a brief Synopsis
Athens, Greece 01/10/1994
DAEDALUS Informatics
10/9/2001*double click on empty space anywhere on page, to access pagetop
1. Introduction1.2. Marine Wave Energy - A design challenge
The reasons that make wave energy a renewable resource that can simply not be neglected, are quite apparent in either national or international domains. But for many countries it is the waves that provide the best hope of developing a major energy source with no environmental objections to overcome. Evidently, the waves contain the amount of energy the world needs. Rough estimates, put the figure for wave power at 1 terawatt (TW), the equivalent of the world's electricity production, from the waves arriving at the coast, and at 10 TW for the power in the open sea. That is comparable with the world's power consumption. Early market estimations indicated a potential of
$32 billion in the United Kingdom -a leading country in wave energy research- whilst an $800 billion equivalent was estimated worldwide. Wave power has the potential to generate 2,000 TWh of power a year around the world, and Britain wants to capture 2.5% of that amount. The government recently announced a wave power program to monitor development of projects funded under a renewables program, and will support R+D and demonstration projects. The coast of western Europe has one of the largest wave energy resources in the world; the theoretical potential of wave power in Britain is estimated at 50 TWh a year. Other major countries with a direct interest in wave energy are Japan, Norway, Denmark and USA, have estimated that a percentage ranging from 15%-50% of their total electric energy requirements, could resource from wave energy. Undoubtedly, a formal action undertaken by any key- country player, would accelerate worldwide participation and exploitation plans for international oceanic resources. Even at closed seas -like the Mediterranean, the wave energy potential is quite appreciable. The map shows estimated wave-energy levels around some selected coastlines of the world. Although these energy intensities do not quite reach those to the north-west of Scotland, they are still sufficiently high to be attractive, especially to those countries which are net energy importers (particularly Japan, USA, Canada and other western European countries).Sea waves are caused by the action of the wind on the water surface, in turn wind energy is caused by solar energy but with waves during the process of conversion the energy is concentrated more and more, from 100w/m2 up to a level of 100kw per wave front. Also wave energy is reliably present even during calm periods, unlike wind energy proper, so wave energy can also be considered as stored wind energy.
Wave energy performance measures are characterized by diffuse energy, enormous forces during storms, and variation over wide range in wave size, length, period, and direction. The copious variety and volume of this subject invention confirms the viability of wave energy conversion, yet, exploitation has only recently seriously considered prior technical development. The diffuse nature of waves requires a number of devices to generate large amounts of electricity. Large scale offshore devices and small scale shoreline devices have been ocean tested. The amount of ingenuity spent on wave energy capturing devices, has been truly profound. Starting from the simplicity of the OWC and ending to the complexity of the Salter's Ducks, the all around verdict has been that failure or unfeasibility, has put much more on the scales than clearly defined success. Undoubtedly, politics, state control and interweaved interests have contributed to a complex game, which our planet and hosted societies ends up paying. However, optimal and well tuned international research did not happen for wave energy. At this stage, we are bound to regard wave energy as being yet an explorative issue, whilst the danger for many assets of this exploration being money down the drain for some and, "clever business" for others, this remains one of the penalties of our system. Until a clear horizon appears where everybody seriously involved gets a chance to participate, wave energy will remain a designers' challenge.Given the speed at which we are using up fossil fuels, and the collapse of the nuclear industry in most countries, the world is going to encounter a famine of useful energy within the next 30 years, if we do not change our pattern of production and consumption. We need desperately to develop renewable sources, however uncertain the need may appear at times. The question of cost is important, but has been purposely overstressed and miscalculated. The first generation of wave energy devices, the estimated cost to the consumer of between 40c and 1$/kWh was far too expensive compared with about 5c/kWh for electricity generated by conventional fossil-fuel power stations. A second generation of devices, assessed in 1980, suggested costs of less than 10c/kWh. Improved wave power designs lead to further reductions in cost, whilst the real cost of fossil fuels rises. Perhaps, variety of uneducated opinions added to a very low public knowledge of pros and cons for wave energy, has eventually left a negative contribution to the applicable aspects of the field and its commercial projections. It is probably during the last 2 years that a decisive shift of public and industrial opinion has emerged. Whether this momentum could drive a significant change or not, it remains to be seen, yet, highlights already show that the Dane Sees Wave Energy Ousting Wind in 15 Years. Under a more moderate perspective, the global market for environmental goods and services is projected to rise to £440 billion by 2010. Shell estimates that 50% of the world's energy needs could be met by renewables by 2050. Wind power is already a £1.5 billion industry. By 2010 the global solar market could be worth up to £150 billion. It is therefore deducible that a wider commercial exploitation scenario for renewable energy schemes, should bring wave energy to the forefront. Besides strict commercialism planning, the apparent numerical observation on global energy consumption terms, could not fail from being a primary social issue; as education and standard of living improves in developing nations, protest for the grossly uneven distribution of resources -85% of the earth's inhabitants share a small proportion of the resources abundantly consumed by the 15%- will undoubtedly escalate. The issue of a wise proliferation of renewable energy resources seems to be one of the common ground solutions for both the developing, as well as the developed world.
World Wave Energy Potential -Major global power estimations-World Wave Energy Potential
- Detailed power estimations -
(available at Wavegen)http://www.wavegen.co.uk/resour.htm World Wave/Wind Energy Potential
- Geophysical distribution -
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