-axis turbines; vertical-axis turbines; oscillating hydrofoils; and Venturi-effect devices.

More information:

photo courtesy of Pelamis Co.

Marine Energy Accelerator

The UK Government-funded Carbon Trust, one of the original funding partners of EMEC, continues to support the operational costs of the centre. Alongside this, the Carbon Trust is currently overseeing a marine energy initiative known as the `Marine Energy Accelerator’. This initiative builds on its `Marine Energy Challenge’, which suggested that marine energy could meet 20% of Britain's future energy needs. The project aims to reduce costs connected to this technology by supporting: the development of new Marine Energy Device concepts; research and development into specific component technologies; and the development of low-cost installations. The initiative will involve a range of important players in the sector, and has been allocated €4.4million for project support.

More information:

www.carbontrust.co.uk/technology/technologyaccelerator/mea.htm

Pelamis Wave Power

Edinburgh-based marine energy manufacturer Pelamis Wave Power was established in 1998. Its engineers have discovered practical means to harness wave power, the flow of currents and the motion of tides. Through rigorous testing at EMEC, Pelamis developed and perfected its wave-energy converter linear absorbers, which are semi-submerged articulated structures composed of cylindrical sections linked by hinged joints. When waves change the sections positions relative to one another, the joints push hydraulic rams which pump high-pressure oil through turbines inside the cylinders. Pelamis installed three wave converters at the world's first wave farm in Aguçadoure, Portugal in September 2008. These three wave converters are just the initially stage of the development, which will grow to 25 converters with a 25-MW capacity.

More information:

www.pelamiswave.com

Marine energy could meet 10% of global demand

According to market research firm Frost & Sullivan, wave energy sources are not only available in plenty, but are also consistent, predictable and have the highest energy density among all renewable energy sources. The best resource is found between 40 and 60 degrees of latitude where the available resource is 30 to 70 kW/m, with peaks of 100 kW/m. The potential worldwide wave energy contribution to the electricity market is estimated to be of the order of 2,000 TWh/year - about 10% of global electricity consumption. According to the consultants, government support that helps share the risk of emerging technologies, for instance through financial investment into start-up firms or support for research & development, is needed to accelerate the uptake of marine energy sector technologies.