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11 pages, 1696 KiB

Open AccessArticle

Design of a Low-Cost Electrostatic Precipitator to Reduce Particulate Matter Emissions from Small Heat Sources

by Juraj Drga, Michal Holubčík, Nikola Čajová Kantová and Bystrík Červenka

Energies 2022, 15(11), 4148; https://doi.org/10.3390/en15114148 - 5 Jun 2022

Cited by 4 | Viewed by 3571

Abstract

Capturing particulate matter (PM) is an important issue due to the protection of human health and the quality of their life. This paper describes the innovation of an affordable particulate matter capture device for small heat sources to reduce particulate matter emissions. The [...] Read more.

Capturing particulate matter (PM) is an important issue due to the protection of human health and the quality of their life. This paper describes the innovation of an affordable particulate matter capture device for small heat sources to reduce particulate matter emissions. The design of two investigated variants of the device is based on the principle of a tubular electrostatic precipitator with one charging electrode placed in the chimney. The design of the precipitators is aimed at increasing the area of the collecting electrodes by elements dividing precipitation space, with a simultaneously increased number of charging electrodes. The influence of the elements’ application on the pressure drop and the gas flow velocity through the devices is analyzed by computational fluid dynamics (CFD). The work is further focused on the economic evaluation of precipitators and design adjustments for lower energy consumption. The achieved results show the right direction of efforts to improve the equipment designed to capture PM emissions. Full article

(This article belongs to the Special Issue The Nexus among Sustainable Development Goals and Clean Energies)

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44 pages, 15880 KiB

Open AccessArticle

Improved Prediction of Aerodynamic Loss Propagation as Entropy Rise in Wind Turbines Using Multifidelity Analysis

by Kiran Siddappaji and Mark Turner

Energies 2022, 15(11), 3935; https://doi.org/10.3390/en15113935 - 26 May 2022

Cited by 6 | Viewed by 1963

Abstract

Several physics-based enhancements are embedded in a low-fidelity general unducted rotor design analysis tool developed, py_BEM, including the local Reynolds number effect, rotational corrections to airfoil polar, stall delay model, high induction factor correction, polar at large angle of attack, exergetic efficiency calculation [...] Read more.

Several physics-based enhancements are embedded in a low-fidelity general unducted rotor design analysis tool developed, py_BEM, including the local Reynolds number effect, rotational corrections to airfoil polar, stall delay model, high induction factor correction, polar at large angle of attack, exergetic efficiency calculation and momentum-based loss. A wind turbine rotor is analyzed in high fidelity designed from py_BEM using a 3D blade generator. It is a design derived from the NREL Phase VI rotor. Three design variations are analyzed using steady 3D CFD solutions to demonstrate the effect of geometry on aerodynamics. S809 and NACA 2420 airfoil properties are used for calculating the aerodynamic loading. Momentum, vorticity and energy transport are explained in depth and connected to entropy production as a measure of performance loss. KE dissipation downstream of the rotor is shown to be a significant contributor of entropy rise. Wake analysis demonstrates mixing with the free stream flow, which begins after 3 diameters downstream of the rotor and extends to about 25 diameters until the decay is very small. Vorticity dynamics is investigated using a boundary vorticity flux technique to demonstrate the relationship between streamwise vorticity and lift generated in boundary layers. Drag components are accounted as well. It is demonstrated using rothalpy that shaft power is not only torque multiplied by rotational velocity but a viscous power loss term must also be included. A multifidelity analysis of wind turbine aerodynamics is demonstrated by capturing flow physics at several levels. Full article

(This article belongs to the Special Issue The Nexus among Sustainable Development Goals and Clean Energies)

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18 pages, 1082 KiB

Open AccessArticle

Economic Policy Uncertainty and Energy Prices: Empirical Evidence from Multivariate DCC-GARCH Models

by Salim Hamza Ringim, Abdulkareem Alhassan, Hasan Güngör and Festus Victor Bekun

Energies 2022, 15(10), 3712; https://doi.org/10.3390/en15103712 - 18 May 2022

Cited by 11 | Viewed by 2562

Abstract

Crude oil and natural gas are crucial to the Russian economy. Therefore, this study examined the interconnections between crude oil price, natural gas price, and Russian economic policy uncertainty (EPU) over the period 1994–2019 using multivariate DCC-MGARCH models. The findings show that there [...] Read more.

