Yasushi Higo

Validation of the Index to Determine Design Parameters of a WEC for the Cost Optimization of a Wave Farm

An index to estimate the cost of electricity (COE) generated by a wave farm from the design parameters of a wave energy converter (WEC), such as the body size and the generator capacity, was examined to show the validity of index value in this study. The validation tests are performed for three different wave farm settings at three different locations.The result displays the potential of index to capture the trend of COE value especially when the wave farm size is small. The calculation result of COE reveals that the parameter combination to give better profitability is determined by the balance between WEC construction fee and installation fee. So, it would be different from the optimum size to have the best energy conversion efficiency. It also explains the shift of parameter combination to give the better profitability when the size of wave farm is changed. However, the index contains certain level of error because of the lack of this feature. Therefore, the error becomes larger when the size of wave farm becomes larger. As a result, it was found that the modification of the index is needed to improve the accuracy by including the cost related to the number of buoys in the wave farm.Copyright

A Very Simple Index to Determine Design Parameters of Wave Energy Converter for Wave Farm Cost Optimization

Expansion of the deployment site of wave power generation plant to lower wave energy sites is a key for the market size expansion, which contributes the reduction of the cost of electricity. However, it is not easy to take place from the economical view point since the revenue is limited by the low wave energy. Also, since current prototypes are designed for very energetic seas, they are too large for milder conditions. In order to improve the economic feasibility, design parameters of wave energy converter (WEC) have to be adjusted to the existing wave condition at the site. However, no method exists for this purpose. A new index to determine parameters of WEC for having better economic feasibility in wave farm is introduced in this work, so that the designer can see the relative superiority among parameter combinations without conducting complex economic feasibility studies. The index value was examined through an economic feasibility study of hypothetical wave farm project at Japan and found that it reasonably indicates the level of cost of electricity.Copyright