| 1. |
- Ackermann, Thomas, et al.
(författare)
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An overview of wind energy-status 2002
- 2002
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Ingår i: Renewable & sustainable energy reviews. - 1364-0321 .- 1879-0690. ; 6:1-2, s. 67-128
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Forskningsöversikt (refereegranskat)
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| 2. |
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| 3. |
- Abdalla, A. M., et al.
(författare)
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Nanomaterials for solid oxide fuel cells: A review
- 2018
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Ingår i: Renewable and Sustainable Energy Reviews. - : Elsevier BV. - 1879-0690 .- 1364-0321. ; 82, s. 353-368
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Forskningsöversikt (refereegranskat)abstract
- Nanotechnology is utilized well in the development and improvement of the performance in Solid Oxide Fuel Cells (SOFCs). The high operating temperature of SOFCs (700–900 °C) has resulted in serious demerits regarding their overall performance and durability. Therefore, the operating temperature has been reduced to an intermediate temperature range of approximately 400–700 °C which improved performance and, subsequently, commercialized SOFCs as portable power sources. However, at reduced temperature, challenges such as an increase in internal resistance of the fuel cell components arise. Although, this may not be as serious as problems encountered at high temperature, it still significantly affects the performance of SOFCs. This review paper addresses the work of researchers in the application of nanotechnology in fabricating SOFCs through distinct methods. These methods have successfully omitted or at least reduced the internal resistance and showed considerable improvement in power density of the SOFCs at reduced temperatures.
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| 4. |
- Abolhosseini, Shahrouz, et al.
(författare)
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The main support mechanisms to finance renewable energy development
- 2014
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Ingår i: Renewable & sustainable energy reviews. - : Elsevier BV. - 1364-0321 .- 1879-0690. ; 40, s. 876-885
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Forskningsöversikt (refereegranskat)abstract
- Considering that the major part of greenhouse gases is carbon dioxide, there is a global concern aimed at reducing carbon emissions. In addition, major consumer countries are looking for alternative sources of energy to avoid the impact of higher fossil fuel prices and political instability in the major energy supplying countries. In this regard, different policies could be applied to reduce carbon emissions, such as enhancing renewable energy deployment and encouraging technological innovation and the creation of green jobs. This study compares three main support mechanisms employed by governments to finance renewable energy development programs: feed-in-tariffs, tax incentives, and tradable green certificates. Considering that many of the promising technologies to deploy renewable energy require investment in small-scale energy production systems, these mechanisms could be used to enhance renewable energy development at the desired scale. Employing a carbon emission tax or emission trading mechanism could be considered ideal policies to mitigate emissions at the lowest cost. The comparison of feed-in-tariffs and renewable portfolio standard policies showed that the former is good when a policy to develop renewable energy sources with a low level of risk for investors is considered. However, the latter is an appropriate policy when a market view policy is applied by the government. Finally, considering technological progress and the cost reduction for power generation by renewable energy sources, we suggest that support mechanism policies should be reconsidered from the financial point of view. (C) 2014 Elsevier Ltd. All rights reserved.
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| 5. |
- Adom, Philip Kofi, et al.
(författare)
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What drives the energy saving role of FDI and industrialization in East Africa?
- 2016
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Ingår i: Renewable & sustainable energy reviews. - : Elsevier. - 1364-0321 .- 1879-0690. ; 65, s. 925-942
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Tidskriftsartikel (refereegranskat)abstract
- Analysis of the unconditional impacts of foreign direct inflows (FDIs) and industrialization on energy intensity does not show the hidden roles of some economic conditions such as income and trade openness. In this study, we focused on the conditional impacts of FDIs and industrialization on energy productivity using a panel data consisting of thirteen (13) East African countries covering 1980–2011. The baseline result shows that higher income and a well-integrated economy are pro-energy productive, but FDIs and intense industrialization are anti-energy productive in the sub-region. This result remains robust even when we exclude the high income group and control for income group effects. Income significantly promotes energy productivity more in low income group than middle income group. Intense industrialization and FDIs significantly decreases energy productivity only in low income countries. Trade openness significantly promotes energy productivity only in middle income group. We have shown that FDIs and income, intense industrialization and FDIs, and intense industrialization and globalization are complementary forces that promote energy productivity in East Africa but this is more evident for the middle income group than the low income group in the sub-region. Based on the result, we recommend a quadruplet programme called the “Growth, Industrial, Foreign investment and Trade programme” (GIFTP). Last, our result suggests that unconditional analysis of energy productivity should not be seen as an end in itself but a basis for further analysis.
