The global shift toward renewable energy sources has been accelerating due to the need to reduce carbon emissions and environmental pollutants responsible for climate change. In recent years, the implementation of solar energy systems, particularly floating photovoltaic (FPV) systems, has exceeded expectations. Additionally, PV module prices have dropped by approximately 90% over the past decade, making solar energy increasingly attractive to investors. As per capita electricity consumption rises each year, many island nations struggle to meet their energy demands consistently. The logistical challenges and maintenance of power lines from the mainland, the high cost and upkeep of diesel generators, and the falling prices of solar technologies make FPV systems an increasingly viable alternative. Land-based solar systems require extensive land use, rendering large areas unusable for extended periods—a major drawback. Concurrently, the preservation of water in dams and freshwater sources has become essential due to global warming. However, any such preservation efforts must not harm natural ecosystems, particularly aquatic life. The FPV system designed in this study was developed to allow sunlight penetration without severing the water-air relationship, ensuring minimal ecological impact. Globally, two primary FPV system designs have emerged: one where solar panels are directly mounted on floating pontoons and another where metal frameworks support the panels, which float via pontoons. This thesis employs the latter approach. Detailed information is presented regarding three different FPV system designs and the challenges encountered under harsh weather and wave loads, such as those in Büyükçekmece Lake, as well as their impact on system performance. The key feature of the presented designs is their environmentally friendly nature—they reduce evaporation without disrupting sunlight penetration or water flow and minimize ecological interference. There is a notable lack of FPV applications under extreme meteorological conditions worldwide, as most systems are installed in calm waters, making this study particularly significant. Wave-induced loads due to wind were calculated using four different methods for wind speeds between 5 and 50 m/s. Some computed wave height values aligned with field observations, typically ranging from 1.5 to 3.0 meters. Resulting forces from twenty different wave heights were calculated using seven methods, yielding a wide data range that complicated decision-making. Additionally, anthropogenic alterations to lakebeds were found to create imbalanced load distributions that sometimes led to system failures—a previously undocumented phenomenon in the literature. The first system, based on readily available pontoons, highlighted the need for custom-designed floats. It also emphasized the importance of flexible connectors to cope with wave action. The second system incorporated specially designed pontoons allowing for system movement; however, limited flexibility due to single-axis movement reduced effectiveness. Nevertheless, the "sleeve" component connecting pontoons to the metal framework provided valuable experience in load transfer mechanisms. This thesis details FPV design, production stages, and installation procedures. It serves as a comprehensive guide for future researchers. Issues such as long-term damage from waves and solutions like using custom springs and rubber connectors for structural resilience are documented. The importance of thorough geotechnical studies and accurate anchoring system designs is emphasized. Shell formation on the submerged parts of pontoons was observed, leading to unexpected weight increases, underlining the need for thicker pontoons. Two unique pontoons were designed and tested during this study. The ultimate aim was to create a durable, flexible, and sustainable system capable of withstanding harsh weather and wave conditions. This was achieved in the third iteration, which remained operational over 20 months, proving its resilience. Literature reviews revealed no similar implementations under conditions as harsh as Büyükçekmece Lake's, making this contribution significant. Comparison between FPV and land-based systems showed comparable energy outputs in favorable designs. For instance, a 90 kWp FPV system produced 1974 kWh in May 2017 compared to 1985 kWh from a land-based system. However, a 30 kWp innovative system showed lower outputs due to fluctuating panel angles and electrical connection damage caused by harsh waves. Although more expensive due to R&D and lack of mass production, FPV systems are advantageous for not occupying land and preserving drinking water through reduced evaporation. This thesis, based on real-world observations and experiences, offers an eco-conscious design emphasizing maximum solar intake, minimal ecological disturbance, and sustainable floating solar energy development. In conclusion, this work offers a roadmap for developing robust FPV systems suitable for harsh environmental conditions. Its findings will aid researchers in constructing resilient FPV projects and contribute significantly to the literature on renewable energy in challenging climates.
