Appropriate decision making in energy technology selection for developing countries: The Life Cycle Assessment approach

As the high demand of energy of the developing countries is met by importing energy and different energy technology, it has become increasingly necessary to discuss the environmental impacts throughout the life cycle of those technologies and make better decisions. Developed in the late 1960s, Life Cycle Assessment (LCA) has become a wide-ranging tool used to determine impacts of products or systems over several environmental and resource issues. The LCA approach has become more prevalent in research, industry and policy with growing concern for the environment. Therefore, the aim of this paper is to introduce the use of LCA in the decision-making process while selecting an energy technology. In this way, more environmentally conscious decisions will be made as LCAs can provide a better basis for this process.

Fault Analysis of Solar Thermal Systems in Bhutan

The Royal Government of Bhutan has accorded the highest priority towards diversifying the energy-mix through the promotion of renewable energy technologies. There is a national target to generate 3 MW equivalent of energy from the installation of solar thermal systems alone. However, little investment and priority are given for development of solar thermal applications. Some of the present existing solar water heating (SWH) systems are exhibiting faults which leads to low consumer confidence in SWH technology due to the non-functioning of previous installations which is very detrimental in this introductory stage. This study aims to identify problems of existing SWH systems through field surveys and develop a draft guideline to avoid faults in the future. To analyse the problems with existing SWH systems in Bhutan, the first phase of the study consists of collecting secondary information and opinion from the relevant government sector, local installing companies and end-users. The information on the manufacturer’s products, policy barriers, markets and consumer challenges is also collected. Base on this information, findings on the limitation of existing policy instrument and gap in demand and supply side is described. The second phase of the study comprises field visits to existing SWH system sites. The field surveys of twelve representative existing SWH systems are analyzed. Out of twelve sites, eight SWH systems had critical faults which causes major failure of the system and the other four sites had minor faults. To analyse the faults of existing SWH systems, faults are classified into design faults, plumbing circuit faults, solar collector faults, absorber faults, installation faults and user behavior faults. The major faults which lead to the failure of the existing SWH system are plumbing failure, condensation inside the collector and absorber tube leakage. The causes and solutions of the faults are discussed.

Energy efficiency implementation and Greenhouse gas (GHG) reduction by replacing air conditioners by hot water absorption chiller

Climate change impacts are burning issues now-a-days all over the world. GHG emissions are mostly due to fossil fuel burning and inefficient energy use. Energy inefficiencies occurred by use of conventional energy technologies. The textile industries are one of the major manufacturing sectors in Bangladesh and energy consumption is quite high for energy production in this sector. Due to high energy demand, most of the textile industries use non-renewable energy source like natural gas, diesel and furnace oil for energy production. This high energy demand increases high consumption of fossil fuels & accelerating emission of GHGs. So, for future sustainability, energy efficiency is must to reduce GHGs and lowering the quantity of natural gas use for energy production. Moreover, purchased electricity consumption from national grid is also increasing every year. This report shows energy efficiency incorporation by using low energy consuming technologies for HVAC systems where co-generation is used i.e. using generator exhausts or hot cooling water (as a source of heat) for making cool water and use it for air cooling which will reduce dependency on air conditioners enhancing GHGs emission reduction. This will reduce the quantity of high Global warming potential refrigerants (R-22, R-134a and R407c) used in air conditioners. No extra heat source will be required in my process design & reuse the hot water as heat source for air cooling cycle. Financial feasibility also has done which will ensure economic profitability in parallel to Energy savings & GHG reduction. This study reveals that it is possible to reduce natural gas & refrigerant’s consumption which is responsible for GHG emissions.