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| 6. |
- Aftab, A., et al.
(författare)
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Nanoparticles based drilling muds a solution to drill elevated temperature wells : a review
- 2017
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Ingår i: Renewable & sustainable energy reviews. - : Elsevier. - 1364-0321 .- 1879-0690. ; 76, s. 1301-1313
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Tidskriftsartikel (refereegranskat)abstract
- Demand of the oil and gas energy is increasing very drastically. Conventional hydrocarbon reservoirs contain below the sealing cap rock (shale) and easily move towards wellbore are at the depletion stage. Therefore, drilling engineers in collaboration with mud engineers, geologists and geophysicists are looking for innovative materials to drill unconventional hydrocarbons reservoir which are distributed at the basin scale and cannot approach easily. Geo-thermal energy wells and most of unconventional reservoirs are occurred at high pressure high temperature (HPHT) conditions. Conventional micro-macro organic drilling mud additives with heat insulator in nature can minimize efficiency while drilling HPHT wells. Oil-based muds (OBM) are strictly restricted due to high toxic level and poor emulsion stability at HT. However, this review suggests that addition of macro size organic particles and inorganic nanoparticles can enhance rheological performance, reduce filtrate loss volume and improve shale inhibition characteristics of environmental friendly water-based mud (WBM). Despite an impressive amount of experimental work has been done over drilling additives and their effect over rheological and shale inhibition, taking into account their literature review are rare. In addition, there is no review work of the knowledge gained to date. This work will hope fully trigger further development and new research topics in the area of drilling muds system.
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| 7. |
- Aghaali, Habib, 1981-, et al.
(författare)
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A review of turbocompounding as a waste heat recovery system for internal combustion engines
- 2015
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Ingår i: Renewable & sustainable energy reviews. - : Elsevier BV. - 1364-0321 .- 1879-0690. ; 49, s. 813-824
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Tidskriftsartikel (refereegranskat)abstract
- Internal combustion engines waste a large amount of fuel energy through their exhausts. Various technologies have been developed for waste heat recovery such as turbocompounds, Rankine bottoming cycles, and thermoelectric generators that reduce fuel consumption and CO2 emissions. Turbocompounding is still not widely applied to vehicular use despite the improved fuel economy, lower cost, volume, and complexity higher exhaust gas recirculation driving capability and improved transient response. This paper comprehensively reviews the latest developments and research on turbocompounding to discover important variables and provide insights into the implementation of a high-efficiency turbocompound engine. Attention should be paid to the optimization of turbocompound engines and their configurations because the major drawback of this technology is additional exhaust back-pressure, which leads to higher pumping loss in the engines. Applying different technologies and concepts on turbocompound engines makes the exhaust energy recovery more efficient and provides more freedom in the design and optimization of the engines. Turbine efficiency plays an important role in the recovery of the wasted heat so turbine design is a crucial issue in turbocompounding. In addition, variability in geometry and rotational speed of power turbines allows for more efficient turbocompound engines in different operating conditions. The conclusion drawn from this review is that turbocompounding is a promising technology for reducing fuel consumption in the coming decades in both light- and heavy-duty engines.
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| 8. |
- Ahlborg, Helene, 1980, et al.
