Diffraction of Sound as a Side Effect of Noise Pollution at Road Junctions of Dhaka City

A good number of buildings are located very close to road junctions in Dhaka City. Due to poor setbacks, building edges hinder visibility. Traffic noise travelling from the main road to a secondary road and vice versa diffracts at building edges creating virtual images of the noise source. This may cause confusion and lead to accidents. It is established that noise threatens human health. But it is not much explored how this unique phenomenon of sound diffraction at road junctions, as a side effect of noise pollution, may create confusion and cause accidents. From instrumental measurements and practical observations, this study identifies evidence of sound diffraction, the virtual position of noise source and its effect on erroneous perception at road junctions. This paper suggests proper setbacks of buildings, appropriate geometry of building edge and suitable acoustical properties of finish materials to eliminate diffraction of sound at road junctions of Dhaka city

Maximizing Daylight Use Potential in Retail Shopping Environments in the Context of Dhaka, Bangladesh

In recent times with the increase in the population, the number of retail shopping environments has increased significantly in Dhaka city. But these shopping environments are developing into high consumption areas of electricity resulting from artificially light design approach. In this study, it was found that energy consumption is rising because of the minimal or no use of daylight and natural ventilation. A field-based case study was conducted to review the daylight inclusion in the design of retail shopping environments representing the historical periods of 1950-70, 1971-80, 1981-90, 1991-2000, 2001-2011. In this research, in addition to field work, parametric study was done to identify the effect of design factors/parameters relating to daylight. The main focus was to develop a causal relation between the parameters of the shopping environments to maximize the use of daylight. The parameters which were considered in this study were: width, height and depth of the shops; the depth of the corridor between two rows of shops; and the height and width of the light wells. All the parametric relations were derived to the width of the shop. Daylight level were measured and compared with the given level in the Bangladesh National Building Code (BNBC) code. It was found that shopping environments play an important role in energy consumption in urban areas and little or no utilization of daylight contributes to this energy demand. This is of particular significance in an environment where dwindling fossil sources of energy and an increasing energy demand created by positive economic growth pose a challenge for the building industry stakeholders. 765-77

Although feasible, falling renewables costs might not benefit Bangladesh\u27s energy sector\u27s decarbonisation: Is this another ‘debt-fossil fuel production trap’?

Cost of decarbonisation, Energy generation sector, Privatisation, Carbon pricing, Energy investment},abstract = {As Bangladesh strives to transition from a least developed to a developed nation by 2041, a growing population and rising disposable income have spurred a growing middle class, escalating the demand for accessible energy. The government and the private sector have heavily invested in a fossil fuel-centric energy mix to meet this anticipated surge in demand. However, our research challenged this prevailing approach by developing a country-scale scenario-based input-output long-horizon energy planning model for demonstrating the economic viability of decarbonising Bangladesh\u27s electricity generation sector by 2050, with a preference for renewables over fossil fuels, particularly in a low-emissions scenario. This study was among the first to evaluate which was the most recent Integrated Energy and Power Master Plan (IEPMP) with a long-horizon energy planning model and suggested that implementing strategic socio-economic development measures, such as privatisation, deregulation, transparency, energy demand reduction, equitable subsidy removal, and carbon pricing, could yield a 24 % cost reduction for developing a near-zero emissions electricity generation sector by 2050. Despite these potential benefits, current and future policies, entirely influenced by master plans developed by the Japan International Cooperation Agency, continue to rely heavily on imported coal, liquefied natural gas (LNG), hydrogen, ammonia, and nuclear energy, which raised concerns about the country being entangled in a ‘debt-fossil fuel production trap.’ We recommended a critical re-evaluation of existing energy policies. This caution was grounded in the suggestion that the nation should instead harness in-country resources and explore renewable-rich alternatives within its regional neighbouring countries, steering away from potential geopolitical, economic, and environmental pitfalls.Kumar Biswajit Debnath and Monjur Mourshe

Although feasible, falling renewables costs might not benefit Bangladesh's energy sector's decarbonisation: Is this another ‘debt-fossil fuel production trap’?

