Browsing by Author "Alqahtani, Saad"

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Frequency Stability in Low Inertia Power Systems with High Renewable Generation Integration
(Cardiff University, 2024-10) Alqahtani, Saad; Cipcigan, Liana
The pursuit of a more sustainable and environmentally conscious future has led to the progressive integration of non-synchronous Renewable Energy Sources (RESs) into power systems worldwide. However, integrating these non-synchronous RESs, such as wind and solar power, presents significant technical challenges due to their different operational characteristics compared to conventional synchronous generators. Non-synchronous RESs generate electricity through power electronic inverters rather than directly synchronizing with the grid frequency. Unlike traditional generators, they do not have large rotating masses that provide inertia, which is crucial for stabilizing grid frequency. Consequently, the absence of inherent inertia in non-synchronous RESs makes managing grid stability more challenging, especially as their share in the energy mix increases. The Kingdom of Saudi Arabia (KSA), in alignment with this global endeavour, has embarked on an ambitious journey to incorporate substantial amounts of non-synchronous RESs into its national grid. This thesis is dedicated to examining the general and regional consequences of this transition, particularly focusing on how high integration of non-synchronous RESs impacts the frequency stability of the KSA's national grid. Five studies are conducted to address various aspects of this complex interaction. The initial study lays the groundwork by developing future energy scenarios (Low Progression, Medium Progression, and High Progression) for 2025 and 2030, providing a foundational framework for subsequent analyses. Building upon this foundation, the second study estimates future power system inertia to evaluate long-term dynamic frequency response under high inverter-fed RESs. This inertia estimation methodology forms the basis for assessing long-term dynamic frequency response under high inverter fed RESs, revealing insights into the system's resilience and stability. Another challenge that this research is addressing, is the impact of renewable energy sources on the stability of the KSA power system at the regional level. To comprehensively evaluate this impact, an adaptive dynamic model of the KSA national grid is developed and validated in the professional power factory platform, considering regional operation area characteristics. This detailed model enables a thorough evaluation of how RESs integration affects stability across different regions of the system. iii In study four, a comprehensive analysis of the KSA system frequency stability in 2025 and 2030 under predesigned future energy scenarios was conducted, emphasizing the regional impact of RESs integration on frequency stability. This study provided vital insights into the frequency response dynamics of the power system under different scenarios, highlighting areas of vulnerability and potential challenges arising from high levels of RESs penetration. Finally, building upon the findings of study four, a methodology for selecting the optimal sizing of utility-scale Battery Energy Storage System (BESS) is developed to enhance frequency response, particularly in areas identified as having weak stability. The findings underscore the importance of integrating BESS into future energy planning strategies to ensure the reliable operation of power systems amidst increasing penetration of RESs. These studies collectively contribute to a deeper understanding of the challenges and opportunities associated with RESs integration, offering valuable insights for future energy planning and system operation. This research framework not only offers a holistic view of RESs integration challenges but also facilitates the development of strategic solutions. The findings emphasize the critical role of accurate scenario planning, inertia estimation, regional analysis, and BESS optimization in achieving a resilient and stable power system amidst the growing influence of non-synchronous renewable energy sources.
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THE INTRICATE RELATIONSHIP BETWEEN TOURISM AND HEALTH: A SYSTEMATIC REVIEW
(University of Surrey, 2024-02-26) Alqahtani, Saad; Chen, Jason
Background: There exists a direct relationship between tourism, travel and health. According to the United Nations World Tourism Organization (2015), tourism can directly promote health and wellness through the provision of strategically reinvented health-related services. It is from this perspective that the rise of medical tourism became apparent. Medical tourism is the practice of travelling abroad for medical services. Under normal circumstances, wellness tourism is aimed at advancing the motivation of relaxation, mental therapies, and an improved quality of life for the tourists. There is a direct link between travel/tourism and health as the former directly impact an individual’s state of health in association with social, physical and mental wellbeing (Alipour et al., 2020: Lee et al., 2020). Moreover, according to Hartwell et al. (2018), tourism presents a direct influence on psychological, emotional, spiritual and cognitive dimensions of a normal person’s wellbeing. The above arguments by Alipour et al. (2020) and Lee et al. (2020) support a previous finding indicating that there is a causal relationship between tourism and health based on the observation that older tourists tend to be healthier and active as compared to non-tourists (Ferrer et al., 2016). Research aim: To identify, evaluate, and synthesise evidence from the published research on the relationship between tourism and health to set precedence for the future research on the identified gaps. Research objectives: 1) To summarise and synthesise the existing evidence on the relationship between tourism and health 2) To identify knowledge gaps in the extant literature in relation to the nexus between tourism and health 3) Establish precedence and set a background for the future research on the relationship between tourism and health 4) To make relevant recommendations that will inform decision-making practices by companies operating within the tourism sector on the provision of health-oriented services 5) To make recommendations