Crude oil and natural gas are crucial to the Russian economy. Therefore, this study examined the interconnections between crude oil price, natural gas price, and Russian economic policy uncertainty (EPU) over the period 1994–2019 using multivariate DCC-MGARCH models. The findings show that there are strong interconnections (co-movement) between the energy prices and EPU in Russia, and that it might be misleading to assume independence or neutrality between the variables. Although Russia is also a crucial player in both the natural gas and the crude oil markets, this study reveals that there is a stronger co-movement of the EPU with gas price than with the oil price. Russia is the largest exporter of natural gas and the second-largest producer; it is plausible that the natural gas price correlates with EPU more than the crude oil price. Further, the correlation between gas price and EPU and the correlation between crude oil price and EPU have similar patterns. Each declines almost in the same period and, equally, increases concurrently. In addition, the results revealed that significant global shocks and crises, such as the 2008 global financial crisis, the 2014–2017 Russian financial crisis, the 9/11 terrorist attack, and the Russo–Ukrainian conflicts, influence the interconnections between the energy prices and Russian EPU. Full article

(This article belongs to the Special Issue The Nexus among Sustainable Development Goals and Clean Energies)

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19 pages, 5515 KiB

Open AccessArticle

Performance Evaluation of Solar-Powered Atmospheric Water Harvesting Using Different Glazing Materials in the Tropical Built Environment: An Experimental Study

by Husam S. Al-Duais, Muhammad Azzam Ismail, Zakaria Alcheikh Mahmoud Awad and Karam M. Al-Obaidi

Energies 2022, 15(9), 3026; https://doi.org/10.3390/en15093026 - 21 Apr 2022

Cited by 3 | Viewed by 3197

Abstract

Water scarcity is a global issue, and its severity is expected to worsen in the near future, prompting further efforts to find new sources of freshwater. Solar-Powered Atmospheric Water Harvesting (SPAWH) is a promising passive approach for atmospheric water generation. This study aims [...] Read more.

Water scarcity is a global issue, and its severity is expected to worsen in the near future, prompting further efforts to find new sources of freshwater. Solar-Powered Atmospheric Water Harvesting (SPAWH) is a promising passive approach for atmospheric water generation. This study aims to examine the thermal performance of different glazing materials and water production in SPAWH. The research consists of two phases: a laboratory test of various glazing materials and an experimental study to assess system efficiency in producing water in the tropics. The preliminary results indicated that glass demonstrated better thermal performance than acrylic in the lab, with higher thermal conductivity and less heat loss. The experimental findings showed that the maximum water produced by the proposed SPAWH (60 cm length, 60 cm width and 30 cm height) placed on a 30° tilt angle using glass (3 mm) and acrylic (3 mm) was 0.61 L/m²/day and 0.44 L/m²/day, respectively. The cost analysis revealed that produced water costs $0.18/kg for glass and $0.40/kg for acrylic, respectively. Atmospheric water could be harvested using SPAWH in the tropics, which would help to provide new opportunities for sustainable water supplies and development in these regions. Full article

(This article belongs to the Special Issue The Nexus among Sustainable Development Goals and Clean Energies)

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17 pages, 2608 KiB

Open AccessArticle

A Cost-Benefit Analysis of Bakhtiari Hydropower Dam Considering the Nexus between Energy and Water

by Sanaz Tajziehchi, Abdolreza Karbassi, Gholamreza Nabi, ChangKyoo Yoo and Pouya Ifaei

Energies 2022, 15(3), 871; https://doi.org/10.3390/en15030871 - 25 Jan 2022

Cited by 13 | Viewed by 4578

Abstract

Hydropower stations have supplied most of the green electricity in various parts of the world. Nonetheless, the economic profit of hydro-electricity lies beyond its social costs in many cases. Despite the short-term economic benefits of large dams, their sustainable pros and cons are [...] Read more.

Hydropower stations have supplied most of the green electricity in various parts of the world. Nonetheless, the economic profit of hydro-electricity lies beyond its social costs in many cases. Despite the short-term economic benefits of large dams, their sustainable pros and cons are doubted. This study aims to investigate the long-term profitability of large hydropower stations by considering the nexus between the environmental, economic, and social aspects. Much progress has been made in simplifying feasibility studies of hydropower stations by developing comprehensive software and models according to the United Nations Sustainable development goals. Developed by International Atomic Energy Agency (IAEA), the SimPacts has become one of the most frequently-used simple models to estimate the external costs of electricity generation since 2003. Hydropower’s Environmental Costs Analysis Model (HECAM) is a popular user-friendly version of the model that includes more details for benefits estimation. In the present investigation, sedimentation and evaporation effects of constructing hydropower dams are added to previous cost estimation factors to upgrade the HECAM model to HECAM II. Bakhtiari hydropower dam (located in Lorestan province in Iran) is employed as a case study to verify the new model. The results showed that the total cost and revenue, as well as the benefit to cost ratio, were 79.13 US$/MWh, 203 US$/MWh, and 2.57, respectively. The new HECAM II model showed that the operation of Bakhtiari Dam would alleviate the socio-environmental doubts through a long-term plan in the region. Full article

(This article belongs to the Special Issue The Nexus among Sustainable Development Goals and Clean Energies)

