https://www.um.edu.mt/library/oar/handle/123456789/36288 2026-04-14T23:16:46Z 2026-04-14T23:16:46Z https://www.um.edu.mt/library/oar/handle/123456789/37502 2020-05-25T07:13:00Z 2018-01-01T00:00:00Z

Title: A study on the performance of solar photovoltaic modules exposed to salt water Abstract: The floating photovoltaic installation is a new concept which combines land-based PV technology with recently evolving floating system approach. A number of floating PV systems have been developed worldwide on various types of fresh water bodies. However, for countries like Malta, being in possession of marine territorial waters, one must take into account the potential effect of salt on the performance of solar modules, when implementing an offshore installation. While the effect of dust accumulation on PV panels is well-known, and is proven to significantly reduce their performance, even up to 50%, the consequence of salt build-up is still poorly understood. Since salt is not as opaque as dust, it is not clear how much it will shade or to what extent it would accumulate by repeated wetting of the panels. Salt water drying on solar panels, is one of the factors affecting floating PV performance, hence its impact was examined in this research. A sequence of tests were performed on monocrystalline modules which combined several factors that resulted in eight types of wetting treatments. The variations involved different salt solutions (seawater and saturated solution), inclination angles of photovoltaics (5° and 30°), as well as various types of wetting nozzles (fine mist and jet trigger sprayers). Auxiliary tests involved replicating the spraying procedure on glass sheets in order to check the level of opacity and percentage coverage of deposited salt layer. Moreover, tests were also conducted on microscope slides to examine light transmittance, thickness and morphology of salt crystals. To further analyse the impact of salt water on the performance of different PV technologies (polycrystalline silicon, amorphous silicon and CIGS modules), two types of setups have been constructed. One of the setups exposed the panels to a partial immersion and the other subjected them to the dripping procedure. Artificial deposition showed that seawater leads only to minimal traces of salt build-up that corroborates the findings of the earlier research, which revealed that shading from sea salt does not have such a pronounced effect. The surface of the glass samples treated with seawater, remained relatively translucent and thus a drop in the amount of light passing through the sample ranged only up to 3%. When it comes to the power output, the panels treated with seawater exhibited only a slight drop or no effect on the performance, and in some cases, improvements were also observed. However, based on the results of extended wetting with salt water, it was noted that the modules exposed to continuous contact with salt through immersion and water flow, suffered apparent losses in their performance. The percentage drop in power performance measured after a total of 30 days of immersion procedure ranged from around 14 to 28 %, depending on the PV technology. Whereas, the percentage reduction noted after completing a total of 30 days of dripping procedure varied from about 13 to 25 %, with the largest drop in the output exhibited by the CIGS panels. Therefore, it can be postulated that it is feasible to adapt the scenario of floating PV panels on the sea. Nevertheless, the key success of such venture is strictly linked to selection of adequate PV technologies and adoption of necessary measures to withstand the harsh marine conditions. The modules implemented at sea need to have a suitable protection from the water and/or be placed sufficiently high so that they will not often come in close contact with seawater. Description: M.SC.SUS.ENERGY

2018-01-01T00:00:00Z https://www.um.edu.mt/library/oar/handle/123456789/37494 2020-05-25T07:15:15Z 2018-01-01T00:00:00Z

Title: Enhancing sustainable energy education in secondary schools : a resource pack for educators Abstract: Education for Sustainable Development (ESD) is one of the six cross-curricula themes presented in the National Curriculum Framework of 2012. This should be achieved by active participation of all the stakeholders involved. However, there is lack of resource material for this subject with the result that every teacher tries to formulate his or her own notes. This could allow certain misconceptions to be relayed to students as absolute truths if educators are not properly trained in this subject. This dissertation aims at providing educational material that can be used by educators as a resource for sustainable energy education. The work is based on published scientific evidence that is mostly applicable to Malta as well as on the knowledge acquired during this M.Sc. study course. The innovation lies not only in the relevance to the Maltese context but also in the provision of user-friendly materials that can be easily adapted by the educators. This dissertation is divided into five major chapters. The first chapter gives a brief introduction to Education for Sustainable Development, its advantages, challenges, perception and its implementation. Chapter 2 focusses on the curriculum of Maltese schools and how educators and those in management position look at it. The content of the Resource Pack is found in Chapter 3. Chapter 4 gives an evaluation of the Resource Pack based on the reactions of educators and how the material helped the educators and their students. This led to a joined action where the educators and students suggested improvements in their school’s energy performance. Finally, Chapter 5 contains a summary and relevant recommendations for future work. The Resource Pack consists of eight lessons focused on the Physics theme “On the Move” and another two lessons focused on innovative, renewable energy technologies and systems. A CD with the relevant slides, videos and links required for each lesson and activity listed is accompanying the Resource Pack. The topics follow the syllabi provided by the Matriculation and Secondary Education Certificate SEC Syllabi of the year 2019. Description: M.SC.SUS.ENERGY