(författare)
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Thirty-five years of research on energy and power: A landscape analysis
- 2024
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Ingår i: Renewable and Sustainable Energy Reviews. - 1879-0690 .- 1364-0321. ; 199
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Forskningsöversikt (refereegranskat)abstract
- The urgent need to mitigate climate change and decarbonise the energy sector brings the risk that wider social and environmental concerns about the sustainability of energy systems are neglected. Countries may achieve decarbonization goals while reproducing or worsening the unequal distribution of access, opportunities, costs and burdens that is inherent to current energy systems. This study is motivated by the tension between visions for change towards sustainable energy systems and historic and contemporary inequities on the ground. The study contributes a quantitative, global-scope overview of existing research that places energy users and their lives at the centre of analysis for inclusive and equitable transitions. It further identifies the themes, concepts and perspectives that dominate scholarly debate and analyses the presence and relative influence of work that explicitly considers relations of power. The stepwise review uses the Scopus database and multiple bibliometric tools, covering the period until June 2022. It adopts a novel approach to identify dominant and marginal topics, geographical contexts and theoretical lenses employed including the uptake of critical social science approaches. The results indicate that dominant studies fail to engage critically with relationships of power. Even within the debate on “energy poverty”, work based in critical theory approaches account for less than seven percentages of the total body of work. For work on “energy justice” and users, four percentages of publications account for gender. The dominant language is technical and depoliticized. The study identifies research gaps and promising avenues for further research.
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| 9. |
- Akhlaghi, Shahin, et al.
(författare)
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Deterioration of automotive rubbers in liquid biofuels : A review
- 2015
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Ingår i: Renewable & sustainable energy reviews. - : Elsevier BV. - 1364-0321 .- 1879-0690. ; 43, s. 1238-1248
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Forskningsöversikt (refereegranskat)abstract
- Concerns over the fast depletion of fossil fuels, environmental issues and stringent legislation associated with petroleum-based fuels have triggered a shift to bio-based fuels, as an alternative to meet the growing energy demand in the transportation sector. However, since conventional automobile fuel systems are adapted to petroleum-based fuels, switching to biofuels causes a severe deterioration in the performance of currently used rubber components. The degradation of the rubber materials in biofuels is complicated by the presence of different additives in biofuels and rubber compounds, by oxidation of biofuels and by the effects of thermomechanical loadings in the engine. This paper presents a comprehensive review of the effects of different types of biofuels, particularly biodiesel and bioethanol, on the physical, mechanical, morphological and thermal properties of elastomers under different exposure conditions. In addition, the literature data available on the variation of rubbers' resistance to biofuels with the changes in their monomer type and composition, cure system and additives content was also studied. The review essentially focuses on the compatibility of biofuels with acrylonitrile butadiene rubber, fluoroelastomers, polychloroprene rubber and silicon rubber, as the most commonly used automotive rubbers coming into contact with fuels during their service. The knowledge summarized in this study can help to develop a guideline on the selection of rubber for automotive parts designed to withstand biofuels.
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| 10. |
- Allard, Ingrid, et al.
(författare)
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Methods for energy analysis of residential buildings in Nordic countries
- 2013
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Ingår i: Renewable & sustainable energy reviews. - : Pergamon-Elsevier Science. - 1364-0321 .- 1879-0690. ; 22, s. 306-318
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Forskningsöversikt (refereegranskat)abstract
- To meet the goals of the directive 2010/31/EU on the energy performance of buildings, the building sector in Europe now faces a transition towards more energy efficient buildings. Research and development of new energy solutions and technology will be necessary for the transition and the importance of analyzing building energy performance increases. This paper aims to review and evaluate different methods that are commonly used to analyze energy performance in residential buildings in Nordic countries, primarily in Sweden, Norway and Finland. A short international review of regulations is also included. The goal is to find commonly used methods and possibilities for the future. The introduced methods are summarized, categorized and compared based on their advantages and disadvantages. Although the three Nordic countries have similar climate conditions and building traditions, the review shows relatively large variations in the definitions of energy performance for residential buildings, as well as variations in how measurements and calculations are used in the methods for energy performance analysis. In the conducted review, methods, or parts of methods, are also found to be used. The methods used to analyze energy performance are found to be more similar than the concepts of energy performance itself in the three countries. These aspects may be considered in further work to develop an international policy practice for energy performance of residential buildings in cold climate.
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| 11. |
- Almssad, Asaad, et al.
