Planning and development of ocean wave energy conversion

Abstract

At the beginning of the 21st century, global environmental problems, including global warming, were attracting attention worldwide. In these circumstances, momentum is building across the world for the effective utilization of clean and renewable natural energy sources. The ocean is the world’s largest collector and storage medium for solar energy. At the same time, it produces various forms of energy while interacting with the atmosphere. Wave energy is an indirect and condensed form of solar energy. Wave gathers their energy from the wind. Wave gather, store and transmit this energy thousands of kilometers with little loss. As long as sun shines, wave energy will never be depleted. It varies in intensity, but it is available throughout the day and year. The wave energy conversion activities should be preceded by the estimation of wave power potential which needs the collection of wave data all along the coastline of the countries. Assessing the performance of a Wave Energy Converter (WEC) that is, predicting the effective amount of energy converted from the incident wave field over certain period of time in nominal operation conditions necessarily requires a precise knowledge of the local wave climate. The main wave characteristics are commonly given in terms wave height, period, direction of propagation and power. The power in wave can be expressed by the formula P = 0.55 H2s T, kW per meter of crest length, where Hs, is the significant wave height in meter and T, is wave energy period in seconds. However, it is rarely possible to measure data in a proposed sea area over a long period of time, and to use the data in setting the environmental condition parameters within which such devices will be expected to function. As a result, short-term data and water-related data supplied by weather stations concerning the proposed sea area are often used when designing WEC devices. Wave power plant design, for operation in a largely random, highly irregular and sometimes very harsh environment, is a great challenge. Survivability is a more vital issue than in any other renewable energy technology, as could be learned from the experience with prototypes. Environmental conditions are very important factors that must be taken into account when designing WEC devices. This paper aims to describe the importance of data, data collection methods, important parameters to estimate the potential wave energy, available wave energy conversion methods, economic and environmental impacts.