The sea is among clean renewable energy sources now being tested in anger since the Kyoto agreement came into force in 2005.
Waves generate more energy than wind but the problem is that it currently costs more to capture it – partly because it is a newer technology.
Machines capable of harnessing wave energy need to be connected to an electricity grid, with the associated costs and technical challenges of both offshore cables and onshore capacity for this high voltage infrastructure.
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Not all coastal areas have sufficient wave power, nor sufficient access to the onshore grid to make them viable. However, just as the cost of wind power has fallen dramatically over the last 20 years so wave energy costs are expected to fall over time. Australia, Hawaii, Portugal, the UK and the US are among countries trying it out.
The UK's South West Regional Development Agency has been working with Halcrow since 2003 to develop a scheme to provide an underwater offshore connection to the National Grid at Hayle near St Ives in Cornwall.
The connection is 16km offshore, in 50m depth of water. It will allow floating arrays of up to 4 different types of wave energy converter devices to be connected at any one time. This is a demonstration project, providing the vital link between prototype development and full commercial viability.
The infrastructure involves the sub-station building at Hayle adjacent to a connection point to the distribution network. From there, a cable will be taken through a duct beneath the sand dunes and then across the sea bed to an eight square kilometre area within which the devices will be moored.
Consent for the scheme was announced by Dti and Defra in September 2007, following an application made in June 2006. The supporting environmental statement is available from the wave hub website (see link provided). The current programme shows the appointment of a contractor in Spring 2008, followed by detailed design, materials pre-order and off-site fabrication. On-site works are scheduled for the summer 2009, with planned commissioning in late 2009.
Benefits
Wave Hub could generate enough electricity for 7,500 homes, directly saving 300,000 tonnes of carbon dioxide over 25 years. This would support South West England's target for generating 15% of the region's power from renewable sources by 2010.
Innovations
This is a groundbreaking renewable energy project in the South West of England that aims to create the UK's first offshore facility for the demonstration and proving of the operation of arrays of wave energy generation devices. As well as the conceptual design, Halcrow selected a suitable location and is assessing the scheme's financial and technical feasibility.