As Bangladesh strives to transition from a least developed to a developed nation by 2041, a growing population and rising disposable income have spurred a growing middle class, escalating the demand for accessible energy. The government and the private sector have heavily invested in a fossil fuel-centric energy mix to meet this anticipated surge in demand. However, our research challenged this prevailing approach by developing a country-scale scenario-based input-output long-horizon energy planning model for demonstrating the economic viability of decarbonising Bangladesh's electricity generation sector by 2050, with a preference for renewables over fossil fuels, particularly in a low-emissions scenario. This study was among the first to evaluate which was the most recent Integrated Energy and Power Master Plan (IEPMP) with a long-horizon energy planning model and suggested that implementing strategic socio-economic development measures, such as privatisation, deregulation, transparency, energy demand reduction, equitable subsidy removal, and carbon pricing, could yield a 24 % cost reduction for developing a near-zero emissions electricity generation sector by 2050. Despite these potential benefits, current and future policies, entirely influenced by master plans developed by the Japan International Cooperation Agency, continue to rely heavily on imported coal, liquefied natural gas (LNG), hydrogen, ammonia, and nuclear energy, which raised concerns about the country being entangled in a ‘debt-fossil fuel production trap.’ We recommended a critical re-evaluation of existing energy policies. This caution was grounded in the suggestion that the nation should instead harness in-country resources and explore renewable-rich alternatives within its regional neighbouring countries, steering away from potential geopolitical, economic, and environmental pitfalls

A data-driven framework for modelling community energy demand

Data driven models that integrate advanced analytics involving statistical and machine learning algorithms are widely applied for simulating and predicting energy demand at the community level. These models are used to inform various energy efficiency measures, infrastructure development, planning and investment decision. The paper presents an innovative framework for simulating and projecting climate change impacts on the future dynamics of community energy demand. The modelling framework selectively couples some of the most advanced analytical approaches and its potential are demonstrated using a case study community “Auroville” located in India

Remote work might unlock solar PV\u27s potential of cracking the \u27Duck Curve\u27

Integrating renewable energy technologies into a decentralised smart grid presents the ‘Duck Curve’ challenge — the disparity between peak demand and solar photovoltaic (PV) yield. Smart grid operators still lack an effective solution to this problem, resulting in the need to maintain standby fossil fuel-fired plants. The COVID-19 pandemic-induced lockdowns necessitated a shift to remote work (work-from-home) and home-based education. The primary objective of this study was to explore mitigating strategies for the duck curve challenge by investigating this notable shift in behaviour by examining the effect of remote work and education on grid and decentralised solar PV electricity use in 100 households with battery energy storage in the southwest of the UK. This study examined 1-min granular grid electricity and decentralised solar energy consumption data for April–August 2019 and 2020. The findings revealed statistically significant disparities in energy demand. Notably, there was a 1.4—10% decrease in average electricity consumption from April to August 2020 (during and following the lockdown) compared to the corresponding months of 2019. Furthermore, household grid electricity consumption was reduced by 24—25%, while self-consumption from solar PV systems increased by 7—8% during the lockdown in April and May 2020 compared to 2019. This increase in self-consumption was particularly prominent in the morning and afternoon, possibly attributed to the growing prevalence of work-from-home and home-based education. The dynamic shifts in energy consumption patterns emphasised the role of decentralised solar PV energy in meeting the evolving needs of households during unprecedented societal changes. Additionally, remote work might unlock decentralised solar PV\u27s potential in resolving the ‘Duck Curve’, urging further investigation into the implications for energy infrastructure and policy development

A Mixed-Methods Approach for Evaluating the Influence of Residential Practices for Thermal Comfort on Electricity Consumption in Auroville, India

