Scope of Concentrated Solar Power Technology in Pakistan

Concentrating solar power plants produce electric power by converting the sun's energy into high-temperature heat using various mirror configurations. The heat is then channelled through a conventional generator. The plants consist of two parts: one that collects solar energy and converts it to heat, and another that converts heat energy to electricity. This is combinely called solar thermal electric power plant. Concentrating solar power (CSP) technologies, including parabolic troughs, power towers, and dish/engines, have the potential to provide the world with tens of thousands of megawatts of clean, renewable, cost-competitive power beginning later this decade. These technologies can be used to generate electricity for a variety of applications, ranging from remote power systems as small as a few kilowatts (kW) up to grid-connected applications of 200-350 megawatts (MW) or more. A concentrating solar power system that produces 350 MW of electricity displaces the energy equivalent of 2.3 million barrels of oil. Developing countries in Asia, Africa, and Latin America—where half the populations currently without electricity and sunlight is usually abundant—represent the biggest and fastest growing market for power producing technologies. A number of projects are being developed in India, Egypt, Morocco, and Mexico. The benefits from CSP technology from economical point of view is it reduce consumption of fossil fuels, from environmental point of view it reduces air pollutants or greenhouse gas emissions and it produces clean power. CSP technology is ideally suited for multi-megawatt central power plants. It is a proven technology with 354 MW operating successfully in California for the past 25 years. And rapidly deployed because it uses conventional items such as glass, steel, gears, turbines, etc

Thermal Conductivity Measurement of Vacuum Tight Dual- Edge Seal for the Thermal Performance Analysis of Triple Vacuum Glazing

A vacuum tight glass edge seal’s thermal conductivity is one of the principal factor in determining the heat distribution towards the centre of pane, ultimately influences the thermal transmittance (U-value) of a triple vacuum glazing. So far indium and solder glass have proven to be vacuum tight edge sealing materials but both have certain limitations. In this chapter, a new low-temperature vacuum tight glass edge seal composite’s thermal conductivity, Cerasolzer CS186 alloy and J-B Weld epoxy-steel resin, were measured and validated with the mild-steel and indium using transient plane source method with a sensor element of double spiral and resistance thermometer in a hot disk thermal constants analyser TPS2500s are reported. The thermal conductivity data of Cerasolzer CS186 alloy and J-B Weld epoxy steel resin were measured to be 46.49 and 7.47 Wm−1 K−1, with the deviations (using analytical method) of ±4 and ±7% respectively. These values were utilised to predict the thermal transmittance value of triple vacuum glazing using 3D finite element model. The simulated results show the centre-of-glass and total U-value of 300 × 300 mm triple vacuum glazing to be 0.33 and 1.05 Wm−2 K−1, respectively. The influence of such a wide edge seal on the temperature loss spreading from the edge to the central glazing area is analysed, in which the predictions show wider edge seal has affected the centre-of-glass U-value to 0.043 Wm−2 K−1 due to the temperature gradient loss spread to 54 and 84 mm on the cold and warm side respectively

Vacuum Insulation and Smart Coatings for Net Zero Energy Buildings: Current Status and Future Prospects

The perception at which, nowadays, net zero energy buildings (NZEBs) cannot be imagined without glass is because glazed windows play an imperious role of allowing natural daylighting, but with repercussion of space-heating energy loss in cold-arid and space-cooling energy loss in hot-arid areas. As such, evitable energy losses through glazed windows of NZEBs indirectly contributing to carbon emissions and, thus, impelling climate change. This is, predominantly, due to an inadequate thermal transmittance value (U-value) of a glazing and not use of progressive coating technologies. This talk aims to present the novel constructions and performance characteristics of the advanced smart vacuum insulation technologies with semi-transparent photovoltaic and electrochromic coatings for NZEBs that are: (i) Vacuum Glazing (VG), (ii) Triple Vacuum Glazing (TVG), (iii) Electrochromic Vacuum Glazing (EVG), (iv) Semi-transparent Photovoltaic Electrochromic Vacuum Quadruple Glazing (STPV-EVG), (v) Translucent Vacuum Insulation Panel (TVIP), and (vi) Fusion-sealed Vacuum Glazing (FVG). The experimental results show VG achieved U-value of 0.97 Wm-2K-1, it was further reduced with TVG that achieved U-value of 0.33 Wm-2K-1. To control the solar heat gains from 0.41 (transparent mode) to 0.13 (opaque mode), ECG is constructed that achieved U-value of 0.82 Wm-2K-1, it required electrical power of < 0.4 Wm-2. To make it self-reliant, the semi-transparent PV glazing was integrated to EVG to supply the power and store the generated energy using NiMH battery, the STPV-EVG achieved U-value of 0.79 Wm-2K-1. Due to the cost of hermetic glass edge-sealing materials, a new structured core transparent vacuum insulation panel (TVIP) is constructed, to accomplish insulation for the windows without edge sealing effects, that achieved U-value of 1.72 Wm-2K-1 but longevity of vacuum pressure is a challenge. The development of novel cost-effective fusion seal for the construction of fusion-sealed vacuum glazing (FVG) that achieved hermetic airtight vacuum seal with the U-value of 1.24 Wm-2K-1 is seemed to be the most low-cost solution for mass production