(författare)
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Environmental reply to vernacular habitat conformation from a vast areas of Scandinavia
- 2015
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Ingår i: Renewable & sustainable energy reviews. - : Elsevier. - 1364-0321 .- 1879-0690. ; 48, s. 825-834
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Tidskriftsartikel (refereegranskat)abstract
- There are many original ideas and useful system inputs embedded in the building of human settlements in Scandinavian regions, where the landscape and habitat are strongly interconnected. A cold climate and strong winds are the most prominent risks that affect habitats. The Longhouse is the foremost traditional habitat in the Scandinavian region, dating back to the Iron Age, 2000 BC. This study examines the influence of climate on the conformation of habitats. Climate had a solid impact on the conceptions of habitat form and internal space. Wind and extreme temperatures had firming consequences on the housing arrangements, layouts, orientations, and building materials used in the construction process. Habitats from this region were located in an optimal arrangement, and the south orientation was used effectively. This investigation will provide an evaluative interpretation and analysis of the real facts of vernacular habitats in the context of energy efficiency and ecological concepts, considering human settlement patterns, architectural creation and building material uses.
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| 12. |
- Alves, Joao S., et al.
(författare)
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Experimental investigation on performance improvement by mid-plane guide-vanes in a biplane-rotor Wells turbine for wave energy conversion
- 2021
-
Ingår i: Renewable & sustainable energy reviews. - : Elsevier BV. - 1364-0321 .- 1879-0690. ; 150
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Tidskriftsartikel (refereegranskat)abstract
- The Wells turbine is the most frequently used or proposed self-rectifying air turbine for oscillating-water column wave-energy converter application, largely because of its conceptual and mechanical simplicity. Biplane Wells turbines allow a higher total blade solidity to be attained than monoplane turbines do, but this results in larger aerodynamic losses associated with the swirl kinetic energy loss at turbine exit. This may be overcome by the presence of a row of guide vanes between the two rotor planes, a solution that had been proposed and investigated theoretically or by numerical modelling. Results of turbine overall performance and flow details are reported from laboratory tests of a biplane Wells turbine without guide vanes and with specially designed guide vanes. The presence of the guide vanes was found to increase the peak efficiency by seven percentual points, while reducing (for fixed rotational speed) the damping provided by the turbine. Measured losses in the guide vane row were much smaller than in the rotors. Experimental results are compared with previously published numerical results. A stochastic theoretical transform was applied to obtain averaged results for the turbine performance subject to the irregular bidirectional air flow induced by real sea waves.
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| 13. |
- Amara, Sofiane, et al.
(författare)
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Legionella Disinfection by Solar Concentrator System
- 2017
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Ingår i: Renewable & sustainable energy reviews. - : Elsevier. - 1364-0321 .- 1879-0690. ; 70, s. 786-792
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Tidskriftsartikel (refereegranskat)abstract
- The current study concerns the fundamental problems of Legionnaires disease. Four decades after Legionnaires' bacteria was first identified there is still a low level of clinical awareness. Humans are infected by inhalation of aerosolized water and/or soil contaminated with the bacteria. Several control methods are available for water disinfection: biocide, ultraviolet light sterilization, copper-silver ionization, ozonation etc. but only thermal treatment can completely eliminate Legionella, which is killed almost instantly at 70 °C. The current paper describes Legionella disinfection by a solar concentrator combined with a heat recovery system that reduces the heat demand. Though this study is made for a small system (160 l of hot water per day) the system can be enlarged (more hot water and more solar collector area) and the results are thus valid also for such larger systems. Here experiments of water treatment by a solar concentrator are summarized and analyzed where the temperature exceeds 80 °C at the outlet of the heat exchanger.
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| 14. |
- Andersson, Elias, 1989-, et al.
(författare)
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Energy end-use and efficiency potentials among Swedish industrial small and medium-sized enterprises - A dataset analysis from the national energy audit program
- 2018
-
Ingår i: Renewable & sustainable energy reviews. - : PERGAMON-ELSEVIER SCIENCE LTD. - 1364-0321 .- 1879-0690. ; 93, s. 165-177
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Forskningsöversikt (refereegranskat)abstract
- Improving energy efficiency in industry is recognized as one of the most vital activities for the mitigation of climate change. Consequently, policy initiatives from governments addressing both energy-intensive and small and medium-sized industry have been enacted. In this paper, the energy end-use and the energy efficiency potential among industrial small and medium-sized companies participating in the Swedish Energy Audit Program are reviewed. The three manufacturing industries of wood and cork, food products and metal products (excluding machinery and equipment) are studied. A unique categorization of their production processes energy end-use is presented, the results of which show that the amount of energy used in various categories of production processes differ between these industries. This applies to support processes as well, highlighting the problem of generalizing results without available bottom-up energy end-use data. In addition, a calculation of conservation supply curves for measures related to production processes is presented, showing that there still remains energy saving potential among companies participating in the Swedish Energy Audit Program. However, relevant data in the database used from the Swedish Energy Audit Program is lacking which limits the conclusions that can be drawn from the conservation supply curves. This study highlights the need to develop energy policy programs delivering high-quality data. This paper contributes to a further understanding of the intricate matters of industrial energy end-use and energy efficiency measures.
