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Abstract: Coalbed methane (CBM) or coal seam gas (CSG) as it is known in Australia is becoming an increasingly important source of energy around the world. Many countries such as United States, Canada, Australia and China are investing in the CSG industry. A rise in the cost of conventional natural gas and many other energy resources, along with a decline in these conventional resources and issues such as climate change have encouraged a global interest in alternative sources of energy like CSG. The estimated quantity of CSG worldwide is around 1.4×1014 m3, it is clear that coal seam gas is a significant source of energy. The first section of this paper will discuss the production size of CSG worldwide and the future of the industry. The usage of the coal bed seam for the sequestration of CO2 is also an added benefit. The reduction of CO2 released to the environment may help in the future mitigation of global warming. In addition, the re-injecting of the co-produced CO2 enhances the commercial recovery and production of CSG wells. In the second section, the impact of the CSG industry's by-products on the environment, the freshwater ecosystem and human health are analysed. The second section includes issues associated with the large volume of co-produced water with undesirable composition in the CSG industry. The management of this enormous amount of water requires cost effective technologies and methods. Many methods for dealing with water problems are discussed and analysed in this paper. [Copyright &y& Elsevier]

Renewable energy sources play a crucial role in the provision of power supply in active distribution networks. In networks that rely on renewable energy sources, it may become imperative to curtail the power generated by such units due to a variety of factors. The curtailment of renewable energy generation can be attributed to various factors such as overgeneration, voltage limitations at the network bus, and power limitations at the network line. As per the specified parameters, it is possible for the power generation of renewable units to exceed the load consumption at certain intervals throughout the operational duration. Hence, it is essential to devise a solution that mitigates the frequency and duration of power generation curtailments of renewable units. It is feasible to redistribute overgeneration of renewable energy sources from periods of excess to periods of insufficient capacity to meet demand. This study demonstrates that the provision of power to loads from the sub-distribution substation experiences a reduction in power supply and cost. It is feasible to transmit surplus power from a single bus to multiple other buses. The term used to refer to the ability to transfer power across different locations and time periods is known as spatiotemporal flexibility. The presence of data centers in distribution networks enables a reduction in costs and the frequency of power interruptions associated with renewable energy sources, through the utilization of spatiotemporal flexibility. The objective of this paper is to present a methodology for achieving temporal and spatial flexibility in data centers, with the aim of minimizing costs and curtailing the output generation of renewable energy units. Undoubtedly, this approach can also be executed by incorporating mobile batteries; however, it is noteworthy that mobile batteries entail additional costs on the network. Consequently, the implementation of the spatiotemporal flexibility approach in data centers has been adopted as a substitute for the utilization of mobile batteries. This approach, also referred to as virtual battery, effectively eliminates the costs associated with the use of mobile batteries. This study examines overgeneration of renewable units, bus voltage limitations, and line power restrictions on the standard IEEE 33-bus network. Three scenarios are considered, each involving changes in data center power in response to varying load profiles. The implementation of equitable power distribution across data centers, both in terms of temporal and spatial dimensions, as well as the adoption of flexible spatiotemporal flexibility scenario for data centers, have been observed. The findings of this study indicate that the approach employed in this paper leads to a decrease in costs and the output power of renewable units in the examined scenarios. The implementation of spatiotemporal flexibility mode has resulted in a reduction of power supply expenses ranging from 12 to 37 percent when compared to the basic case. Ultimately, the sensitivity analysis pertaining to the placement of data centers and the associated uncertainty index is presented. • Implementing a model of spatiotemporal flexibility within data centers to function as a virtual storage device. • The curtailment of power generation in renewable energy units has been executed under three different distinct circumstances. • The robust optimization method has been employed to demonstrate the uncertainties inherent in the operation problem. [ABSTRACT FROM AUTHOR]