Introductory Chapter: Introduction to Advanced Thermoelectric Materials for Energy Harvesting Applications

Advanced Thermoelectric Materials for Energy Harvesting Applications is a research-intensive textbook covering the fundamentals of thermoelectricity and the process of converting heat energy into electrical energy. It covers the design, implementation, and performance of existing and advanced thermoelectric materials. Chapters examine such topics as organic/inorganic thermoelectric materials, performance and behaviors of thermoelectric devices, and energy harvesting applications of thermoelectric devices

Advanced Thermoelectric Materials for Energy Harvesting Applications

Electrical energy consumption is negatively affecting our environment and contributing to climate change. Therefore the research and industrial communities are working hard to minimize energy consumption using promising energy-efficient and renewable energy technologies. We know that it is possible to convert heat energy into electrical energy using thermoelectric devices; this heat energy can be from the sun or from an electro-mechanical device. However, thermoelectric devices traditionally suffer from lower efficiencies of energy conversion. This book, Advanced Thermoelectric Materials for Energy Harvesting Applications, is a researchintensive textbook consisting of eight chapters organized into three sections. Section 1 consists of Chapters 2, 3, and 4, which cover advanced thermoelectric materials and the topics of organic/inorganic thermoelectric materials, quantum theory of the Seebeck coefficient for the advancement of thermoelectric superconducting material, and the limits of Bismuth Telluride-based thermoelectric materials. Section 2, containing Chapters 5 and 6, evaluates behaviors and performance of thermoelectric devices. Section 3, containing Chapters 7 and 8, focuses on energy harvesting applications of thermoelectric devices. This book will be of interest to a wide range of individuals, such as scientists, engineers, researchers, and undergraduate and postgraduate students in the field of advanced thermoelectric materials

Smart Vacuum Glazing invented with Energy-Efficient Fusion Seal for the Solar Thermal Transmittance Control in Buildings

Carbon footprint and energy efficiency of buildings are deemed to be the global concerns due to links with fuel poverty and climate change. There is also a solemn prospect of balancing the energy supply and energy demand. Smart vacuum glazing is a quintessential development in the move to energy-efficient buildings because of the solar thermal energy loss through conventional windows (such as double or triple glazed windows) in the cold-arid countries such as Russia, EU and UK. The reason vacuum glazing is smart is as it maintains the transparency, regardless of tiny pillar dots ( 0.13 mm high and 0.3 mm wide made of stainless steel allow), and its slim due its narrow vacuum gap (0.13 mm height) when compared to the conventional glazing. A vacuum gap essentially is a space, between two glass sheets, of reduced mass of atmospheric-air, thus air-density defines the level of the vacuum pressure. This provides solar thermal vacuum insulation, because with a lower density of air the mean free path between air molecules can be increased to above 1000 m, ultimately reduces the solar thermal flow between air molecules in a space. The space between two glass sheets is usually evacuated to high-vacuum pressure (0.13 Pa to 1.33·10-4 Pa) in order to reduce conductive and convective thermal transmittance to marginal levels, however the solar energy transmittance through radiation can only be minimized using low-emittance coatings. In this paper the results of the experimental and theoretical investigations into the development of lead-free and ultrasonic soldering free fusion seal made of B2O3 surface textured layer and ultrasonically soldered with Sn90In10 alloy wire sealing the edges of the two glass sheets hermetically (named fusion seal) are reported. The glass sheets are separated by 0.13mm high and 0.3 mm diameter support pillars. A medium-vacuum pressure of the evacuated cavity between two glass sheets is achieved to be 0.095 Pa. Stress patterns were observed during the evacuation and the pump-out hole was sealed with improved method and composite, Cerasolzer-CS186 alloy. A three-dimensional finite-element model for this prototype was also developed. It was implemented on predicting the centre-of-glass thermal transmittance of fusion-sealed vacuum insulated glazing to be 1.039 Wm-2K-1, which is about five times less than the thermal transmittance of the conventional single glazing. The results show that the fusion seal is potentially a most cost-effective solution as compared to other sealing materials

