*4.1. The ICFPICS Demonstrated for Four Case Studies*

Four distinct Pacific Islands were selected to demonstrate how the ICFPICs can be utilized, and the potential challenges identified for every island are shown in Figures 4–7. The process included researching each item presented in the ICFPICs cluster diagram (Figure 2) and verifying if it was considered as a potential challenge. The analysis was based on country reports, regional reports, and official statements. Every item in Table 2 either posed a threat to a wave energy project on the island or could not be further verified; items that are not included were found to be non-threatening.

**Figure 4.** Map for Tubuai demonstrating challenges found through spatial analysis. The shipping routes are shown using a green color scale to represent the number of vessels that traveled through this area for one year (each raster has a 920 m<sup>2</sup> area). Artisanal fishing activities are present in the blue shaded areas. The remaining layers are colored separately, red for hurricane tracks, yellow for marine protected areas, light green for coral reefs, and pink for marine world heritage sites.

Tubuai is part of the Austral island group in French Polynesia, Viti Levu is the main island of Fiji, Rarotonga is the main island of the Cook Islands, and 'Eua is part of the Kingdom of Tonga. The analysis results demonstrate how each island has different characteristics and, consequently, different challenges. All four islands have established renewable energy targets, no signs of political instability, and no electricity grid available; however, since marine energy is relatively new, there is no information regarding government support. Cost of energy and risk are both unknown factors since resource assessment, risk assessment, and further analysis are needed. Additional common challenges were found to be the distance from the main markets, causing logistics issues, a lack of marine energy regulations, the presence of coral reefs, potential natural hazards, and a rich marine biodiversity environment. It is also important to note that access to funds and local acceptance will rely

on the outputs from resource assessment and cost analysis, thereby being a potential barrier. The maps presented here were created using databases for protected areas [29], marine World Heritage Sites [30], coral reefs [31], hurricane tracks [32], and marine activities [33].

**Figure 5.** Map for Viti Levu demonstrating challenges found through spatial analysis. Color layers as per explained in Figure 4's caption.

**Figure 6.** Map for Rarotonga demonstrating challenges found through spatial analysis. Color layers as per explained in Figure 4's caption.

**Figure 7.** Map for 'Eua demonstrating challenges found through spatial analysis. Color layers as per explained in Figure 4's caption.

Tubuai is the most remote island among the selected sites, it is located in the south of French Polynesia with a population of approximately 2200 [34]. Due to the small population size, the energy demand is also low, and the technological aspects of wave energy might be a challenge. The Tubuai harbor has been expanded in 2014, yet, it has limited uses and might not accommodate large shipments. Even though there are touristic and recreational sites on the island, the influx of tourists is low; in 2013 it was recorded a total of 1899 visitors [34] for all Austral islands combined. The Historical Hurricane Tracks by the National Oceanic and Atmospheric Administration shows that there have been 11 storms in a 100 km radius around the island since 1970; only three so far have been classified as hurricanes. Additional challenges are the fishing activities, a large coral reef area surrounding the island, a proposed Marine Reserve zone for the Austral islands [35], artisanal fishing activities nearshore, high influx of vessels to the North, and the fact that French Polynesia is a Dependent Territory.

Tubuai is part of the Austral Island group in French Polynesia, Viti Levu is the main island of Fiji, Rarotonga is the main island of the Cook Islands, and 'Eua is part of the Kingdom of Tonga. The results of the analysis demonstrate how each island has different characteristics and, consequently, different challenges. All four islands have established renewable energy targets, no signs of political instability, and no electricity grid available; however, since marine energy is relatively new, there is no information regarding government support. Cost of energy and risk are both unknown factors since resource assessment, risk assessment, and further analysis are needed. Additional common challenges were found to be the distance from the main markets, causing logistics issues, a lack of marine energy regulations, the presence of coral reefs, potential natural hazards, and a rich marine biodiversity environment. It is also important to note that access to funds and local acceptance relies on the outputs from resource assessment and cost analysis, thereby being a potential barrier. The maps presented here were created using databases for protected

areas [29], marine World Heritage Sites [30], coral reefs [31], hurricane tracks [32], and marine activities [33].


**Table 2.** Identified challenges for each island based on the ICFPICs.

Tubuai is the most remote island among the selected sites; it is located in the south of French Polynesia with a population of approximately 2200 [34]. Due to the small population size, the energy demand is also low, and the technological aspects of wave energy might be a challenge. The Tubuai harbor was expanded in 2014, yet it has limited uses and might not accommodate large shipments. Even though there are touristic and recreational sites on the island, the influx of tourists is low; in 2013 a total of 1899 visitors were recorded [34] for all Austral Islands combined. The Historical Hurricane Tracks by the National Oceanic and Atmospheric Administration shows that there have been 11 storms in a 100 km radius around the island since 1970; only three so far have been classified as hurricanes. Additional challenges are the fishing activities, a large coral reef area surrounding the island, a proposed marine reserve zone for the Austral Islands [35], artisanal fishing activities nearshore, a high influx of vessels to the North, and the fact that French Polynesia is a dependent territory.