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| 15. |
- Andersson, Johnn, 1983, et al.
(författare)
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Photovoltaics in Sweden – Success or failure?
- 2021
-
Ingår i: Renewable and Sustainable Energy Reviews. - : Elsevier BV. - 1879-0690 .- 1364-0321. ; 143
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Tidskriftsartikel (refereegranskat)abstract
- Promoting global energy transitions while stimulating domestic industrialization requires national policymaking that shapes technological innovation towards specific outcomes. Although this is inherently difficult, historical case studies may bring a better understanding of innovation dynamics and thereby guide the design of future policy interventions. The purpose of this paper is to review and analyze the emergence of Swedish photovoltaics technology from a policy perspective. Our main aim is to provide a retrospective account of historical developments, but we also derive more general insights about technological innovation and related policy challenges. The paper departs from an adapted analytical framework based on the technological innovation systems approach. Our review identifies four decades of Swedish research that has largely failed to drive domestic commercialization, the rise and fall of an industry that mainly served international markets, and a rapidly growing domestic market based on imported products. This situation is the result of mismatches and fragmentation among key innovation processes, which have not been addressed by strategic policy interventions. We suggest that policymakers should promote a full range of innovation processes and consider making innovation support subject to a payback mechanism that delivers a return on public investments even if industries and markets emerge abroad. Our study also demonstrates how the technological innovation systems approach can be extended to include the function commercialization and emphasizes the importance of paying attention to the directionality of technological innovation processes.
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| 16. |
- Andrei, Mariana, 1981-, et al.
(författare)
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Exploring a decarbonization framework for a Swedish automotive paint shop
- 2024
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Ingår i: Renewable & sustainable energy reviews. - : Elsevier. - 1364-0321 .- 1879-0690. ; 200
-
Tidskriftsartikel (refereegranskat)abstract
- The automotive industry is the world’s largest manufacturing activity, characterized by complex productionprocesses and some energy-intense processes which use a significant quantity of raw materials. The production processes responsible for the highest energy end-use take place in the paint shop. Depending on the type of paintshop processes, the energy use can account for up to 75 % of the plant’s total energy end-use. This study aims to contribute to an enhanced understanding of the complexity of adopting decarbonization measures and to provide support for planning and decision-making in practice. By adopting a bottom-up perspective, a longitudinal case study was conducted on a state-of-the-art automotive paint-shop between November 2019 and March 2023. To achieve the study’s aim, a bottom-up methodology was developed comprising several steps: i) analysis of decarbonization measures, ii) mapping of process energy use and CO2 emissions, and iii) economic analysis. The data-based methodology is flexible and can be applied in different automotive paint-shops. Main findings show that i) incremental energy efficiency measures have the fastest adoption level, with relatively high savings potential,and most of these are cost effective; ii) radical process innovation measures have a higher savings potential, but long-term adoption levels due to the radical innovations required in the supply chain, and the highly specialized knowledge needed in the pre-treatment process; and iii) the primary drivers for implementing the measures are to achieve the climate targets and establish a leading position in the sector, rather than focusing primarily on the cost-effectiveness of the measures.
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| 17. |
- Andrei, Mariana, 1981-, et al.