A multivariate risk assessment of the airborne transmission of SARS-Cov-2 in different scenarios in Bangladesh: Identifying potential danger zones and proposing solutions

Bangladesh is a developing country with one of the world’s densest populations, and thus, is very vulnerable to the impacts of the COVID-19 pandemic. Bangladesh has found it challenging to contain the transmission of SARS-CoV-2, leading to a high number of COVID-19 cases. The dominant avenue of SARS-CoV-2 transmission is through airborne droplets. We have attempted to compare the probability of SARS-CoV-2 transmission in different scenarios and situations, with a view to proposing mitigations to reduce this risk in the context of the country. A multivariate approach was taken, whereby a number of physical and environmental parameters were considered. Based on the Wells-Riley model, we have integrated several different equations into the original, developing a modified model that takes into account the factors of distancing, ventilation and the decay of airborne particles. The modified model was run on a number of different scenarios and situations. From the results, a distance risk matrix was developed, which indicates the relative risk of transmission someone faces at a distance from an infectious person compared to the risk being at some other distance. Additionally, it was found that environments with strong sunlight exposure and high temperature and humidity have greatly reduced transmission risk, as the airborne deactivation of virus particles is accelerated. Proper ventilation in indoor situations also greatly reduces this risk. The results of the study are used to suggest a number of mitigation methods that can be adapted as policy or guidelines.

Shading devices applied to sun control in occupied spaces in summer conditions

This work presents a study of a numerical building dynamic simulation in the development of a horizontal shading device passive solution applied in a university canteen. The used building dynamic simulation software, that simulates simultaneously a building or groups of buildings with complex topologies, in transient conditions, considers the solar radiation, the HVAC system, glass radiative proprieties, radiative heat exchanges, thermal solutions, thermal comfort of occupants, indoor air quality, among others properties. The development of efficient external horizontal shading devices is made by a numerical model that uses the sun's trajectory and its position in relation to the windows where it falls. The canteen is constituted by three levels and is divided in 37 spaces. In the numerical simulation, 100 transparent surfaces and 773 opaque surfaces are considered. Special attention is given in the students’ main canteen, professors’ main canteen, specialized canteen and university bar. The simulation is made, in summer conditions, considered the selected spaces without and with horizontal shading devices placed above their windows. In the simulation, the occupancy and the implemented ventilation system are considered. Regarding to the obtained results the use of horizontal shading devices can reduce the air temperature range and improve the thermal comfort level that the occupants are subjected in some of the analyzed spaces.

Old town, Leh: Waste Management and Ecology

In this paper a research review is conducted considering the waste generated in the Old town area which lies in Leh, the capital city of Ladakh. If we trace back from 60’s era, Ladakh was a region where waste generation was negligible but as the time passes and improvement in infrastructure like road networks, army/military area development, increased influx of tourism, change in economy patter of Ladakhi families, lifestyle and way of living along with rapid growth of consumer goods, it experience changes for which the region was not prepared for. Due to this rapid urbanization mass production of waste started which started causing environmental misbalance. These waste are of various categories like, solid, toxic, chemical. Bio etc. Since waste was never considered as issue, less importance was given to it and thus when generation of waste increases, Leh lack in its management. Most of the waste was dumped in the area which was outside the habitable land mainly valley. Thus in the paper an attempt has been made to identify waste typology and how it can be reuse or renewed which can help in preservation of the existing ecology and environment. Also various measures and method adopted by the local authorities will be studied.

Developing low-cost methane gas concentration measuring device

In every aspect of Engineering more advanced, efficient and progressive solutions are required. The modern age of science requires innovative minds. The field of environmental engineering is also advancing with modern science and technology innovations. Measuring of methane concentration and flow rate is nothing new, yet a complicated process. The need for more accurate measurement is a necessity in proper operation of bio digesters for methane generation. The traditional process of the measuring methane content in biogas is time consuming yet complicated. The need for development and application of methane measurement techniques is not only limited to biogas but has other monitoring value as well in other health and safety applications in built environments. Winsen Electronics and Hanwei Electronics are two of the leading sensor-manufactures of China who are providing a wide range of gas detecting sensors that are locally available in Bangladesh and yet has not been applied to methane content measurement in biogas operations. In This paper we are reporting on the application of a purpose-built propane, butane detector for methane gas detection within the range of accuracy for it to be applied in methane detection in a biogas stream. This paper, reports on application and calibration of the methane detecting sensor MQ-4 with promising result. Based on the study we postulate that the sensor can be used to detect methane for an on-line monitoring of many environmental, industrial purposes such as bio digesters, integrated waste management facility. The cost of fabrication of the sensor system is only $18 making it a viable sensor with respect to cost for application in Bangladesh.