Hydrogen, as a clean and efficient energy source, is important in achieving zero-CO 2 targets. This paper explores the potential of hydrogen geologic storage (HGS) in China for large-scale energy storage, crucial for stabilizing intermittent renewable energy sources and managing peak demand. Despite its promise, HGS faces challenges due to hydrogen's low density and viscosity, and its complex interactions with geological formations and microorganisms. This review offers a comprehensive overview of the current research status for HGS, with a particular focus on highlighting the main challenges confronting China. These difficulties and challenges primarily arise from complex geological conditions and the absence of fundamental parameters within potential reservoirs, including depleted oil/gas fields, salt caverns, and brine aquifers. Additionally, we have synthesized the current applications of machine learning (ML)as a potential solution. Key challenges are examined, such as the effects of operational parameters (e.g., cyclical injection-production and injection rates) on HGS efficiency, which can influence phenomena such as hydrogen fingering and caprock integrity. This review also looks into the insufficiently understood hydrogen-water-rock geochemical reactions under diverse temperatures and pressures, a gap that hampers the development of predictive numerical simulations and raises concerns about hydrogen leakage due to changes in porosity and permeability. Additionally, the paper addresses the limited knowledge about the metabolic mechanisms of subsurface microorganisms under extreme conditions, highlighting potential risks of hydrogen leakage and groundwater contamination. These microorganisms can metabolize hydrogen, producing gases such as CH 4 and H 2 S, which may cause steel corrosion. Furthermore, the study assesses the distribution and prospects of three primary methods for pure hydrogen storage in China, considering the current state of hydrogen development and relevant government policies. The role of ML in advancing HGS is also discussed, offering insights into future research directions. This review not only scrutinizes the scientific challenges of HGS but also underscores its potential, guiding future simulation and practical engineering applications in this field. • HGS is feasibility in China through policy examination and potential site analysis. • Geochemical and microbial reactions jeopardize to reservoir integrity and H 2 quality. • Elucidating the present application and future prospective for ML in HGS. • Summarizing the key challenges associated with achieving large-scale HGS. [ABSTRACT FROM AUTHOR]

This paper is the editorial for the virtual special issue (VSI) of Renewable and Sustainable Energy Reviews (RSER) dedicated to three Sustainable Development of Energy Water and Environment Systems (SDEWES) Conferences held in 2022, namely: (i) the 5th South East European Conference SEESDEWES 2022 held from May 22 to 26, 2022 in Vlore, Albania; (ii) the 3rd Latin American LASDEWES 2022 held from July 24 to 28, 2022 in Sao Paulo, Brazil and (iii) the 17th SDEWES 2022 held from November 6 to 10, 2022 in Paphos, Cyprus. The VSI collected both high quality review papers and original research articles presented at these conferences, aligning with the aims and scope of RSER. Following a rigorous peer review process, seventeen articles were accepted and published. These articles explore techniques and technologies essential for advancing feasible Renewable and Sustainable Energy Systems. Spanning multidisciplinary topics, many of them address almost all the Sustainable Development Goals, offering feasible solutions for much-needed decarbonization pathways. • The VSI SDEWES 2022 presents the ready solutions for Renewable and Sustainable Energy Systems. • Five clusters for presenting the Renewable and Sustainable energy cutting edge solutions. • The positioning in the scientific context of the Renewable and Sustainable Energy Systems. • Feasible solutions for much-needed decarbonization pathways. [ABSTRACT FROM AUTHOR]

Rapid growth in population and economic development in Iran and its neighboring countries has resulted in a dramatic increase in electricity demand over the past few years. A substantial amount of electricity must be produced to meet this growing demand in this region. By installing conventional fossil power plants, using renewable energy, and interconnecting with neighboring countries, this growing demand can be accomplished. The main aim of this research is to identify prospects and challenges in the electrical sector around Iran. To this end, this paper evaluates the existing and future state of the electrical sector in Iran and its neighboring countries. Despite the fact that there is still a long way to go in terms of renewable energy in this region, there are some promising targets for the future that will allow fossil fuels to be replaced effectively. Notwithstanding this, we should point out that a number of cross-border interconnection projects are being pursued by Iran and its neighbors in order to integrate their networks and supply this growing demand. Finally, this study presents an overview of the future prospects and challenges of electricity capacity expansion, cross-border interconnections, and electricity transmission corridors in this region. The review results provide comprehensive background knowledge to all the researchers in order to investigate further into the field. This paper assists energy policy makers regarding the development of sustainable energy planning. • •In addition to providing a general overview of the geographical location, population growth, and economic indicators of Iran and its neighboring countries, this paper presents the current state of the Iranian electricity sector and its neighboring countries in light of the trends in electricity production, energy mix, price, and exports and imports. • •This paper explores the existing and future states of electricity capacity expansion in the region, specifically focusing on renewable energy sources. • •The existing and future states of cross-border electricity interconnections are examined to present a comprehensive overview of the cross-border interconnections in this region. • •This region's potential electricity transmission corridors are proposed to create the opportunity to transmit electricity across countries. [ABSTRACT FROM AUTHOR]

