No abstract

Off-grid Photovoltaic (PV) system along with battery storage is very effective solution for electrification in remote areas. However, battery capacity selection is the most challenging task in system designing. In this study, an off-grid PV system along with battery storage is designed for the remote area of Karachi, Pakistan. The system is designed by considering the maximum energy requirement in summer season. The battery storage is selected to fulfill the energy demand during the night and cloudy seasons. On the basis of load, a total of 6 kW system is required to fulfill the energy demand. For such system, 925 Ah of battery is required to meet the energy requirement for a day in absence of solar irradiation. A regression-based correlation between battery capacity and energy demand is prepared for suitable battery sizing using Minitab. An economic analysis of the project is also carried out from which a net present value and simple payback are determined as USD 10,348 and 3 years, respectively. The environmental benefits are also been determined. It is found that the system will reduce around 7.32 tons of CO2 per annum which corresponds to the 183.69 tons of CO2 not produced in the entire project life.

Water, a basic human need can be purified by different techniques like membrane distillation, boiling and solar still. Among all types, solar still is considered to be the most economical and simpler one. In this study, the geometrical aspects of the solar still for Karachi by varying the tilt has been simulated. The study is conducted by varying the height and length of the solar still by keeping the constant glass surface area and by varying the height and length of the glass cover while keeping the constant basin area. The study is conducted between the time duration from 08:00 to 18:00 hours which is generally the sunshine duration for Karachi. The simulation results are verified with the experimental results which shows the good agreement with each other. For constant glass cover area, the maximum mass production of water has been observed at a tilt of 60° while for constant basin area the maximum tilt is observed for 24.8° equal to the latitude of Karachi. For both the cases, the maximum temperature of water and glass and maximum mass production of water is observed at around 13:00 hours.

In developing countries such as Pakistan, the issue of generating power is crucial. As conventional power sources (fossil fuels) are depleting at an alarming rate. An abundant amount of energy is generated by thermal power plants using fossil fuels as their primary energy resource for combustion. Hence extreme uses of fossil fuels are noticed, which is greatly responsible for damaging our environment. Oceans exists around 71% of the surface area of earth and it has enormous potential for electricity generation. This study focuses on site selection for harnessing ocean energy by utilizing Ocean Thermal Energy Conversion (OTEC) systems for coastal areas of Pakistan. In this study, four sites across the coastal region of Pakistan have been studied namely Karachi, Gwadar, Ormara and Pasni. Their theoretical maximum Carnot efficiencies have also been determined and Gwadar has been identified as the most suitable location for OTEC plant with the maximum theoretical efficiency of around 6.53%, 6.93% and 7.75% at the cold-water depths of 1000m, 1200m and 1500m, respectively.

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