http://repository.ou.ac.lk/handle/94ousl/3643 2026-05-16T00:54:10Z http://repository.ou.ac.lk/handle/94ousl/3805 FORECASTING SOLAR ELECTRICITY GENERATION POTENTIAL ON 18 MAJOR RESERVOIR SURFACES IN SRI LANKA USING LONG SHORT-TERM MEMORY (LSTM) MODEL Premathilaka, S.D.A.V.S.; Yapa, R.D.; Punchi-Manage, R. Sri Lanka’s energy sector remains heavily reliant on fossil fuels, with coal and oil generating about 50% of total electricity as of 2023. Despite significant solar irradiance potential, solar energy contributes just 5% to the national grid. A major constraint to large-scale solar expansion is land-use conflict with agriculture, urban development, and ecological conservation. Floating Solar Photovoltaic (FPV) systems, deployed on reservoir surfaces, offer a sustainable alternative by utilizing underutilized water bodies without competing for land. This study focuses on forecasting the monthly solar energy potential across 18 major reservoirs in Sri Lanka, considering a 1 m² panel area for each site, using a Long Short-Term Memory (LSTM) model. The results of this study will help assess the feasibility of deploying FPV systems. Solar energy generation potential was derived by adjusting measured irradiance for environmental factors such as cloud cover, precipitation, atmospheric pressure, and surface reflectivity, combined with panel efficiency based on a 1 m² panel area. A separate LSTM model was trained for each site using a 12-month input sequence to predict the subsequent month’s solar energy output. Data were standardized and split into training (80%) and testing (20%) subsets. Each model incorporated dropout and early stopping to mitigate overfitting, and performance was evaluated using Root Mean Squared Error (RMSE), Mean Absolute Error (MAE), and Mean Absolute Percentage Error (MAPE). Historical data revealed strong seasonality, with average daily outputs ranging from 1–4 kWh/m², and peaks exceeding 5 kWh/m² in certain months. February to April were generally the most productive months. RMSE ranged from 0.64 to 0.89, with MAPE values below 0.57, indicating relatively accurate forecasts. Site-specific variability influenced model performance. Future studies could explore integrating climate change projections and reservoir-specific operational data to improve long-term forecasting accuracy and support strategic planning for FPV system deployment. 2025-01-01T00:00:00Z http://repository.ou.ac.lk/handle/94ousl/3802 FEASIBILITY STUDY OF MICRO-SCALE WIND POWER GENERATION FOR RURAL ELECTRIFICATION IN POLONNARUWA AREA Samaraweera, S.P.P.; Sasikala, R.H.G. Wind energy is one of the most promising alternative renewable energy technologies at present to sustain the increasing energy demand, whereas fossil fuels have negative effects on the environment. Moreover, the fossil is directly related to air pollution, land and water degradation. Despite significant progress made in power generation using large-scale wind turbines recently, domestic-scale wind turbines have received less attention, which have immense potential for standalone power generation. In this paper, micro-scale wind power generation in the Polonnaruwa area was investigated. The technical and economic feasibility of tower-mounted micro-scale standalone wind turbine installation was conducted. The potential of micro-scale wind power generation was statistically analyzed. The average wind speed data of a three-seasonal intervals of two years (2019 and 2020) was collected and analyzed to find the potential of wind power generation in the specified area. The Weibull probability distribution was applied to calculate the wind speed distribution at different heights. Therefore, the annual wind power potential of the area and the energy production of the selected wind turbine were estimated. Study results show that installation of the wind turbine at 10m hub height for this particular area gave better performance of annual energy production, capacity factor and, carbon savings. Therefore, a 500 W turbine with low cut- in wind speed of 2 m/s, was selected as the most appropriate micro scale wind turbine which can be installed at the site under study. 2025-01-01T00:00:00Z http://repository.ou.ac.lk/handle/94ousl/3799 CRITICAL REVIEW OF GREEN RATING SYSTEMS IN BUILDING - INTEGRATED VEGETATION AND APPLICATION CHALLENGES IN SRI LANKA Ekanayaka, M.; Senalankadhikara, A.; Chathurika, S. Today’s world faces many burdensome issues, such as climate change, biodiversity loss, resource depletion, urbanization, and food insecurity. There is a growing attention to circularity and sustainable development. In this context, sustainable built environments that promote nature's regeneration play a vital role in leading to numerous benefits for overpopulated urban environments. Several studies have explored different types of Building Integrated Vegetation Systems (BIVSs) and their benefits, as well as the challenges/barriers to adopting them in both the Global and Sri Lankan contexts. However, very few studies have focused on the role of vegetation in Green Rating Systems. This study categorizes the literature on different types of BIVSs, their role in Green Rating Systems (GRSs), common implementation and maintenance challenges, and the main barriers to adopting in the Sri Lankan context. The main objective of the study is to investigate the main reason why many green-certified buildings achieve the certification without integrating vegetation systems, specifically in the Sri Lankan scenario. This study is based on a critical review of 26 scholarly publications from relevant journals and online scientific databases. According to the findings, most Green Rating Systems do not offer direct points for incorporating vegetation systems into green buildings. Instead, points can be achieved through the benefits these systems offer. Those benefits can be achieved by other alternative sustainable practices. This has resulted in buildings obtaining the green certification without integrating any BIVSs. Furthermore, the study identifies the cost as the main barrier to adopting BIVSs in the Sri Lankan context, which is associated with their installation and maintenance. 2025-01-01T00:00:00Z http://repository.ou.ac.lk/handle/94ousl/3797 EVALUATING THE EFFECTIVENESS OF USING DREDGING MATERIAL FROM OLIYAMULLA RETENTION POND AS A LANDFILLING MATERIAL IN COLOMBO, SRI LANKA Watson, T.H.; Denagama, T.D. The Sri Lanka Land Development Corporation (SLLDC) has developed the Oliyamulla Storm Water Drainage & Environment Improvement Project, aiming to control flooding in enhance the physical properties of dredged soil for landfilling. While the dredged soil is chemically acceptable, it lacks desirable natural physical properties for direct the Wattala, Peliyagoda, Kelaniya, Wanawasala, and Kiribathgoda areas by dredging the Oliyamulla retention pond. However, the project faces challenges in space, storage, and disposal. This study observes quarry dust as a cost-effective, eco-friendly substitute for stabilization of soil in landfilling, which is an answer to the prohibitive cost of cement in environmental operations. And assesses the environmental value of dredged material as a disposal site for wastes and demonstrates it to be pH neutral, of low electroconductivity, chlorides, organic matter, minimal heavy metals, and free from harmful toxins. Also, the use of quarry dust as a low-cost and environmentally friendly stabilizing agent for weak and soft soils. Laboratory tests for particle size distribution, Atterberg's limits, and proctor compaction on Oliyamulla retention pond dredged soil showed that mixing quarry dust with soil showed good soil improvement with acceptable landfilling limits. The cost breakdown also established that quarry dust usage is economical compared to other methods of disposal, thus making it an efficient and environmentally friendly method of ground improvement. And research evaluates the feasibility of using quarry dust to use without treatment. Experimental findings show that a 40% quarry dust and 60% dredged soil mixture enhances some significant physical properties like density, particle size distribution, and plasticity index significantly in favour of landfilling. 2025-01-01T00:00:00Z