Viti Levu is the largest island in Fiji and, therefore, an important place for social and economic activities. As of 2017, all eight provinces of Viti Levu combined (Ba, Ra, Nadroga-Navosa, Naitasiri, Tailevu, Namosi, Rewa, and Serua) accounted for 662,205 inhabitants [36]. In addition to the tourism and fishing industries, there is a possibility of aquaculture and deep-sea mining activities. Due to its development and high population status, Viti Levu has seaports, an electricity grid, high demand, and expertise available. Nevertheless, Fiji's geographical location makes it susceptible to environmental hazards; cyclones are a common occurrence, and there have been 45 storms in a 100 km radius around the island since 1956, including two category 5 hurricanes. Further challenges include the presence of a cultural World Heritage Site named Levuka Historical Port Town [37], a significant coral reef zone, several active shipping routes surrounding the island, and several marine protected areas. Additionally, the presence of the Fijian Navy and the location of its fleet should be considered for any offshore development. Despite the technological and economic advantages, Viti Levu is bound by environmental, legal, and social challenges.

Even though Rarotonga is the main island of the Cook Islands group, it has a small population size of approximately 10,572, according to the Cook Islands Demographic Profile 2006–2011 [38]. The economic stability is undefined, as are any feed-in tariff schemes or government programs to subside renewable energy. For the social aspect, there are potential sites for deep-sea mining in the exclusive economic zone, fishing activities, touristic attractions, recreational sites, nearshore corals, and navigation routes in the west, east, and south. Unlike Viti Levu, Rarotonga is not at the risk of intense hurricane events; nevertheless, there have been 21 storms tracked in a 100 km radius that should be considered, even though they were mostly tropical storms. Lastly, the Cook Islands are dedicating their entire exclusive economic zone, Marae Moana, an area of 1.9 million square kilometers (550,000 square nautical miles) to protection, conservation, and integrated management [39], which might lead to conflicts with the legal, environmental, and social sectors.

The last site, 'Eua, stood out among the selected islands due to having fewer potential challenges. 'Eua has small tourism, fishery, and maritime sectors; it also has a wellmaintained electricity grid, a seaport, and the possibility of a feed-in tariff scheme. When it comes to the electricity supply factor, the small population size of fewer than 5000 residents might become an issue. Thus, one of the key elements to bring wave energy to 'Eua is balancing the energy output around the local demand to justify costs. The ICFPICs also identified possible challenges related to the presence of protected areas on the island, the need for expertise, and annual hurricane occurrences. Since 1958, there have been 47 category 1 or above hurricanes, which also included 3 category 4 hurricane events. Lastly, artisanal fishing activities are present in the west and east of 'Eua, as well as a high influx of vessels towards the west and south of the island. However, there are viable sites nearshore in the south that could be explored, especially considering that higher wave energy resources are found within this area.

In these examples, each island presented different challenges in the economic, social, technological, environmental, and legal categories, demonstrating the diversity of the Pacific Island countries. For instance, it would be particularly difficult to bring wave energy to Tubuai due to technological and environmental constraints being prevalent. Nevertheless, larger islands such as Viti Levu and Rarotonga can still present challenges, such as environmental hazards and conflicts of use of the offshore area. If we consider the minimum distance to avoid the obstacles presented in Figures 4–7, 'Eua has the lowest at 0.1 km, Rarotonga has the highest at 378.35 km, while Tubuai and Viti Levu have, respectively, 2.17 km and 1.39 km minimum distance. This means that 'Eua could potentially have onshore, nearshore, and offshore wave energy converter devices, increasing the diversity of options.

### *4.2. Further Analysis of 'Eua Island*

The ICFPICs was applied for an in-depth analysis of the island of 'Eua. Furthermore, data obtained from Tongan governmental agencies and local institutions were used for this analysis to increase representation reliability. Data related to the fisheries, biodiversity, and tourism sectors were taken from Ministry of Fisheries [40], Marine and Coastal Biodiversity Management in Pacific Island Countries (MACBIO) [41], and Ministry of Tourism [42] sources, respectively. Each category from the ICFPICs is further explained below.