Effectiveness of online teaching & learning during COVID19 pandemic: A case study at college of science & technology, Royal University of Bhutan

A study was carried out to assess the effectiveness of online teaching and learning at the College of Science and Technology, Royal University of Bhutan. As a case study, two modules under the electrical engineering program taught at the sixth and eighth semesters respectively were chosen. A non-statistical purposive sampling method with a mixed-mode research approach was used to assess the effectiveness of online teaching and learning during the COVID 19 pandemic with 73 respondents. Analysis of the data revealed that students were coping up well with the sudden shift of lesson delivery from traditional offline mode to online mode and learning outcomes were achieved with 43% of the respondents agreeing to it. The offline mode of teaching and learning is still the choice of mode of learning followed by mixed-mode learning. Online learning is also able to engage students meaningfully with 44% of the respondents saying they were able to communicate in the online class effectively. Generally, students were not satisfied with the online lesson mainly citing weak internet connectivity, increased distractions at home, and lack of motivation. The case study also revealed that online learning gave more flexibility, it is more convenient, and learning at its own pace is one of the greatest benefits of online learning which shows that CST has a good foundational platform for online teaching and learning. The study also highlighted the importance of changing the instructional strategies to suit the online lesson delivery for learning to be effective.

Economic and environmental benefits of 3-wheeler electric vehicles during covid-19: A case study of Rajshahi, Bangladesh

This paper provides an insight into the labour market impacts of the COVID-19 crisis in Bangladesh, focusing on Rajshahi City Corporation. A survey was built to collect data about job switching nature before and during the crisis to shed light on the implications of COVID-19 on employment and earnings. The findings presented here indicate substantial labour market impacts both at the extensive and intensive margin, mainly due to the nature of the crisis's occupations. And the sufferers switch their jobs to 3-wheeler EVs industry as a driver or mechanic. Bus helper job was the most susceptible job during the pandemic, followed by garments. Due to the countrywide lockdown, emissions from vehicles were restricted, it was found that the air quality has been improved throughout the country during the lockdown. And 3-wheeler electric vehicles play a vital role to ease this issue. The study also assesses the impact of lockdown measures on air quality in Rajshahi. Four different air pollutants data from the google earth engine (NO2, SO2, CO, and O3) were analyzed. The study evaluated that the lockdown measures significantly reduced air pollution because of reduced vehicular and industrial emissions in Bangladesh.

Study of Energy Efficiency Upgradation and Investment Risk

It was about 60 years ago when electricity was first introduced in Bhutan and today, more than 99.97 percent of households are electrified. Since electricity is superior to other form of energy, everybody prefers it. The electricity demand is increasing rapidly with development in all fronts. Distribution system are currently experiencing rapid changes in domestic load growth. With increasing domestic electricity consumption, Royal Government of Bhutan (RGoB) recognizes the importance of energy management and reduction at the consumer end to further minimize carbon emission and to increase the exports. While achieving 100 percent electrification of Bhutan, the increased consumer reduces the export, reducing the total revenue generated. The study identifies possible barriers of energy efficiency in domestic and industrial sectors. The lack of policy framework is one of the main reasons for the decline in interest in energy efficiency. The government subsidy is another cause of the same. This in turn led to negligence of Energy Efficiency (EE) programs by the consumers. On the contrary, consumers feel that the cost of energy is high, despite the fact that urban dwellers' expenditure capacity and productivity upgradation potential are also high. Based on a case study of residential and commercial buildings in the Phuntsholing region, as well as industrial sectors in Pasakha, this paper examines the metrics needed to make energy efficiency upgrade decisions. The study finds respondents were more likely to choose equipment that suited their budget rather than those that are energy efficient. Another big impediment to investment in energy efficiency in the region is a lack of energy efficiency awareness and information.