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21 pages, 5061 KiB

Open AccessArticle

Thermodynamic Insight in Design of Methanation Reactor with Water Removal Considering Nexus between CO₂ Conversion and Irreversibilities

by Sayed Ebrahim Hashemi, Kristian M. Lien, Magne Hillestad, Sondre K. Schnell and Bjørn Austbø

Energies 2021, 14(23), 7861; https://doi.org/10.3390/en14237861 - 24 Nov 2021

Cited by 4 | Viewed by 2413

Abstract

The inevitable nexus between energy use and CO₂ emission necessitates the development of sustainable energy systems. The conversion of CO₂ to CH₄ using green H₂ in power-to-gas applications in such energy systems has attracted much interest. In this context, [...] Read more.

The inevitable nexus between energy use and CO₂ emission necessitates the development of sustainable energy systems. The conversion of CO₂ to CH₄ using green H₂ in power-to-gas applications in such energy systems has attracted much interest. In this context, the present study provides a thermodynamic insight into the effect of water removal on CO₂ conversion and irreversibility within a CO₂ methanation reactor. A fixed-bed reactor with one intermediate water removal point, representing two reactors in series, was modeled by a one-dimensional pseudo-homogeneous model. Pure CO₂ or a mixture of CO₂ and methane, representing a typical biogas mixture, were used as feed. For short reactors, both the maximum conversion and the largest irreversibilities were observed when the water removal point was located in the middle of the reactor. However, as the length of the reactor increased, the water removal point with the highest conversion was shifted towards the end of the reactor, accompanied by a smaller thermodynamic penalty. The largest irreversibilities in long reactors were obtained when water removal took place closer to the inlet of the reactor. The study discusses the potential benefit of partial water removal and reactant feeding for energy-efficient reactor design. Full article

(This article belongs to the Special Issue The Nexus among Sustainable Development Goals and Clean Energies)

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21 pages, 675 KiB

Open AccessArticle

An Assessment of the Energy Poverty and Gender Nexus towards Clean Energy Adoption in Rural South Africa

by Omowunmi Mary Longe

Energies 2021, 14(12), 3708; https://doi.org/10.3390/en14123708 - 21 Jun 2021

Cited by 22 | Viewed by 4971

Abstract

South Africa has about 2.5 million households without electricity access, most of which are located in rural areas and urban informal settlements. The nexus of energy poverty and gender is at play in the affected communities, as women and girls are culturally stereotyped [...] Read more.

South Africa has about 2.5 million households without electricity access, most of which are located in rural areas and urban informal settlements. The nexus of energy poverty and gender is at play in the affected communities, as women and girls are culturally stereotyped with the task of collecting unclean fuels (e.g., firewood) and using these for their households’ energy demands. Therefore, this study prioritized rural women and girls as respondents in the provinces most affected by gendered energy poverty (GEP) in the country. The study was carried out in selected rural unelectrified areas of Limpopo, Mpumalanga, and KwaZulu-Natal provinces using structured interviews. The study revealed that GEP in the rural areas has exposed women and girls living there to security concerns, health hazards, premature death, domestic fire accidents, time poverty, income poverty, illiteracy, drudgery in households and farm tasks, etc., at different levels of severity. It also showed the effects of perceptions, age, income, and culture on the choice of energy use among the respondents. Mitigation strategies against GEP in rural South African communities through clean energy adoption are also proposed in this paper. Full article

(This article belongs to the Special Issue The Nexus among Sustainable Development Goals and Clean Energies)

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3 pages, 194 KiB

Open AccessOpinion

Jevons Paradox: Sustainable Development Goals and Energy Rebound in Complex Economic Systems

by Louise Ellegaard Fich, Silvia Viola and Niclas Scott Bentsen

Energies 2022, 15(16), 5821; https://doi.org/10.3390/en15165821 - 11 Aug 2022

Cited by 7 | Viewed by 3523

Abstract

Jevons Paradox has fundamental implications on sustainable development and the UN Sustainable Development Goals (SDGs). The paradox states that technological improvements aiming to increase the energy efficiency risk causing a rebound effect, and an increase in demand, production, and resource exploitation. Third world [...] Read more.

Jevons Paradox has fundamental implications on sustainable development and the UN Sustainable Development Goals (SDGs). The paradox states that technological improvements aiming to increase the energy efficiency risk causing a rebound effect, and an increase in demand, production, and resource exploitation. Third world countries undergoing early-stage technological development may be particularly vulnerable, but it is also relevant in complex economic systems, where policymaking on climate and energy building on insufficient knowledge and attention to rebound effects can impair the desired outcome in terms of climate change mitigation, resource use and sustainable development. Full article

(This article belongs to the Special Issue The Nexus among Sustainable Development Goals and Clean Energies)

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