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 5m based on waverider buoy measured wave data. The study shows a significant reduction (∼10 to 27%) in wave power at 9m water depth compared to 30m and the wave power available at 5m water depth is 20 to 23% less than that at 9m. At 9m depth, the seasonal mean value of the wave power varied from 1.6kWmg-1 in the post-monsoon period (ONDJ) to 15.2kWmg-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 32kWm-1. At 9m water depth, the mean annual wave power is 6kWm-1 and interannual variations up to 19.3% are observed during 2009-2014. High wave energy ( > 20kWm-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.