With rapid global economic growth and a rise in disposable household income, particularly within a progressively warming planet, the escalating demand for energy to achieve thermal comfort has become a salient concern in the Global South, notably in emerging economies like India. This burgeoning need for cooling solutions has not only underscored the vital role of energy consumption but has also accentuated the imperative of comprehending the ensuing implications for electricity policy and strategic planning, particularly within the ambit of the Global South. This study explored the nuanced landscape of active cooling within an intentional community, Auroville, in southern India, aiming to discern the factors underpinning household preferences and practices in the pursuit of thermal comfort. Employing a mixed-methods approach, this study contributed empirically and methodologically to the interdisciplinary discourse by analysing residential electricity consumption patterns and cooling practices within selected households in the specified community. The study unfolded in three methodological stages: firstly, an analysis of climatic data coupled with an environmental stress index (ESI) assessment; secondly, the monitoring of end-user electricity consumption followed by rigorous data analysis; and lastly, the utilisation of qualitative in-depth interviews and observational techniques. This study’s outcome yielded empirical insights into the unprecedented shifts in the ESI for Auroville since 2014. Furthermore, the study unravelled the intricate complexities inherent in occupant behaviour within residential structures, thereby offering valuable insights into the practices that shape householders’ cooling preferences. This research enriched the understanding of the dynamics of energy consumption in the pursuit of thermal comfort and contributes to the broader discourse on sustainable development and energy policy in the context of climate change

Climate change, extreme heat, and South Asian megacities: Impact of heat stress on inhabitants and their productivity

Of the 33 global megacities, 10 were situated in South Asia. Extreme heat waves have become an annual phenomenon due to climate change in South Asian megacities, causing severe health issues and even deaths. In this study, we evaluated 29 years (1990–2019) of historical data on heat stress in ten selected megacities (existing and prospective)—New Delhi, Dhaka, Mumbai, Kolkata, Ahmedabad, Chennai, Bengaluru, Hyderabad, Chittagong, and Pune—in India and Bangladesh. We used heat index (HI) and environmental stress index (ESI) analyses to evaluate stress and vulnerability. Our results showed New Delhi, Mumbai, Kolkata, Ahmedabad, and Chennai in India; Dhaka and Chittagong in Bangladesh were already experiencing an elevated number of hours of “danger” levels of heat stress, which may lead to heat cramps, exhaustion, stroke, and even death. Furthermore, the frequency of “danger” levels of heat stress and vulnerable levels of ESI has increased significantly since 2011 in the selected megacities, which elevated the heat-related vulnerability among the millions of inhabitants in terms of work hours lost for light, moderate, and heavy work due to heat stress. The vulnerable population in the studied megacities might have to reduce annual work hours by 0.25–860.6 h (light work), 43–1595.9 h (moderate work), and 291–2402 h (heavy work) due to extreme heat in 1990–2019. We also discussed the implication of the work-hour loss on productivity, income, gross domestic product, and sustainable development goal progress because of heat stress and its causes and suggested recommendations to reduce its impact

Potential of relative humidity as a proxy of air temperature in developing passive and adaptive building fa\ue7ades with bio-based responsive materials

There has been significant development in thermo-responsive materials for drug delivery and bio-medical use; some are bio-based. However, the use of thermo-responsive bio-based materials in the built environment, especially on the building fa\ue7ade, is almost non-existent due to complexities including difficulties manufacturing in bulk, cost and durability to weathering. On the other hand, humidity-responsive materials such as wood are abundant and are used in buildings globally. Furthermore, new bio-based humidity-responsive materials such as bacterial cellulose (BC) and natural fibres have the potential for building applications. In this study, we hypothesised that if there was a relationship between the relative humidity and air temperature in a location, humidity-responsive materials could be used to develop passive and adaptive building fa\ue7ades, which would indirectly respond to temperature. Here, we selected two sites (New Delhi, India and Newcastle upon Tyne, UK) with temperate climates — according to the K\uf6ppen-Geiger system— to analyse the relationship between relative humidity and air temperature from 37 years (1985-2022) of weather data and typical meteorological year (TMY) climate data for 2004-2018. This relationship assessment used the Pearson correlation (coefficient and p-value) analysis. Our results showed a strong and statistically significant negative correlation between the relative humidity and air temperature in all months in 37 years in New Delhi, with the strongest correlation in the summer and monsoon months. However, the correlation was strong only in some summer months for Newcastle upon Tyne. We concluded that humidity-responsive bio-based materials have the potential to be used to actuate passive and adaptive building fa\ue7ades in New Delhi (for all-year-round use) and Newcastle (only during summer), which respond indirectly to external temperature