New research to support the huge potential of tidal power
New research from a global group of scientists and engineers, including from the University of Southampton, has been published in a special issue journal of the Royal Society. The work is in support of tidal power, which has the potential to provide more than 20 per cent of the UK’s electricity demand.
While the predictable nature of tides makes them an ideal renewable energy source, more so than wind, the ability to effectively harness energy from the tides has proved elusive.
In order to develop effective tidal current technology, a special issue of the Philosophical Transactions of the Royal Society A* describes the status of leading research and projects in the field to rapidly advance tidal energy technology.
AbuBakr Bahaj, Professor of Sustainable Energy at the University of Southampton and editor and contributor to the special issue, says: "The energy present in marine currents can be converted using technol ogies not too dissimilar to those used in wind energy. While technologies harnessing energy from the tides and currents have been discussed for many years, it is evident from recent deployment of single devices at megawatt scale that real progress has been achieved in a very short period of time.
"In essence, experience with single machines at such a power capacity, will make progress to deployment of multiple machines to convert the marine energy resource much faster than that achieved at the start of the wind energy industry."
Although the potential for marine energy conversion clearly exists, the technology is presently still in a commercial prototype phase and only a handful of devices have so far been tested at full scale in the ocean. Unlike wind energy, there are currently various designs being promoted, with no single device design emerging as a winner so far.
Engineers try to tap tides in two ways: one involves building barrages across tidal estuaries that use tidal differences in sea surface elevation, so that the flowing waters turn turbines in a similar fashion as hydropower installations.
The other method involves placing turbines underwater in areas of the sea where fast flowing tidal streams, such as those found in coastal waters around the Channel Islands and Scotland. The technology could be similar to the three bladed turbines used in wind energy with the flowing waters replacing air. Developing power from offshore tidal streams is fraught with difficulty, but according to the authors of the latest research, 2013 could see a big breakthrough in tidal stream power. There are several companies planning to deploy arrays of tidal turbines in UK waters. For example MeyGen ( www.meygen.com ) is planning to deploy tidal stream technology in Scotland's Pentland Firth that will initially generate up to 40MW of electricity, enough to power about 38,000 homes.
"This is a crucial milestone for technology development and deployment. Currently, it appears this will be the first deployment of an array of tidal stream turbines," says Professor Bahaj. "Such deployment will give a boost to the industry as it will also provide the needed data of operation in one of the most energetic areas of the sea. Overall, tidal power will also give us another component in the energy mix that's more energetic and reliable than wind."
In the journal, researchers say they are "extremely optimistic" that tidal stream technology can be realised relatively soon. However, while the articles paint a positive future for tidal power, a critical element is the availability of funds to undertake such deployment.
In the past month, the EU has announced funding in the region of £30m for two UK tidal projects. Investors in tidal technology are currently rewarded with a payment of five Renewable Obligation Certificates (ROCs) which are market variable. Each ROC is approximately £40 per megawatt hour of energy generated from such a resource, but this scheme will be reviewed in 2017.
According to Professor Bahaj, this could have serious implications for the emerging industry: "The rollout of the technology in its current state will depend on the subsidies. At this stage, it wouldn't stack up financially, until wide experience gained from large-scale deployment is achieved."
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Notes for editors
1. The research presented in the special issue of the journal Philosophical Transactions of the Royal Society A* comprises an elite selection of articles within the marine current energy conversion area. It covers the key focal points of the international research, such as turbine design, performance and optimization, tidal resource assessment, array design and wake interactions, while the methodology of the work encompasses numerical modelling, experimental studies as well as field measurements.
The idea for it was conceived during the 9th European Wave and Tidal Energy Conference ( EWTEC-2011 ) held in Southampton, UK, in September 2011, the world's largest and most renowned academic conference in this field. The high quality of the research articles submitted for this conference prompted the wish to dedicate an entire Theme Issue to the tidal energy topic, detailing the focus of the current research. The best papers were selected by the conference's technical and management programme committees and further developed by the authors and reviewed to fit within the framework of this Theme Issue.
2. The Sustainable Research Group (SERG) within the Faculty of Engineering and the Environment at the University of Southampton is one of the leading university groups in renewable energy and energy in buildings ( www.energy.soton.ac.uk ). The aims of the Group are to promote and execute fundamental and applied research and pre-industrial development in the areas of energy resources, technologies, energy efficiency and the impact of climate change on the built environment. In marine energy the group has published over 100 articles and has developed new knowledge, which contributes to our understanding of tidal energy conversion and fundamental understanding of specific wave energy devices. SERG were the host for the EWTEC2011 held in Southampton 5 - 8 Sep 2011.
3. The University of Southampton is a leading UK teaching and research institution with a global reputation for leading-edge research and scholarship across a wide range of subjects in engineering, science, social sciences, health and humanities.
With over 23,000 students, around 5000 staff, and an annual turnover well in excess of £435 million, the University of Southampton is acknowledged as one of the country's top institutions for engineering, computer science and medicine. We combine academic excellence with an innovative and entrepreneurial approach to research, supporting a culture that engages and challenges students and staff in their pursuit of learning.
The University is also home to a number of world-leading research centres including the Institute of Sound and Vibration Research, the Optoelectronics Research Centre, the Institute for Life Sciences, the Web Science Trust and Doctoral training Centre, the Centre for the Developmental Origins of Health and Disease, the Southampton Statistical Sciences Research Institute and is a partner of the National Oceanography Centre at the Southampton waterfront campus.
For further information contact:
Glenn Harris, Media Relations, University of Southampton, Tel: 023 8059 3212, email: G.Harris@soton.ac.uk
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