Wave power

About: Wave power is a research topic. Over the lifetime, 2671 publications have been published within this topic receiving 41439 citations. The topic is also known as: wind wave energy & sea wave energy.

Wave energy resource assessment based on satellite observations around Indonesia

Abstract: A preliminary assessment of wave energy resource around Indonesian’s ocean has been carried out by means of analyzing satellite observations. The wave energy flux or wave power can be approximated using parameterized sea states. Wave power scales with significant wave height, characteristic wave period and water depth. In this approach, the significant wave heights were obtained from ENVISAT (Environmental Satellite) data which have been calibrated. However, as the characteristic wave period is rarely specified and therefore must be estimated from other variables when information about the wave spectra is unknown. Here, the characteristic wave period was calculated with an empirical model that utilizes altimeter estimates of wave height and backscatter coefficient originally proposed. For the Indonesian region, wave power energy is calculated over two periods of one year each and was compared with the results from global hindcast carried out with a recent release of wave model WAVEWATCH III. We found that, the most promising wave power energy regions around the Indonesian archipelago are located in the south of Java island and the south west of Sumatera island. In these locations, about 20 – 30 kW/m (90th percentile: 30–50 kW/m, 99th percentile: 40–60 kW/m) wave power energy on average has been found around south of Java island during 2010. Similar results have been found during 2011 at the same locations. Some small areas which are located around north of Irian Jaya (West Papua) are also very promising and need further investigation to determine its capacity as a wave energy resource.

Spatial and temporal variations of wave energy in the nearshore waters of the central west coast of India

Abstract: . Assessment of wave power potential at different water depths and time is required for identifying a wave power plant location. This study examines the variation in wave power off the central west coast of India at water depths of 30, 9 and 5 m based on waverider buoy measured wave data. The study shows a significant reduction ( ∼ 10 to 27 %) in wave power at 9 m water depth compared to 30 m and the wave power available at 5 m water depth is 20 to 23 % less than that at 9 m. At 9 m depth, the seasonal mean value of the wave power varied from 1.6 kW m−1 in the post-monsoon period (ONDJ) to 15.2 kW m−1 in the Indian summer monsoon (JJAS) period. During the Indian summer monsoon period, the variation of wave power in a day is up to 32 kW m−1. At 9 m water depth, the mean annual wave power is 6 kW m−1 and interannual variations up to 19.3 % are observed during 2009–2014. High wave energy ( > 20 kW m−1) at the study area is essentially from the directional sector 245–270° and also 75 % of the total annual wave energy is from this narrow directional sector, which is advantageous while aligning the wave energy converter.

Consistency of wave power at a location in the coastal waters of central eastern Arabian Sea

Abstract: Wave energy assessment at a regional scale is required for planning installation of wave energy converters. Based on continuously measured wave data at 14-m water depth in the central eastern Arabian Sea from January 2011 to December 2017, the temporal distribution of wave power potential is studied in detail along with statistical analysis of the wave power and wave parameters. Long-term variability in wave power is examined based on reanalysis data from 1979 to 2017. The study also evaluates the wave power technologies, such as Oyster, WaveDragon, and WaveStar for the study location. Significant inter-annual variations in the wave power are observed from June to September due to the fluctuations in the Indian summer monsoon. The annual mean wave power is 7.85 kW/m with year-to-year variability up to 13% from 2011 to 2017. During 24.7% of the time (~ 90 days) in a year, the wave power is more than 10 kW/m and is less than 5 kW/m during 68% of the time in a year. Most (90.4%) of the available wave power is from a narrow band between west and southwest. A spatial variability of ~ 12% in the annual mean wave power is observed along the central eastern Arabian Sea based on the measured wave data at three locations in 14–15-m water depth. The study shows that WaveDragon and WaveStar energy converter produces the electric power during 81 and 85% of the time in a year, whereas Oyster gives output during 59% of the time. The capacity factor of WaveStar is high (27–34%) for the study area compared with other technologies considered in the study.

Non-linear Slack-Mooring Modelling of a Floating Two-Body Wave Energy Converter

Abstract: Most floating oscillating-body wave energy converters that have been proposed and developed so far are two-body systems where the power is extracted from the relative translational motion between the two bodies. As any floating device, floating point absorbers are subject to drift forces due to waves, currents and wind, and therefore need to be kept in place by a proper mooring system. The mooring cables can be approximately modelled as catenary lines in a quasi-static analysis. The use of a time-domain analysis allows for nonlinear mooring forces of slack chain cables to be considered. Numerical results for motion, mooring tensions and absorbed power are presented for a two body system consisting of a hemispherical floater and a submerged body and slack bottom moorings, for regular and irregular waves. Comparisons are given with the unmoored two-body heaving system, the moored heaving twobody system and with the simplified one body linear PTO model. Results show the possibility of occurrence of low-frequency horizontal oscillations of large amplitude, and non linear motions, even for regular waves. Some differences are seen in comparison with the simplified one body model and with the heave two-body system. The moorings were found not to affect very significantly the power absorbed.