DR. MUSTAFA KEMAL KAYMAK
In recent years, the impacts of climate change have been increasingly observed across the globe. Among these impacts—manifested as increases in the frequency and intensity of extreme meteorological conditions—rises in global average temperatures are the most pronounced. As temperature increases, so does the capacity of air to hold moisture, thereby intensifying evaporation from water reservoirs. This feedback mechanism, which reinforces itself positively, places accessible water resources at greater risk of drought worldwide. The principal cause of climate change globally is the emission of greenhouse gases (GHGs) into the atmosphere. While GHGs are emitted through various activities, fossil fuel-based energy production using coal and natural gas contributes the most. These gases also lead to air pollution, posing direct threats to public health. Although the global use of renewable energy has increased over the last 30 years with the aim of reducing GHG emissions, national policies geared toward development and economic prosperity have hindered substantial emission reductions. As a result, the dual threats of drought caused by global warming and the broader environmental impacts of GHG emissions have rendered renewable energy sources, especially wind and solar, essential for planetary and ecological sustainability. Among the most promising renewable energy applications is the deployment of Floating Solar Power Plants (FSPPs). FSPPs not only benefit from a thermal cooling effect on photovoltaic panels—enhancing solar power generation—but also reduce evaporation by acting as a barrier between sunlight and the reservoir surface. However, determining optimal siting locations for FSPPs remains a significant challenge worldwide. There is a notable lack of universal siting methodologies applicable to micro-siting of FSPPs on various water bodies, which differ in morphometric characteristics. Consequently, spatial resolution of commonly encountered natural constraints is required to generalize FSPP siting strategies globally. This study addresses this issue through a spatially detailed analysis of three primary environmental constraints—solar radiation, wind speed, and wave height—in the Manavgat Dam Reservoir, located in southwestern Turkey (Antalya province). The suitability for FSPP deployment was based on identifying areas with high solar radiation and low wind and wave activity. Solar Radiation: The first step involved computing annual total solar radiation across the entire reservoir area, accounting for topographic shading effects. The analysis was performed using the r.sun module within QGIS, a widely used GIS platform. This module calculates different radiation components and has been applied in large-scale renewable energy projects. Wind Speed: To resolve spatial wind patterns, particularly extreme events like storms and tornados observed in 2019, eight WRF/ARW model simulations were run using different physical parameterizations. The simulation with the highest statistical accuracy was selected. Since the WRF model outputs lacked sufficient spatial resolution over the reservoir, the WindNinja software—offering computational fluid dynamics (CFD)-based wind modeling—was used to generate a high-resolution (50m x 50m) spatial wind speed layer. Wave Height: Estimating wind-induced wave height required the prior calculation of fetch distance, a key variable for wave development. The Waves toolbox, an ArcGIS for Desktop extension, was used to generate fetch and wave height maps spatially across the reservoir, based on dominant wind direction and maximum wind speed. After individual analyses of these three environmental criteria, a fuzzy overlay method was applied to integrate them. This approach converted each raster-based constraint into a standardized scale (0–1), facilitating comparison across different physical units. The fuzzy sum operator was used to combine the layers, producing a composite map of Floating Solar Power Plant Suitable Reservoir Surface (FSPP-SRS). Findings revealed that the southern areas of the Manavgat Reservoir, especially those close to the dam body and shoreline, were less suitable for FSPP siting due to shading and wave effects. Similarly, northern shallow zones were unsuitable due to increased wave height. The most suitable regions were located in the central and southeastern parts of the reservoir, where water is deeper, there are no surrounding islands, and distance from the shoreline minimizes disturbance. In conclusion, this thesis proposes and demonstrates a novel and replicable spatial methodology for determining suitable FSPP installation sites within a reservoir. The approach provides a systematic framework that can be adapted for other reservoirs worldwide. The study also offers practical guidance for future projects that aim to integrate renewable energy development with sustainable water resource management.
DR. MEHMET SEREN KORKMAZ
English 
Turkish