21 Nov 2007
UK Wave and Tidal Industry: firmly anchored or drifting out to sea?
So often today the UK media is driven by a new headline about climate change, its effects and how the government and public can combat rising carbon emissions. Climate change is now a fact and sits at the top of many government agendas throughout the world. The UK is no different but critically, the government may be overlooking the answer to the question of how to reduce the country’s carbon emissions.
The UK has committed to reaching the European Union’s (EU) 2020 targets which aim for a 20% reduction in emissions throughout Europe. Recent reports have indicated that the government is focusing on large scale solutions such as nuclear power, which will take extensive amounts of time and money to implement. Many environmental experts believe the solution for the UK lies in applying several renewable technologies which when combined together could achieve the EU goals and beyond. New renewable technologies are being developed all the time and many experts believe there is a definite way forward.
One of the technologies rapidly emerging as a solution is marine renewable energy or wave and tidal power which could indefinitely supply up to 15 to 20 percent of the energy needed in the UK. The UK is home to one of the best wave and tidal energy resources in Europe but so far has only marginally tapped into its potential.
Harnessing wave power
Waves are created by the wind on the surface of the water and they carry energy; the bigger the wave the more energy it has and this can be harnessed to create power. Although the industry is still in its infancy, recently there has been much wider publicity and promotion of this valuable renewable energy source. There are currently four main methods of harnessing wave power:
• Large buoys float on the surface of the sea and are forced to move by the waves, the motion of the buoys created by the waves produces power.
• Terminators again float on the surface of the sea but it is the motion between the floats caused by the wave which creates the power.
• Overtopping is the method by which a floating pool sits in the water. As the waves hit one side the water is forced into the pool and the water is released back into the sea via a turbine which produces power.
• Oscillating water columns provide energy through the movement of air through a turbine which is created by the movement of the water in the tube.
The coastline of Scotland is particularly good for this technology and is already producing renewable energy from wave power.
Harnessing tidal power
Tidal power is a predictable source of energy and can be accurately forecast at any given time. The twice daily tides in the UK mean that there are areas where fast moving currents occur (tidal streams) as water flows between different tidal heights. The best places to harness the energy created by the tidal streams are around headlands or in between islands.
The UK benefits greatly from good tidal streams and high tidal ranges both of which can be successfully tapped to produce power. Four main technologies exist for harnessing tidal power:
• Cross flow turbines rotate as water flows through them producing power and are best situated in strong tidal streams.
• Hydrofoils are placed in the water and move up and down in the tidal stream the movement creates power.
• Turbines are fixed to the sea bed and rotate as the tide moves ebbs and flows, the movement of the turbines creates power.
• A barrage can be built within the tidal stream area and use the ebb tide to produce power but they are very costly and can have significant impact on the environment.
Recently the government commissioned a feasibility study for building a barrage across the River Severn which would stretch ten miles across the estuary. It would be the largest tidal impoundment facility in the world and could produce up to 5% of the UK’s electricity. However for many years there has been debate about the barrage and with extensive environmental and sustainable concerns no decisions are likely in the near future. Despite the renewable benefits of the barrage, the costs are significant with estimates of over 15 billion and time to implementation could take over 10 years.
How can wave and tidal power help?
Future Energy Solutions has indicated that the worldwide potential output of wave power could produce enough energy to satisfy global electricity demands. However it is finding suitable sites which will produce significant volumes of power which may reduce the practicalities of achieving this.
It has been estimated that there are a potentially 42 tidal sites around the UK which could produce energy amounting 34% of the UK’s electricity. Currently any proposals for renewable technology installations have to go through rigorous feasibility and environmental impact assessments which then need to be approved by the government through a consultation process. The technology for wave and tidal power is also still in its infancy and the true extent of its potential has yet to be accurately determined. Despite this, there is growing support for these technologies as a cost efficient and low impact method of producing renewable energy. The UK is ideally positioned to create a new industry in this arena and potentially become a leading world supplier.
With so much focus in the press on climate change and renewable energy the government had agreed to the EU targets of an overall reduction in carbon emissions of 20% by 2020. It has been recently highlighted that the government is concerned that these targets might not be achievable by the UK and considerations regarding nuclear power and more recently the Severn Barrage are still no further forward. Many environmental groups believe the answer lies in a combined approach to renewable energy in order to achieve the targets. Wave and tidal power is regarded as very much part of this process.
Although nuclear power stations will provide significant amounts of energy and it is thought the Severn Barrage could provide up to 5% of the UK’s electricity needs, the planning and implementation of these solutions could take more than a decade and cost billions of pounds. In contrast wave and tidal power farms could be established within three years at a fraction of the cost, therefore helping to reduce emissions while the larger projects are ongoing. Groups such as Friends of the Earth and Greenpeace are now lobbying the government to consider more of the alternatives in order to begin to have an effect on reducing UK carbon emissions.
Recently proposals were submitted by E.ON UK and Lunar Energy, to the government for a tidal power station to be situated off the coast of Wales which could serve over 5000 homes by 2010. An environmental impact assessment has yet to be carried out but if the station goes ahead it will be one of the biggest in the world.
In the near future it could be possible to establish underwater sites at various locations throughout the UK which would provide a predictable and consistent source of renewable energy around the clock.
In order for the government to meet its targets a practical and bold renewable energy strategy needs to be implemented. Without both short and long term renewable solutions the UK is likely to be left behind in what could be the next biggest industry in the global market. In order to remain a leader in the fight against climate change, the UK has to begin to implement solutions which have an immediate and proactive effect on carbon emissions.
Wave and tidal power is without doubt a strong contender for supplying the UK with a significant energy resource. The lower costs of implementation and shorter timeframes can only serve to make the case for establishing multiple installations around the UK and bring the government a step closer to achieving the EU targets.
With both the skills and industrial capabilities available the UK is well placed to establish an industry and economic growth in the renewables sector. Climate change is here to stay and in relying more on renewable technology to combat its effects, the UK could eventually become independent from imported fossil fuels to support its energy needs.
Wave and tidal power is just one way the UK can begin to reduce carbon emissions effectively. There are now so many avenues both for the individual and the UK as a whole to contribute to reducing carbon emissions, from ground source heating and energy saving bulbs to solar panel heating and biomass and biofuels. What is crucial to successfully reducing carbon emissions is a commitment to invest in the technology and bring forward the implementation of solutions which form one of many parts to the whole plan.
Notes for Editors:
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