(författare)
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Knowledge demands for energy management in manufacturing industry - A systematic literature review
- 2022
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Ingår i: Renewable & sustainable energy reviews. - : Elsevier. - 1364-0321 .- 1879-0690. ; 159
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Forskningsöversikt (refereegranskat)abstract
- The social context in relation to energy policies and advances in more energy efficient technologies is changing constantly, thus driving a need for change in the manufacturing sector. This study presents a knowledge-based framework that enables the understanding of the model for knowledge that has taken industrial energy efficiency to current levels and the analysis of the model in the current context of industry transition. The framework consists of three broader forms of knowledge and specific knowledge attributes that can capture the knowledge employed in industrial energy management. The framework is applied in a systematic literature review, analyzing the forms of knowledge and main aspects of energy management in manufacturing industries from 157 articles published between 2010 and 2020 in various academic journals. Besides the framework, the results show that the technical form of knowledge is the primary type of knowledge employed in energy management and that a paradigm-changing towards Industry 4.0. is seen. Another employed form of knowledge is process knowledge, which is concerned with the prerequisite information needed to implement energy management. Finally, lead- ership knowledge is also employed in energy management and a blend in these three forms of knowledge might move us beyond traditional knowledge towards new forms of knowledge that maximize the potential for energy management in manufacturing industries. The knowledge demands brought by Industry 4.0 for all forms of knowledge are identified and discussed.
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| 18. |
- Anukam, Anthony, et al.
(författare)
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A review of the mechanism of bonding in densified biomass pellets
- 2021
-
Ingår i: Renewable & sustainable energy reviews. - : Elsevier. - 1364-0321 .- 1879-0690. ; 148
-
Tidskriftsartikel (refereegranskat)abstract
- The production of durable biomass pellets have always been challenged by several factors including the lack of understanding of the mechanism involved in how particles combine to form pellets under standard conditions of the pellet press. This is because contributing factors span several molecular, microscopic, and even nanoscopic levels as biomass undergoes pelleting. The characteristics of the bonds formed between the combining particles and their relevance to the quality of pellets remains vague, no matter how quality is defined. However, even though few researchers have attempted to explain the mechanism of bonding in densified biomass pellets using different theories, none of their hypotheses supports particle bonding from a structural chemistry perspective. There are still no clear explanations which consider the role of molecular structure and the interactions of substances as milled biomass undergo pelleting. In view of these arguments therefore, this review presents an in-depth analysis of a structural chemistry perspective of the mechanism of bonding and the use of additives in densified biomass pellets and helps identify research areas needed to facilitate better understanding of bonding in densified biomass pellets. The status of current research in biomass pelleting, types of materials suitable as additives and their structural characteristics, as well as the current technical specifications of using additives are also discussed.
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| 19. |
- Anukam, Anthony, et al.
(författare)
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Pre-processing of sugarcane bagasse for gasification in a downdraft biomass gasifier system : A comprehensive review
- 2016
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Ingår i: Renewable & sustainable energy reviews. - : Elsevier. - 1364-0321 .- 1879-0690. ; 66, s. 775-801
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Forskningsöversikt (refereegranskat)abstract
- The processing of sugarcane bagasse as a potential feedstock for efficient energy production has attracted a great deal of attention in the sugarcane industry, which has traditionally inefficiently burned bagasse in boilers for steam and electricity generation. Alternative technologies for more efficient utilisation of bagasse for energy production within the industry has also been hindered by the high degree of complexity involved in bagasse handling and pre-processing before it can be utilised as an energy feedstock. This can be attributed to unfavourable characteristics of mill-run bagasse, which includes low bulk and energy densities, a wide range of particle sizes and shapes as well as high moisture content. Gasification is regarded as one of the most promising energy recovery technologies for the widespread use of biomass because of its higher efficiency when compared to the combustion technology commonly used by the sugarcane industry. There has been a strong drive to identify efficient pre-processing methods that can be applied to bagasse to make it a suitable feedstock for energy production in thermochemical conversion systems. This work provides a comprehensive review on the pre-processing of bagasse for gasification, and the gasification technology options for its conversion into energy, with a particular emphasis on the downdraft gasification technology. (C) 2016 The Authors. Published by Elsevier Ltd.
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| 20. |
- Averfalk, Helge, 1988-, et al.