**Political:** Tonga experienced serious rioting in the capital Nuku'alofa in 2006 but adopted a democratic constitution in 2010 and appears to have returned to its earlier pattern of long-term political stability [43]. In addition to that, Tonga has already committed to achieving 50% renewable energy generation by 2020 and 70% by 2030, which is a motivator for wave energy to be further studied.

**Economic:** The cost of energy and the qualitative and quantitative risks need to be assessed in order to analyze if economic factors will be an obstacle for wave energy. Nevertheless, the final results will also depend on how the cost range compares to the current energy sources and to the average costs in the world; the cost alone cannot convey enough information, which is why the cost and risk analysis are necessary steps to identify any potential concerns.

**Social:** There are no documented offshore mining and aquaculture activities or heritage sites for the island of 'Eua. There are, however, villages that date back thousands of years and have cultural value, including Ohonua, Tufuvai, Pangai, Houma and Ha'atua. The island has only one port, which is situated at 'Ohonua and connects 'Eua to the Tongatapu island, the main route of the local ferries. When it comes to fisheries, 'Eua does not have a significant export rate and according to the latest statistics [44], only 12% of the households practice fishing for consumption or for sale. Nevertheless, there are sites near 'Eua using fish aggregating devices that have been deployed to increase fish production. Lastly, because of the presence of humpback whales, 'Eua is a fairly touristic island, with touristic activities being mainly whale watching, cave diving, and snorkeling.

**Technological:** The electrification rate for the Kingdom of Tonga is high and close to 100%, which also includes 'Eua. The network in 'Eua was also rebuilt in 2017 and was able to withstand Cyclone Gita, according to the TPL Annual Report from 2018 [45]. Therefore, grid-related issues are not a main concern. They also have the 'Ohonua port that serves as a navigation route between islands and for cargo transportation, which can be used for WEC shipments and related services. When it comes to expertise, however, there might be a lack of qualified professionals to work on the installation and maintenance of a WEC, considering that offshore development is non-existent in 'Eua. This would require additional funds but would open job opportunities and motivate public acceptance.

**Environmental:** 'Eua is situated in an area where hurricanes are relatively common occurrences. The cyclone season in Tonga is from November to April, however, the peak time for tropical cyclones in Tonga is from January to March with most events occurring in February [46]. The presence of cyclones should be accounted for in risk quantification and the cyclone season should be avoided in installation and maintenance procedures. Biodiversity is also another potential issue, with the humpback whales pathing around Tonga once a year from July to October, including around 'Eua. Pelagic sharks are also present on this island and are protected by the Kingdom of Tonga National Plan of Action (NPOA) Shark Plan [47]. In regard to corals, 'Eua has low coral reef resources, which are limited to the shallow areas around the island.

**Legal:** There are few regulations for marine energy in Tonga considering the lack of projects in this field. There are, however, important policies related to renewable energy, including: Renewable Energy Act 2009, Electricity Act 2007, Environment Impact Assessment Act 2003, Spatial Planning and Management Act 2012, and Petroleum Act. There are no documented maritime zones for 'Eua and there is also no military base in this area, which should not pose any risk to the project in terms of conflicts of use. The EEZ of 'Eua is relatively large, and it is unlikely that any wave energy development would trespass this area. There are, however, two marine protected areas in the island: 'Eua National Park and Tufuvai.

To better understand the boundaries for wave energy on the island of 'Eua, a map was created to add important locations found through the ICFPICs. The factors that could be mapped are present at Figure 8, which includes locations for fishing spots, touristic and recreational spots, important villages, the 'Ohonua port, and the ferry route between Tongatapu and 'Eua. Areas where the presence of humpback whales and pelagic sharks have been observed were also added, as well as the coral reef sites. Since the 'Euan population is mostly concentrated on the west coast, while a large part of the east coast is within the 'Eua National Park limits, the east coast was not considered for site selection. Four sites representing the north, northwest, southwest and south were selected as potential WEC sites and are shown as "Analysis Points" on the map. The selection process included bathymetry analysis as well as proximity to the main populated districts. Table 3 provides an overview of the local wave climate and wave energy resource for each point, using annual climatology data from the CAWCR wave hindcast [48].


**Table 3.** Wave climate and wave energy parameters for each point.

Points 1 and 2 have the most constraints, being surrounded by fishing areas, beaches, and pelagic sharks. Furthermore, point 2 also has the port nearby, being in close proximity to the ferry route. The only obstacle identified for points 3 and 4 is the possible presence of pelagic sharks, which makes these sites the most suitable for wave energy harnessing in terms of feasibility factors. Presence of coral reefs should only be a concern for shallow areas nearshore, until approximately 5 m depth in most parts. Nonetheless, there is also the distance from grid-connected areas factor to be considered; point 4 is the furthest from any residential area and, therefore, requires longer transmission lines. When it comes to the physical resource, point 4 has the highest mean wave energy flux and the lowest inter-annual variability, being a strong candidate for a WEC, followed by point 3. Seasonal variability seems to be an issue for the most of 'Eua, including points 2–4.