An a posteriori error analysis of a mixed finite element Galerkin approximation to second order linear parabolic problems

In this article, a posteriori error estimates are derived for a mixed finite element Galerkin approximation to second order linear parabolic initial and boundary value problems. Using mixed elliptic reconstruction method, a posteriori error estimates in $L^\infty(L^2)$ and $L^2(L^2)$-norms with optimal order of convergence for the solution as well as its flux are proved for the semidiscrete scheme. Finally, based on backward Euler method, a completely discrete scheme is analyzed and a posteriori bounds are derived, which improves earlier results on a posteriori estimates for mixed parabolic problems

Why physicians and lay people smoke and how can it be reduced?

Objective: The objective of this study was to find out the level of knowledge the physicians and lay people have pertaining to the effect of cigarettes, why certain physicians smoke and what measures could be applied to reduce the rate of smoking. Methods: A questionnaire was administered to the one hundred physicians who smoke, one hundred non-smoking physicians and one hundred lay people who smoke to determine their attitude towards this addition. Subjects were chosen using convenience sampling. The physicians were picked from six hospitals of Karachi. Results: When the smoking physicians were asked what could motivate them to stop smoking, majority of them said that an occurrence of a smoking related illness would. Majority of the physicians who do not smoke felt that individual will was the greatest force keeping them from smoking. When asked how smoking can be reduced in Pakistan, majority of the physicians, both smoking and non-smoking, favoured mass health education. Lay smokers expressed marked ignorance about deleterious effects of cigarette smoke. Like smoking physicians, majority of them said that occurrence of an illness related to smoking would effectively motivate them to stop smoking. CONCLUSION: Based on this survey we conclude that mass health education and enforcement of the ban on smoking in public places will effectively reduce the number of smokers. There is a need to educate physicians and the general public about the cardiac and carcinogenic effects of smoking

Effect of hot-arid climatic solar energy on monocrystallinephotovoltaic performance in Pakistan

The domestic dwellings in Pakistan have predominantly implemented low-carbon strategies by harvesting solar energy using photo-voltaic (PV) panels as a long-term vision of low-carbon economy. Most of the urban areas in Pakistan stay hot and humid in an entire year. Consistent solar irradiation at higher temperatures is one of the major factors that affect the power generation performance of monocrystalline PV systems pose challenges to performance and degradation issues. Monocrystalline PV module efficiencies are declining and damaging under the continuous exposure to higher surface day-time temperatures in the different parts of the country. MATLAB simulations were performed based on the validated mathematical approach. This paper investigates the hot arid surface temperature impacts on the performance of PV modules during the summer and winter seasons in Pakistan. The investigations are performed examining the comparative output power generating performance of the PV system. This paper also investigates the influence of installations of PV-system in the North, South, East and West regions of Pakistan. It was examined that the northern areas of Pakistan are more suitable for maintaining the long-term durability of the PV system. Investigations are performed for the peak summer and peak winter days. During summer months, cooling strategies have to be implemented to overcome the heating effects whilst reducing degradation effect on installed PV-system

MODLEACH: A Variant of LEACH for WSNs

Wireless sensor networks are appearing as an emerging need for mankind. Though, Such networks are still in research phase however, they have high potential to be applied in almost every field of life. Lots of research is done and a lot more is awaiting to be standardized. In this work, cluster based routing in wireless sensor networks is studied precisely. Further, we modify one of the most prominent wireless sensor network's routing protocol "LEACH" as modified LEACH (MODLEACH) by introducing \emph{efficient cluster head replacement scheme} and \emph{dual transmitting power levels}. Our modified LEACH, in comparison with LEACH out performs it using metrics of cluster head formation, through put and network life. Afterwards, hard and soft thresholds are implemented on modified LEACH (MODLEACH) that boast the performance even more. Finally a brief performance analysis of LEACH, Modified LEACH (MODLEACH), MODLEACH with hard threshold (MODLEACHHT) and MODLEACH with soft threshold (MODLEACHST) is undertaken considering metrics of throughput, network life and cluster head replacements.Comment: IEEE 8th International Conference on Broadband and Wireless Computing, Communication and Applications (BWCCA'13), Compiegne, Franc