2018-01-01T00:00:00Z https://www.um.edu.mt/library/oar/handle/123456789/37490 2020-05-25T07:10:42Z 2018-01-01T00:00:00Z

Title: Optimizing ventilation in schools for improved comfort and energy efficiency Abstract: Thermal comfort (TC) and Indoor Air Quality (IAQ) in classrooms are critical for students to achieve their learning potential in a healthy environment. Ventilation to maintain IAQ is very energy intensive, so it is important that it is carried out in a sustainable manner. This study aims to identify whether the use of natural ventilation, as is the current practice in schools in Malta, is sufficient to satisfy EN 15251 TC and IAQ requirements. The study also aims to identify the best way mechanical ventilation can be applied to optimise IAQ, TC and energy efficiency. Temperature and carbon dioxide (CO2) data from a typical school building in Malta was used to calibrate an EnergyPlus building model. Results showed that for fully occupied classrooms having closed windows in winter, infiltration (alone) was not adequate to provide the required IAQ based on CO2 ppm readings. In contrast, CO2 levels can be controlled within safe limits when demand controlled mechanical exhaust ventilation is applied. This was confirmed via monitoring of CO2 ppm over a one-year period. The same exhaust fan also improved TC by bringing in pre heated corridor air in winter while reducing the temperatures by 1 ° to 1.4 °C during the summer via night purging. Computational Fluid Dynamics (CFD) confirmed that inlets placed close to floor level between classrooms and corridors provide the best IAQ at student working height while inlets placed on top provide the best TC. In addition, initial EnergyPlus analysis showed that continuously running exhaust fixed speed fans provide the lowest financial global costs over a 20-year period versus the more complex demand control ventilation scenarios. The study has primarily concluded that mechanical ventilation in schools is required to ensure IAQ and optimise TC, while also enabling energy savings in space heating and cooling. Description: M.SC.SUS.ENERGY

2018-01-01T00:00:00Z https://www.um.edu.mt/library/oar/handle/123456789/37487 2020-05-25T07:08:22Z 2018-01-01T00:00:00Z

Title: Modelling an energy storage system using brine Abstract: This dissertation focuses on the possible application of a viable energy storage/ recovery system for the Reverse Osmosis plants on the Maltese Islands, as an alternative to other proposals submitted in the past. An in-depth analysis on the production and energy consumption was done for each Reverse Osmosis plant for a twelve-year period. From this, several key points were highlighted that would affect the choosing of the system:  The system chosen must not negatively affect or halt the daily operation of the  Reverse Osmosis systems,  The system chosen must also not reduce the amount of potable water being  produced by the Reverse Osmosis systems,  The final setup must be compact and use as little space as possible,  It must be easy to install and maintain,  Be non-hazardous to the environment and the operators Through research, Reverse Electrodialysis was chosen for further analysis. This consisted of the comparison of the potential energy, using the published method for this system and a set of equations. Following this, a series of tests were done using models from literature and comparison of results to confirm the potential of this system for the chosen scenario. From this analysis and comparison, mixed results were achieved with the greatest highlight being that the power densities exceeding the literature benchmark value of 6.04 W/m2 [1]. Finally, a scale-up experiment and payback period was done, including testing the potential of using multiple systems in series or parallel to each other. From this final analysis, due to the high costs of the materials used, the best payback achieved was that of ten years at the fixed rate of €0.08c/kWh. Description: M.SC.SUS.ENERGY

2018-01-01T00:00:00Z