(författare)
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Large heat pumps in Swedish district heating systems
- 2017
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Ingår i: Renewable & sustainable energy reviews. - Kidlington : Pergamon Press. - 1364-0321 .- 1879-0690. ; 79, s. 1275-1284
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Tidskriftsartikel (refereegranskat)abstract
- Power-to-heat solutions like heat pumps and electric boilers are foreseen to be possible future tools to stabilise international power markets with high proportions of variable power supply. Temporary low cost electricity can be used for heat generation at times with high availability of wind and solar power through substitution of ordinary heat supply, hence contributing to increased energy system sustainability. Power-to-heat installations in district heating systems are competitive due to low specific investment and installation costs for large electric boilers, heat pumps, and heat storages. Several large-scale heat pumps were installed in Swedish district heating systems during the 1980s, since a national electricity surplus from new nuclear power existed for some years. The aim of this paper is to summarise the accumulated operation experiences from these large Swedish heat pumps to support and facilitate planning of future power-to-heat solutions with heat pumps in district heating systems. Gained experiences consider; installed capacities, capacity utilisation, heat sources used, refrigerant replacements, refrigerant leakages, and wear of mechanical components. The major conclusion is that many of the large thirty-year-old heat pumps are still in operation, but with reduced capacity utilisation due to internal competition from waste and biomass cogeneration plants in the district heating systems.
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| 21. |
- Awais, Fawad, et al.
(författare)
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Logistic characteristics and requirements of Swedish wood biofuel heating plants
- 2021
-
Ingår i: Renewable & sustainable energy reviews. - : Elsevier Ltd. - 1364-0321 .- 1879-0690. ; 138
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Tidskriftsartikel (refereegranskat)abstract
- The demand for wood biofuel for district heating plants and combined heat and power plants (CHPs) has increased, caused by an increase in both the number and size of CHPs. This places large demands on the logistics system supplying these plants with fuel, with a particular interest in the use of alternative modes of transport such as rail and sea. The aim of this paper is to identify the industry actors’ requirements, constraints, and preferences regarding the wood-biofuel supply chain and to identify the logistical challenges this entails, as well as how this impacts the opportunity for an increased use of alternative transport solutions. A survey was sent to all Swedish CHPs, combined with six interviews with transport companies, terminal operators, and forest companies. The study shows that the industry has a local focus that limits potential logistics and sourcing solutions. It is also challenged by urban sprawl, with expanding residential areas close to the CHPs putting further constraints on the operations. Significant variations in fuel demand, depending on unpredictable outside temperature and seasonal variation, is a further challenge. The low density of the fuel has a negative impact on transport costs and introduces a trade-off between chipping close to the forest to increase density versus more efficient chipping at the CHP. Intermodal transport only used by large plants, driven by a shortage of local fuel. © 2020 The Authors
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| 22. |
- Azuatalam, Donald, et al.
(författare)
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Energy management of small-scale PV-battery systems : A systematic review considering practical implementation, computational requirements, quality of input data and battery degradation
- 2019
-
Ingår i: Renewable & sustainable energy reviews. - : Elsevier. - 1364-0321 .- 1879-0690. ; 112, s. 555-570
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Forskningsöversikt (refereegranskat)abstract
- The home energy management problem has many different facets, including economic viability, data uncertainty and quality of strategy employed. The existing literature in this area focuses on individual aspects of this problem without a detailed, holistic analysis of the results with regards to practicality in implementation. In this paper, we fill this gap by performing a comprehensive comparison of seven different energy management strategies, each with different levels of practicality, sophistication and computational requirements. We analyse the results in the context of these three characteristics, and also critique the modelling assumptions made by each strategy. Our analysis finds that using a more sophisticated energy management strategy may not necessarily improve the performance and economic viability of the PV-battery system due to the effects of modelling assumptions, such as the treatment of uncertainties in the input data and battery degradation effects.
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| 23. |
- Bahaj, AbuBakr S.