that will influence the perceptions and decisions made by tourists in visiting destinations solely for meeting their health and wellness needs Methods: Philosophy: The interpretivist-constructivist was preferred because it tends to focus on plausibility, authenticity, justifiability, coherence, criticality, comprehensibility, compulsion, and assessability of a certain topic of interest. The interpretivism-constructivism approach is justified because the researcher is aiming to derive meaning from the existing secondary sources on the relationship between tourism and health. Design: The systematic review design was used to determine the extent and nature of evidence published on the aspects of tourism and health. Search process: The online databases from which the evidence was retrieved include MEDLINE (PubMed) and Google Scholar. The combined keywords were [Tourism OR travel OR vacation] AND [health OR well-being OR medical OR mental health OR physical health OR wellness] AND [impact OR effect OR association] AND [population OR community OR individual]. The PRISMA 2020 flow diagram was used as a guide to the evidence search process. Quality appraisal: The mixed methods appraisal tool (MMAT) was adopted in the appraisal of methodological quality of the included studies. Results: The initial search retrieved 534 reports that were evaluated based on the inclusion/exclusion and eligibility criteria leading to the final list of 15 articles (2 qualitative and 13 quantitative). Evidence was then retrieved from the 15 articles. The intricate relationship between tourism and health was revealed in four perspectives. First, medical tourism positively impacts tourists’ physical and psychological health, wellness in the form of positive emotions and life satisfaction due to the tourist’s autonomy, experience, and intrinsic motivation. Second, higher perceptions of community well-being arose from greater economic performance of medical tourism. Given the perceived positive impacts of tourism, the community’s attitudes toward medical tourism influenced the overall satisfaction with the practice and eventually, the community’s willingness to pay higher taxes and participate in the promotion of medical tourism. Third, the negative health impacts of tourism include increased crime rates, overcrowding and congestion that heighten the residents’ stress levels leading to ill health. Finally, medical tourists’ require to be motivated, and the factors that influence their intentions to visit a destination include follow-up care, advanced and affordable medical technology, tourism activities for companions, strong government support, extra support for patients, price, variety of treatments, accessibility and service, and infrastructure at the destination, perceived risks, and medical facilities associated with the destinations. The factors that influence revisit intentions are health evaluation, international certified doctors, doctors’ expertise, quality of medical treatment, advanced medical treatment, high healthcare quality, hospital contact information, waiting time until treatment, and availability of medication. Limitations: The scope of the review was limited as only 15 articles were included. There was inadequate theoretical development in the studies due to failure to incorporate key elements pertaining to this relationship such as public awareness and tourism campaigns in cementing medical tourism, responding to health crises such as pandemics, the dynamics of medical tourists’ behaviours during pandemics, the role of policy, regulation, technology, ethics and sustainability as fundamental pillars of medical tourism. Moreover, methodological limitations were evident in the sampling strategies and data collection methods used. Most of the studies adopted purposive and convenience sampling strategies, which are non-probabilistic. This introduced sampling bias that affected the credibility and generalisability of the results. Additionally, interviews are subjective while cross-sectional designs do not depict causal relationships. Implications for practice and future research: This review positively contributes to the tourism industry. Since the number of health-conscious visitors is on the rise, businesses with stake in tourism, hospitality, and travel sectors should position themselves to offer services that appeal to such tourists. They can segment their clients according to their needs and invest in the required services and products to generate more revenues. Furthermore, since the review outlines the factors that motivate medical tourists to either visit or revisit an attraction destination, it is beneficial to the destinations that offer health and wellness services. These destinations will adopt the factors that motivate medical tourists to visit, and as a result, improve their competitiveness in that sphere of service provision. This will open up innovation in the sector in relation to enhancing medical tourism. The future research should pursue additional variables including the role of the tourism sector in responding to health crises such as pandemic, the dynamics of medical tourists’ behaviours during pandemics, the role of policy, regulation, technology, ethics and sustainability as fundamental pillars of medical tourism. The future research should consider investigating this relationship from the lenses of multiple motivational theories including Maslow’s Hierarchy of Needs, Theory of Planned Behaviour (TPB), Self-Determination Theory (SDT), and Expectation Confirmation Theory (ECT). Mixed methods, experimental, and quasi-experimental designs are recommended for future research to establish causal relationships among variables developed from the relationship between tourism and health. Conclusions: The review posits that tourism is not only for leisure purposes but serves even more interesting purposes such as promotion of health and wellness. It is evident that medical tourism is on the rise and its social, wellness, cultural, and economic value is acknowledgeable. Therefore, more efforts should be invested in medical tourism for the benefit of businesses, visitors, healthcare systems, and communities and their economies. Nevertheless, research is underdeveloped in this area, and thus, justifies the need for continued research to fill the existing knowledge gaps.
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