Sayedus Salehin

Energy Efficient Hybrid Dual Axis Solar Tracking System

This paper describes the design and implementation of an energy efficient solar tracking system from a normal mechanical single axis to a hybrid dual axis. For optimizing the solar tracking mechanism electromechanical systems were evolved through implementation of different evolutional algorithms and methodologies. To present the tracker, a hybrid dual-axis solar tracking system is designed, built, and tested based on both the solar map and light sensor based continuous tracking mechanism. These light sensors also compare the darkness and cloudy and sunny conditions assisting daily tracking. The designed tracker can track sun’s apparent position at different months and seasons; thereby the electrical controlling device requires a real time clock device for guiding the tracking system in seeking solar position for the seasonal motion. So the combination of both of these tracking mechanisms made the designed tracker a hybrid one. The power gain and system power consumption are compared with a static and continuous dual axis solar tracking system. It is found that power gain of hybrid dual axis solar tracking system is almost equal to continuous dual axis solar tracking system, whereas the power saved in system operation by the hybrid tracker is 44.44% compared to the continuous tracking system.

Application of Nanofluid in Heat Exchangers for Energy Savings

Nanotechnology is a promising field in sustainable energy to reduce the energy consumption for optimum design of heat exchangers. Nanofluid provides significant improvement of thermo-physical properties and augmentation of heat transfer coefficients as well as reduces the pumping power if properly selected. In this chapter a CFD simulation using a finite volume method is presented for investigation of the hydrodynamic and thermal behavior of nanofluid flowing through a circular tube of heat exchanger with constant heat flux under single-phase turbulent flow condition for Reynolds number from 4000 to 20,000. Three different nanoparticles (Al2O3, CuO, and TiO2) with different volume fractions (1–5%) dispersed in water are analyzed. The heat transfer coefficient and pumping power increase with the increase in both the Reynolds number and volume fraction. The maximum saving of pumping power at a particular heat transfer coefficient has been obtained at 2% volume fraction for Al2O3–water and TiO2–water nanofluid and at 3% volume fraction for CuO–water nanofluid.

Utilization of Nanofluid in Various Clean Energy and Energy Efficiency Applications

Policy makers around the globe, both at the national and international level, have been emphasizing on energy efficiency and utilization of alternative clean energy technologies by replacing fossil fuel as a primary source of energy. This interest was initiated when the adverse effects of fossil fuel on the environment such as greenhouse gas emission and global warming were unfolded. Multidisciplinary researches are being carried out in the research laboratories to provide effective clean energy solutions. Nanofluid, a colloidal mixture of nanoparticles in the base fluid, e.g., water, ethylene glycol, oil, offers efficiency improvements in many clean energy applications due to the improvement in its thermophysical property. In this chapter, use of nanofluid in various clean energy and energy efficiency applications is reviewed. Solar energy, the dominant clean energy source, is a potential field of application where nanofluid can be employed. Solar thermal collectors and solar water heaters are the ideal candidates for utilization of nanofluid for improving solar to thermal energy conversion. Thermal storage system employs phase change material (PCM) for storing thermal energy, and nanofluid may be added to the PCM for enhanced performance. Nanofluid can be used in carefully designed heat exchangers for extracting energy from geothermal resources. This mixture can also be used in waste heat collector to improve efficiency for its thermophysical property causing a heat transfer enhancement. Adding nanoparticles to the refrigerants improves the heat transfer characteristics of refrigerants and improves the performance of the refrigeration system from an energy efficiency perspective. However, there are challenges associated with nanofluid which are needed to overcome for optimal performance of the working fluid.

