The utilization of renewable energy sources has become a crucial aspect of global energy strategies, promoting sustainability and reducing greenhouse gas emissions. Among renewable energy sources, the wave power and wind energy offer great potential for harnessing clean and renewable electricity. As the global population trend continues to increase, the demand for energy requirements becomes more significant due limited availability of natural resources. In response, alternative and sustainable energy sources and associated technologies have been under progressive development, encompassing hydropower, wind, wave, solar, bioenergy, geothermal, and marine energy. Offshore energy extraction from various renewable energy sources faces high operation and maintenance (O&M) costs, around one-third of total expenses, more than the onshore setups (Scheu et al., 2012). Consequently, generating power from a single marine energy source tends to have higher costs when contrasted with onshore renewable energy alternatives. Beyond the operational and financial challenges, addressing pertinent issues related to periods of no power output and the unpredictable nature of energy generation from these variable sources becomes crucial (Gaughan et al., 2020). However, the simultaneous utilization of various marine energy sources at a single offshore site holds the potential to address challenges posed by individual renewable energy systems. This integrated approach can enhance the overall efficiency and reliability (Astariz et al., 2016).
Assessment of wave energy resources have been conducted for different geographical regions in the world, utilizing wave data sourced from buoys, satellites, and numerical wave hindcasts, either individually or in combination. Regions include the Baltic Sea (Bernhoff et al., 2006), the Black Sea (Akpinar et al., 2013), and the Persian Gulf (Kamranzad et al., 2013) etc. Additionally, wave energy assessments have been conducted for regions such as Indo-Pacific (Kumar et al., 2021; Kaur et al., 2021), Canada (Dunnett et al., 2009), Malaysia (Nik et al., 2011), Portugal (Rusu et al., 2009; Mota et al., 2014), Taiwan (Chiu et al., 2013), and the United Kingdom (Neill et al., 2013). The study by Reguero et al. (2015) conducted an analysis of global wave power and its temporal variability during the period 1948–2008. Utilizing satellite wind data, assessments of wind resources were conducted for Europe (Hasager et al., 2015), the US Atlantic coast (Sheridan et al., 2012), and the South China Sea (Chang et al., 2015). Zheng et al. (2018) also carried out a comprehensive evaluation of global wind energy resources. Additionally, a global review of wind energy assessments was performed by Murthy and Rahi (2016). By using cross-calibrated wind data from various platforms, Zheng et al. (2013) examined the wind energy density across the global ocean. They observed prosperous regions situated in the western belts of the Northern Hemisphere (500–1000 W/m2) and in the Southern Hemisphere (800–1600 W/m2).
Limited attempts have been made to examine the wind and wave patterns in the Indian Ocean (Sardana et al.,2022; Krishnan et al.,2012; Kumar et al., 2013; Pogarskii et al., 2012). Numerous studies have focused on assessing either offshore wind (Gadad et al., 2016; Nagababu et al., 2017; Kumar et al., 2020) or wave power resources (Kumar et al., 2015; Patel et al., 2020) within the Indian Ocean region. One study investigated the wind-wave field across the Indian Ocean using a 12-year dataset of wind measurements from the National Centers for Environmental Prediction and the National Oceanic and Atmospheric Administration (NCEP/NOAA), along with wave data from the numerical wind-wave model (WAM). This study revealed that the average wave height increases by 1% each year (Pogarskii et al., 2012). Shanas et al. (2015) noted a declining trend in both mean and extreme wind speeds for the Arabian Sea (AS) and the Bay of Bengal (BoB). Interestingly, during this period, a contrasting trend of increasing extreme wave height emerged from a 33-year analysis of wind and wave data (Sadhukhan et al., 2020). In a separate study, it was observed that wind power varies as one goes higher above the surface due to its non-stationary nature (Calif et al., 2012).
In a recent investigation, the reanalysis of wave data unveiled a consistent annual increase of 0.4% in global wave energy since 1948, attributed to ocean warming (Reguero et al., 2019). Gadad et al. (2016) explored offshore wind energy potential at Karnataka, India, utilizing OceanScat (OSCAT) scatterometer wind data. Their findings reveal India's greater capacity for harnessing wind energy from offshore sources (up to 450 W/m2) compared to onshore sources (up to 300 W/m2). Examining wave resources across nineteen distinct locations within the Indian Shelf seas using ERA-Interim data, Kumar et al. (2015) conducted a comprehensive wave energy analysis. Additionally, a meticulous assessment of wave energy exploration along the Indian coastline employing high-resolution hindcast data from the WAVEWATCH III (WWIII) model indicated India's wave potential ranging from low to moderate (up to 12 kW/m). Relative to European nations, where offshore wind potential can reach up to 1500 W/m2 and wave potential up to 150 kW/m, India's offshore wind and wave potential is comparatively constrained. Considering this situation, the combined utilization of wind and wave resources emerges as an advantageous strategy, as elaborated in the earlier sections.
This research investigated the combined potential of wind and wave energy at six key port locations situated along the eastern and western coasts of India. It delved into the seasonal climatology and variability patterns of mean significant wave height (SWH) from swells (Hs) and wind-seas (Hw), as well as mean wind speed and wave period across the North Indian Ocean (NIO) region. Additionally, the study explored the seasonal climatology and variability of extreme SWH from swells (Hmaxsw), SWH from wind-seas (Hmaxws), maximum wind speed (Wmax), and wave period (Pmax), along with extreme wave power and wind energy in the NIO region. The substantial impact of long-term resource variations on strategic planning has been well-established in previous studies (Kamranzad et al., 2020; Sreelakshmi et al., 2020). Therefore, leveraging ERA5 reanalysis data, this study analyzed seasonal trends in wind and wave energy within the NIO, aiming to provide essential support for long-term planning initiatives and sustainable development endeavors.