Power Generation; Contribution from tidal waves
Gravitational forces between the moon, the sun and the earth cause periodic rising and lowering of ocean waters around the world; which result in tidal waves. Due to its much closer position to the earth, the moon exerts more than twice as great a force on the tides as the sun.
Advertisement
Consequently, the tide closely follows the moon during its rotation around the earth, producing diurnal tide and ebb cycles at any specific ocean surface. The height (amplitude) of the tidal wave is comparatively small in the open ocean, where it measures several centimetres in the centre of the wave, distributed over hundreds of kilometers.
Nevertheless, the tide can increase intensely, when it reaches continental shelves, bringing in its wake, large masses of water into narrow bays and river estuaries along a coastline. For example, the tides in the Bay of Fundy in Canada are the greatest in the world, and reach heights of between 16 and 17 metres near shore.
Tidal Energy
Tidal energy is formed through the use of tidal energy generators. These huge underwater turbines are placed in areas with high tidal movements, and are designed to capture the kinetic motion of the receding and rolling ocean tides to produce electricity. Tidal power has abundant potential for future power and electricity generation because of the enormous size of the oceans.
Ocean waves contain significant energy density and have substantial commercial potential, if the energy can be extracted using a reliable, environmentally friendly and cost-effective technology. Wave energy, which is a renewable, sustainable and a free source of energy, would have a vast impact on electricity production in the world; given that feasible solutions in terms of technology, economy and ecology are provided.
Tidal Wave Energy Converters
The following statistics make wave energy worthy of exploration to enhance power generation in Africa in general, particularly Ghana, which is experiencing a period of serious power outages;
• Oceans cover about 70 per cent of the Earth’s surface.
• The global wave energy potential is at least as big as that of hydro power. Different estimates range from 10,000 to 15,000 TWh per year worldwide.
• The utilisation factor for wave power – the ratio of average generated power to the installed power of the power plant – is expected to be as high as 50 per cent (4,380 h/year for a normal wave climate).
New and Renewable Sources of Energy
The fact that energy is the engine of economic growth can hardly be overemphasised. Considering the resolve to increase our Gross Domestic Product, it is pertinent to ensure that all sources of energy, which could be used as inputs for power generation, are explored. More often than not, one has the issue of cost or the level of availability of the energy source to grapple with. Like ignorance, which has proven to be more expensive than education or knowledge, the dearth of energy and for that matter electricity is sine qua non in the modern world. Why? We are surrounded by gadgets, gizmos, plant and machinery, which collectively make our lives interesting, exciting and adventurous. In this light, we should leave no stone unturned in making sure that we have available, reliable and adequate supply of power.
Currently, the comparatively big hydro sources of power in Ghana are exhausted. We also know that fossil fuels that we rely on to generate thermal power would be depleted one day. What are inexhaustible, are renewable energy sources like wind, tidal waves, solar, biogas, etc. Therefore,it is prudent for us to bite the cost bullet; and consider developing our renewable energy sources, with a view to utilising them to generate power. In light of this, the relatively unexplored renewable energy sources like tidal waves ought to be in ourprioritised energy mix for power generation. We must also not forget our demand side management, which are epitomised by energy efficiency improvement and energy conservation.
Local Efforts
A local company - TC’s Energy - is in the process of installing a pilot 14 MW Tidal Wave Power Plant at the confluence of the Volta River and the Gulf of Guinea, Ada Foah.This company will utilise Seabased Wave Energy Converters for the generation of power. The fact that this technology is scalable means that the capacity of the plant will be increased from time to time, before attaining an optimal nameplate value.
The writer is the managing director of EnerWise Africa. Writer’s e-mail is [email protected]