**Figure 8.** Map of 'Eua containing important sites and possible constraints. The map graphically presents the result of the PESTEL analysis and the potential sites for a WEC.

#### **5. Conclusions**

The Pacific region has already been shown to be promising in terms of wave energy resources even while the external factors remain unknown. This study proposed a framework that has an essential role in identifying scenarios where wave energy is considered feasible, making it a useful tool for project developers and decision makers. Figure 9 summarizes the functions of the ICFPICs and how it relates to its final goal. The framework allows the user to identify potential challenges and external factors through the ICFPICs elements, facilitating the process of defining suitable sites based on the results found before committing resources for site-specific feasibility studies and technical assessments.

**Figure 9.** Diagram summarizing the functions of the ICFPICs.

It is recommended to conduct resource and cost analysis alongside the ICFPICs to assess the overall feasibility of a project. While the framework created here is useful for early assessments to provide a general overview of relevant factors, it should not replace further project stages such as environmental impact assessment, for instance. Given that the ICFPICs is flexible in its use and can tackle different issues, the user is also encouraged to adapt it to new locations and different marine energy technologies, such as tidal, current, and ocean thermal energy.

The four study cases presented earlier exemplified how the ICFPICs can find suitable locations and compare different scenarios for wave energy. All four islands are located in areas with high wave energy resources, nevertheless, several issues that could deem wave energy unfeasible were found. As a future step, there is value in 'Eua for wave energy harnessing, considering its favorable conditions found through a first assessment. Following this study, resource assessment, risk assessment, and cost analysis studies are suggested for 'Eua.

Possible obstacles found for wave energy in 'Eua are related to the local biodiversity, tourism, natural hazards, cost of energy, and economic risk. According to preliminary results, the coastal areas near Ha'atu'a (point 3) and Li 'Anga Huo 'A Maui (point 4) are recommended as potential WEC sites. Moreover, the levelized cost of energy (LCOE) should be quantified considering the risks of unplanned maintenance due to natural hazards, overhaul, wave climate variability, and uncertain shipping costs for the WEC infrastructure. The cost analysis also needs to include possible variability for the costs of a singular WEC device, as well as conversion rates and discount rates. Even though further quantitate analysis is necessary, with the ICFPICs it was possible to identify feasible scenarios for wave energy in different areas of 'Eua, as well as to characterize potential obstacles.

**Author Contributions:** Conceptualization, J.B.P.; funding acquisition, T.W.; methodology, J.B.P.; supervision, T.W.; writing—original draft, J.B.P.; writing—review & editing, T.W. All authors have read and agreed to the published version of the manuscript.

**Funding:** A part of this study was funded through the Science and Technology Research Partnership for Sustainable Development (SATREPS) program between Japan and Malaysia, titled "Development of Advanced Hybrid Ocean Thermal Energy Conversion (OTEC) Technology for Low Carbon Society and Sustainable Energy System: First Experimental OTEC Plant of Malaysia".

**Data Availability Statement:** Publicly available datasets were analyzed in this study. CAWCR Wave Hindcast can be found here: https://doi.org/10.4225/08/523168703DCC5 (accessed on 30 December 2021). The World Database on Protected Areas can be found here: https://www.protectedplanet.net/ en/thematic-areas/wdpa?tab=WDPA (accessed on 14 December 2021). The World Marine Heritage Sites can be found here: https://www.marineregions.org/ (accessed on 13 December 2021). The Global distribution of warm-water coral reefs can be found here: https://doi.org/10.34892/t2wk-5t34 (accessed on 15 March 2022). The NOAA's International Best Track Archive for Climate Stewardship can be found here: https://www.ncei.noaa.gov/products/international-best-track-archive?name= ib-v4-access (accessed on 25 January 2022). Marine Activities data can be found here: https://knb. ecoinformatics.org/view/doi:10.5063/F1S180FS (accessed on 14 December 2021).

**Acknowledgments:** The authors would like to acknowledge SATREPS and its members, as well as The University of Tokyo and our research group "Applied Physical Oceanography" for their support during this study. Lastly, we would like to acknowledge the Kingdom of Tonga for recognizing this study and providing a research permit.

**Conflicts of Interest:** The authors declare no conflict of interest.

#### **Appendix A**
