Optimization of Low Head Axial-Flow Turbines for an Overtopping BReakwater for Energy Conversion: A Case Study

Overtopping-type wave power conversion devices represent one of the most promising technology to combine reliability and competitively priced electricity supplies from waves. While satisfactory hydraulic and structural performance have been achieved, the selection of the hydraulic turbines and their regulation is a complex process due to the very low head and a variable flow rate in the overtopping breakwater set-ups. Based on the experience acquired on the first Overtopping BReakwater for Energy Conversion (OBREC) prototype, operating since 2016, an activity has been carried out to select the most appropriate turbine dimension and control strategy for such applications. An example of this multivariable approach is provided and illustrated through a case study in the San Antonio Port, along the central coast of Chile. In this site the deployment of a breakwater equipped with OBREC modules is specifically investigated. Axial-flow turbines of different runner diameter are compared, proposing the optimal ramp height and turbine control strategy for maximizing system energy production. The energy production ranges from 20.5 MWh/y for the smallest runner diameter to a maximum of 34.8 MWh/y for the largest runner diameter.

MODEL EXPERIMENT AND FIELD TEST OF PW-OWC TYPE WAVE POWER EXTRACTING BREAKWATER

Many research studies on wave power conversion have been conducted in Japan over the past 30 years, but the outgrowth of these studies have yet to be put to practical use. In this study, medium-scale and large-scale hydraulic model experiments as well as prototype field test on a new oscillating water column with a projecting wall (PW-OWC) wave power extracting breakwater were carried out in order to investigate the efficiency of energy conversion. The primary energy conversion efficiency of the PW-OWC converter is about 10% larger than that of the standard OWC type used in the medium-scale experiments. The primary energy conversion efficiency of the large scale experiments is about 20-30-% smaller than that of the medium scale experiments. The secondary energy conversion efficiency ranges from 0.20 to 0.42 and becomes small when the wave period is short and the wave height is large.

Permanent Magnet Synchronous Generator Based Standalone Wave Power Conversion System for Sustainable Power Supply at Perhentian Island

In developing country like Malaysia, the development of islands is mostly related to the electric power availability. Because there are many islands in Malaysia where the power grid is not available. As an island surrounded by sea, wave energy can be considered one of the environmental friendly power generating sources for island communities. But, high dependency on weather conditions is the main drawback of wave energy source. To overcome this drawback; wave energy device, energy storage devices and the electronic converters need to be integrated with each other. This study presents a battery storage standalone oscillating water column wave energy conversion system for island electrification in Malaysia