• Energy Research

Abstract In this study, nucleate boiling heat transfer (NBHT) based self-cooling thermal management system is designed and thermodynamically analyzed for high concentrating photovoltaics (CPV). The overall self-cooling system, consisting of two rows of CPV i.e. CPV 1 and CPV 2, iscoupled with the absorption cooling (AbC) system. Thermal energy from CPV 1 is supplied to AbC system to produce cooling, which is then used to reduce the temperature of CPV 2. Both CPV systems work simultaneously under the same solar energy conditions, hence, the demand and supply of energy are continuously in phase. Under the designed conditions, CPV 1, with an installed capacity of 66.4 kW, an operating temperature of 375.3 K and electrical efficiency of 35.5%, has the ability to cool down about 50.6 kW of CPV 2 system with an operating temperature of 335.8 K and 37.5% of electrical efficiency. A parametric study is performed to analyze the performance of the overall system at various working conditions and installed capacities. Furthermore, the designed system is analyzed for two different types of multi-junction solar cells and three different types of coolants: water, ethanol, and n-pentane. Due to higher latent heat, water has been proven to perform better working fluid with higher ability of concentration ratio. The optimum NBHT operating temperatures for CPV1 and CPV2 were found to be about 353 K and 349 K with maximum overall system efficiency of 36.64%.

Over the past decade, the adverse impacts of climate change and excessive urbanization have contributed to several unfamiliar and costly floods in the Gulf Cooperation Council (GCC), especially in Qatar. With limited historical rainfall records and unprecedented precipitation intensities impacting the efficiency of hydrological models, the multi-criteria decision analysis (MCDA) presents a suitable alternative approach to assess and identify flood-susceptible areas. In this study, we applied MCDA to several factors that contribute to flood susceptibility, namely: elevation, slope, groundwater depth, distance to a drainage system, and land use. These criteria were assigned different weights based on their contribution and previous literature and later underwent a sensitivity analysis. The study’s results correlate well with recent flooding events, proving the method’s efficiency in identifying hotspots. This study is expected to provide a rapid tool to support the decision-making process for future urban expansion, sustainable development, and resilience planning in Qatar.

Issues like air pollution and high CO2rates are forcing the government of Qatar to mitigate these pollution rates as Qatar is considered the highest country that has can emissions per capita. As a result, huge efforts are executed to reduce these high rates of pollution so many renewable technologies projects are introduced, and solar PV plant is a major one. In this paper, Doha metro project is taken as a case study to implement a hybrid system within one of the metro stations to assess the economic profitability of it and then it can be a proposal for the country of Qatar to implement such a hybrid system within the governmental projects to mitigate the pollution rate. The methodology adopted in this paper is to evaluate the profitability of the hybrid system proposed by using HOMER software where it can model, simulate and optimize the proposed system with the desired components. Main finding is that due to the low electricity tariffs with and without the governmental subsidies, the implementation of PV system in Qatar is not economically feasible unless the PV system capacity is enlarged into a big scale or the tariff prices being increased with Carbon tax regulations.

Environmental and economic cycles under varying geopolitical uncertainties can lead to unsustainable patterns that significantly and negatively affect the welfare of nations. With the ever-increasing negative environmental and economic impacts, the ability to achieve sustainability is hindered if the implications are not properly assessed in challenging geopolitical crises. The infrequent and fluctuating nature of these challenging geopolitical settings causes disregard and neglect for exploration within this issue. In this study, a comparative life cycle assessment was conducted as a method to evaluate the environmental and economic impacts of construction material flow across country boundaries. Based on the results found from the life cycle assessment, an environmental forecast and sensitivity analysis were established. Considering the State of Qatar as a case study, asphalt and bitumen, cement, limestone, sand, and steel were analyzed from gate-to-gate depending on transportation mode and distances used within both the pre-crisis and post-crisis sub-periods, comparing carbon emissions and costs. The results showed that the mode of transport plays a significant role in terms of carbon dioxide emissions as opposed to distance traveled. However, the increase in distance coupled to the majority shift from land to sea-based transport resulted in an overall increase in carbon emissions and costs post-crisis. In addition, the analysis of the environmental and economic impact assessment using the average CO2 equivalent (CO2-e) per kilogram and the unit price of the five primary construction materials has shown a significant, 70.68% increase in global warming potentials (GWP) after the crisis, coupled with an increase in the overall cost. An assessment of environmental and economic impacts during geopolitical uncertainties allows for the significant ability to realize sustainable measures to greatly reduce economic and environmental degradation.