(författare)
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Generating electricity from the oceans
- 2011
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Ingår i: Renewable & sustainable energy reviews. - : Elsevier BV. - 1364-0321 .- 1879-0690. ; 15:7, s. 3399-3416
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Tidskriftsartikel (refereegranskat)abstract
- Ocean energy has many forms, encompassing tides, surface waves, ocean circulation, salinity and thermal gradients. This paper will considers two of these, namely those found in the kinetic energy resource in tidal streams or marine currents, driven by gravitational effects, and the resources in wind-driven waves, derived ultimately from solar energy. There is growing interest around the world in the utilisation of wave energy and marine currents (tidal stream) for the generation of electrical power. Marine currents are predictable and could be utilised without the need for barrages and the impounding of water, whilst wave energy is inherently less predictable, being a consequence of wind energy. The conversion of these resources into sustainable electrical power offers immense opportunities to nations endowed with such resources and this work is partially aimed at addressing such prospects. The research presented conveys the current status of wave and marine current energy conversion technologies addressing issues related to their infancy (only a handful being at the commercial prototype stage) as compared to others such offshore wind. The work establishes a step-by-step approach that could be used in technology and project development, depicting results based on experimental and field observations on device fundamentals, modelling approaches, project development issues. It includes analysis of the various pathways and approaches needed for technology and device or converter deployment issues. As most technology developments are currently UK based, the paper also discusses the UK's financial mechanisms available to support this area of renewable energy, highlighting the needed economic approaches in technology development phases. Examination of future prospects for wave and marine current ocean energy technologies are also discussed.
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| 24. |
- Bandara, T M W J, 1968, et al.
(författare)
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High efficiency dye-sensitized solar cell based on a novel gel polymer electrolyte containing RbI and tetrahexylammonium iodide (Hex(4)NI) salts and multi-layered photoelectrodes of TiO2 nanoparticles
- 2019
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Ingår i: Renewable & Sustainable Energy Reviews. - : Elsevier BV. - 1364-0321 .- 1879-0690. ; 103, s. 282-290
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Tidskriftsartikel (refereegranskat)abstract
- High efficiency dye sensitized solar cells (DSSCs) have been achieved using a novel polymer gel electrolyte containing RbI and tetrahexylammonium iodide (Hex(4)NI) binary salts in combination with multi-layered TiO2 photoelectrodes. Performance enhancers were incorporated to the electrolyte to improve the efficiency in the DSSCs. Varying the salt mass fraction, showed that the conductivity in the electrolyte increases with increasing amount of RbI. The highest ionic conductivity of 4.19 mS cm(-1) is exhibited by the electrolyte sample with RbI: Hex(4)NI weight ratio of 3:1 at 25 degrees C. The temperature dependence of the electrolytes shows Arrhenius behavior. It is found that the electrolyte with RbI: Hex(4)NI weight ratio of 1.06:1 is more suitable for DSSC's applications and it has a conductivity of 3.77 mS cm(-1). A colloidal suspension of P25 TiO2 nanoparticles was used to make the spin coated photo-anodes in the form of stacks of 1-6 layers. The formation of a highly uniform and porous structure is observed with increasing number of layers from scanning electron microscopy and X-ray diffraction studies revealed that the layers are predominantly anatase phase with crystallite size of 19-22 nm. The band gap was estimated to be around 3.22 eV based on UV-Visible spectroscopy and found to be decreasing slightly with increasing layer thickness. The maximum efficiency of 7.5% and an impressively high current density of 20 mA cm(-2) were observed for the 4-layer device with the new gel electrolyte based on RbI and Hex(4)NI. This study not only brings reliability and consistency to the ways of preparing well-ordered TiO2 photoanodes but also offers the possibility of low-cost practical and highly efficient quasi-solid state DSSCs.
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| 25. |
- Bao, Haiyan, et al.
(författare)
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Condition of setting surge tanks in hydropower plants - A review
- 2018
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Ingår i: Renewable & sustainable energy reviews. - : Elsevier BV. - 1364-0321 .- 1879-0690. ; 81, s. 2059-2070
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Forskningsöversikt (refereegranskat)abstract
- Hydropower plays an important role in the safe, stable and efficient operation of power systems, especially with current trends toward renewable energy systems. The total global potential of gross, technical, economic, and exploitable hydropower are still enormous in the future, and the developments of new hydropower stations (HPSs) are of great importance. For constructions of new HPSs, the condition of setting surge tanks (CSST) is crucial for various perspectives, e.g. safety, stability and economy of HPSs. In this review, the CSST are summarized and analyzed from the three aspects: regulation assurance, operation stability, and the regulation quality, with an aim of providing a reference and guidance for research and engineering applications regarding surge tanks. Upstream and downstream surge tanks in conventional HPSs and pumped storage power stations are all included. Moreover, a comprehensive comparison of CSST under different conditions is conducted. One of the main focuses of this review is on Chinese studies, for introducing many meaningful results written in Chinese to more readers all over the world.
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