Economic and environmental assessments of solar home systems consisting different lighting sources

In Bangladesh, 55% of the population are getting electricity from the national grid. Mostly diesel generators supply the electricity to the off-grid regions. Use of diesel leads to increased greenhouse gas (GHG) emissions which is a big environmental concern all over the world. Solar Home Systems (SHSs) offer promising solution to the areas that are not connected to the grid. More than 3.6 million SHSs are installed in remote locations across the country. Most SHSs in Bangladesh use small tube lights as the lighting source. However, the recent SHSs make use of LED bulbs instead of the tube lights in order to decrease the PV panel size which would lower the initial capital cost and annualized cost. In this study, two different Solar Home Systems were analysed having tube lights and LED bulbs as the lighting source, respectively. Each of the SHSs consists of 6 lights (Tube light/LED bulb) and 2 fans with operating hours of 4 daily. The analysis shows that the SHS with tube lights requires initial capital cost of

Environmental Impact Assessment of Different Renewable Energy Resources: A Recent Development

432, which is 48% higher than the system having LED bulbs as the lighting source. As the SHSs do not use any fossil fuel, there is no operational GHG emission. However, a large amount of energy is used to manufacture PV panels, which needs to be quantified to understand the environmental impact. Energy consumption to manufacture the solar panels of Solar Home System with LED bulbs is 1.44 MWht which is 25% lower than the SHS with tube lights.

Economic challenges of hybrid microgrid: An analysis and approaches for rural electrification

Abstract For a sustainable development of human civilization, a secure and sufficient energy supply is very crucial. Global energy demand is expected to grow substantially, which will lead to increased production of energy from various sources. Conventional energy sources (e.g., oil, coal, and natural gas) drive economic progress, but utilization of these sources produces significant amounts of greenhouse gases that are responsible for global warming and ozone layer depletion. Policy regulations, such as Californias low carbon fuel standard and European Unions fuel quality directive, encourage energy generation from cleaner sources. Renewable energy sources (e.g., solar, wind, biomass, hydro, and geothermal) are cleaner and easily accessible compared to conventional sources of energy. The potential of renewable energy sources is enormous. Renewable energy sector is growing faster and providing sustainable energy services. In this chapter, environmental impact assessments of different renewable energy generation systems are reviewed.

Modeling of an Optimized Hybrid Energy System for Kutubdia Island, Bangladesh

This paper focuses on the integration of three renewable resources: biogas, wind energy and solar energy, utilizing solar PV panels, a biogas generator, and a wind turbine, respectively, to analyze the technical and economic challenges of a hybrid micro-gird. The integration of these sources has been analyzed and optimized based on realistic data for a real location. Different combinations of these sources have been analyzed to find out the optimized combination based on the efficiency and the minimum cost of electricity (COE). Wind and solar energy are considered as the primary sources of power generation during off-peak hours, and any excess power is used to charge a battery bank. During peak hours, biogas generators produce power to support the additional demand. A business strategy to implement the integrated optimized system in rural areas is discussed.

Study of Turbulent Convective Heat Transfer Enhancement by Al2O3-Water Nanofluid through a Rough Circular Tube

This paper presents an optimized energy system model for a small locality in Kutubdia Island, Bangladesh at latitude of 21.82 °N, longitude of 91.86 °E. This isolated island is located at the southern coast of Bangladesh, separated from the main land by the Kutubdia channel. At present, grid connection from the mainland is not present and is not planned in the near future. The proposed energy system comprises Solar PV, Wind turbines, Biogas generators for power generation whereas a diesel generator has been used as backup power supply and batteries have been considered to facilitate energy storage. Hybrid Optimization Model for Electric Renewable (HOMER) has been used to obtain an optimized system comprising all the renewable energy resources present. The designed energy system consists of 28 kW Solar PV panels, 30 kW Wind Turbines, 8 kW Biogas Generator, 9 kW Diesel Generator. The system generates electricity with a renewable fraction of 97%. The cost of electricity has been estimated as US

Reduction of cooking energy and CO2 emission using heat retention cooker for rice cooking

0.42/kWh considering 10% Rate of Return with an initial capital cost of US

From strain to extraction — A review to produce biodiesel from microalgae in Bangladesh

199,541.