The frequency and severity of climate change are projected to increase, leading to more disasters, increased built environment system (BES) vulnerability, and decreased coping capacity. Achieving resilience objectives in the built environment is challenging and requires the collaboration of all relevant sectors and professionals. In this study, various stakeholders were engaged, including governmental authorities, regulatory bodies, engineering firms, professionals, contractors, and non-governmental and non-profit organizations (NGOs and NPOs, respectively). The engagement was carried out through the answering of a questionnaire survey that reflects their perceptions about climate change adaptation, the built environment resilience qualities (RQs), and the degree of resilience of the existing built environment and their perceived capacities. The results were analyzed using several statistical tests. The results revealed that advancing public understanding and management tools, reducing economic losses, and developing necessary plans still require improvement. Additionally, the BESs were ranked concerning accepting the change and uncertainty inherited from the past or generated over time. This study emphasized the perception that the decision-making domain is crucial for delivering a reflective built environment. Additionally, features such as advancing public understanding and management tools, reducing economic losses, and developing necessary plans still require improvement. Furthermore, there is a belief in the importance of the task forces within the community as part of an emergency response plan, and a less reflective system would have less recovery speed. Therefore, the rapidity characteristic of a built environmental system to accept the change and uncertainty inherited from the past or generated over time is correlated to the system’s reflectivity quality. This study emphasizes the significant correlation between the different RQ traits. It also encourages researchers to formulate more objective methods to reach a set form for measuring RQs as an engineering standard.

Artificial island development (AID) to tackle rampant urbanization on scarce land puts all marine biodiversity at huge risk and is recognized as a global conservation issue worldwide. This study critically reviews the gaps that undermined biodiversity and ecology during construction activities of the artificial islands in the Gulf region that could be alleviated if apposite environmental values and sustainable strategies of different regions of the world had paid enough heed to economic and social aspects. The method used for this study was an analytical descriptive literature survey, and the resources were chosen after three phases of quality assessment. This survey found various barricades to sustainable AID, such as lack of scientific data, adequate site selection, ineffective environmental evaluations, noncompliance with legislation, and economic gains over the environmental aspects. It was concluded that to protect the marine ecosystem from inevitable degradation, strict compliance with international and national legislation, research and baseline data collection, strengthening of the existing environmental assessment, continuous capacity building, and modern practices of different countries should be brought to the forefront. Furthermore, this study aims to provide guidance to policymakers and governmental organizations to mitigate emerging environmental issues during AID through strategic decision-making processes.

The population growth, rising living standards, and climate change impacts will considerably affect the energy needs for the built environment in the coming decades. Because of the climatic changes, the shift in humidity levels and dry/wet bulb temperatures would change the required energy to maintain the same spatial comfort conditions. Furthermore, the heating load may be lowered due to the higher winter temperatures; however, the cooling load will be significantly augmented for some regions. Thus, it is imperative to quantify the impacts of building heating and cooling loads concerning climate change. This will help emphasize increasing energy capacity, improving efficiency, and developing energy policies to reduce and adapt to the climate change implications. The present study focuses on analyzing the recent works addressing and exploring the effects of climate change on the built environment’s energy consumption. This paper examines and discusses the accepted approaches and projections of building energy change. The survey shows that the estimations of heating/cooling loads are significantly affected by the type of building, city, and other regional factors. Finally, the challenges associated with predicting building energy requirements are presented and discussed.

The oil and gas industry generates a significant amount of harmful greenhouse gases that cause irreversible environmental impact; this fact is exacerbated by the world’s utter dependence on fossil fuels as a primary energy source and low-efficiency oil and gas operation plants. Integration of solid oxide fuel cells (SOFCs) into natural gas plants can enhance their operational efficiencies and reduce emissions. However, a systematic analysis of the life cycle impacts of SOFC integration in natural gas operations is necessary to quantitatively and comparatively understand the potential benefits. This study presents a systematic cradle-to-grave life cycle assessment (LCA) based on the ISO 14040 and 14044 standards using a planar anode-supported SOFC with a lifespan of ten years and a functional unit of one MW electricity output. The analysis primarily focused on global warming, acidification, eutrophication, and ozone potentials in addition to human health particulate matter and human toxicity potentials. The total global warming potential (GWP) of a 1 MW SOFC for 10 years in Qatar conditions is found to be 2,415,755 kg CO2 eq., and the greenhouse gas (GHG) impact is found to be higher during the operation phase than the manufacturing phase, rating 71% and 29%, respectively.