Preliminary assessment of near-shorewave energy potential in the Mozambique Channel

Abstract

This paper presents the results of a study of ocean wave energy in the Mozambique Channel, an open channel located in the Western Indian Ocean and oriented north-southwards. Weekly data of significant wave height and wave period, obtained from marine-analyst, on the web, were analysed in 10 selected coastal sites, 5 on each side of the channel. The channel receives swell waves from the extratropical South Indian Ocean in the south and monsoon-generated swell from the north, modified by trade winds and cyclones. The results indicate that the waves are highly variable ( 80%), with high (1.5–2 m on average), longer (8–20 s, on average), and more energetic (10–23 kW m 1 , on average) waves found in the southern part of the channel, followed by the northern part of the channel (1.2–1.4 m, 6–8 s, 6–7 kW m 1 , on average), with the middle part displaying a lower energy (6 kW m 1 , on average) wave climate. Peaks of high waves (up to 5 m) and high- energy waves (up to 90 kW m 1 ), attributed to storm conditions, were observed throughout the study period. Despite high variability in wave characteristics, the probability of waves exceeding the threshold values for viable exploitation for electricity production was about 61 and 63% for the western and eastern sides of the channel, respectively.