Integrated energy systems for multi-purpose applications are garnering increased interest in the international nuclear energy community, energy system designers and planners and decision makers in the context of deep decarbonization and net zero targets. They are expected to reduce costs and increase flexibility in operation of nuclear reactors when coupled with intermittent renewable energy sources, while also producing various commodities such as hydrogen or potable water. Adaptive solutions must be considered for each geographical area and based on the involved components of the energy system, available infrastructure, and policy in place. This paper provides an in-depth look at the strengths, weaknesses, opportunities, and threats of such systems, while addressing different aspects related to the creation of the business case for such systems including decentralization and digitalization of future energy systems. The regulatory aspects are the ones that impose challenges on the emerging hybrid energy systems and this paper highlights some of the considerations that are needed for the couplings involved, in terms of licensing procedures and safety analysis. The potential contribution of such integrated energy systems towards achieving the United Nations Sustainable Development Goals (UN SDGs) are also discussed. Concerning the stakeholders, special attention should be paid to building social acceptance and trust as this lays the foundation for successful implementation of such projects. By focusing on areas such as research and development, integration of technologies, policy support, market development, grid integration, energy storage, efficiency improvement, system modelling and simulations, significant advances in integrated/hybrid energy systems deployment can be achieved. • Role of integrated energy systems in deep decarbonization for climate change mitigation. • Strengths, weaknesses, opportunities, and threats of multigeneration energy systems. • Decarbonization, decentralization and digitalization based business models. • Integrated systems can help achieving sustainable development goals (SDG7,11,13). • Hybrid energy systems can address the challenges of intermittency and grid stability. [ABSTRACT FROM AUTHOR]

Most of the leading countries have already started mass scale electrical power production by renewable energy sources (RESs) to meet global net-zero emissions target. Harvesting RESs for electrical power generation has significant negative environmental impact which must be addressed before their full-fledged implementation. Crucial challenge of the scientist, as considered in this paper, is to supply electrical power with increasing future demand avoiding negative environmental impact as much as possible. In this context, correspondence of the adverse environmental impacts for utilizing RESs for the leading countries are focused on this paper as they are major stakeholders in this regard. State of the art, present status, prospects of various RES based power plants of the leading countries, forecasted capacity of installation, global potential, emission, required annual growth rate of utilizing RESs to meet the global net-zero emissions target, their environmental impacts considering comparative analysis of RES practices, and different government plans are discussed. It would be supportive to find out the possible sustainable solution to meet the future electricity demand with minimizing adverse environmental impact. [Display omitted] • Prospects of harvesting different RESs for electrical power generation are pointed out. • Analysis of environmental impacts for utilizing RESs is performed. • Forecast with time series analysis is illustrated to find the gap between the current progress and target. • Correspondence among the current installation, prospect, challenge, target, and forecast are depicted. [ABSTRACT FROM AUTHOR]

In recent years, the severe environmental degradation and high levels of fossil fuel consumption linked to conventional ship energy systems have drawn attention to the advancement of alternative ship energy systems. Consequently, ship energy systems based on the use of an electrical microgrid are coming to the fore as an increasingly popular alternative solution. However, managing the energy flows within a shipboard microgrid can be highly challenging due to the multiple energy sources (including renewable energy sources) and types of loads involved. Additionally, the integration of an energy storage system has been identified as an effective solution for improving the reliability of shipboard power systems, pointing out the important role of energy storage systems in maritime microgrids and their potential to enhance the energy management process. As such, effective energy management strategies are necessary to optimize performance and ensure that the vessel's energy demands are met while minimizing fuel consumption and reducing cost and environmental impacts. This paper presents a comprehensive review of such strategies and methods recently presented in the literature associated with energy management in shipboard microgrids integrating energy storage systems and examine the different techniques that can be utilized to achieve optimal system performance. Moreover, the paper also sheds light on the future challenges and perspectives imposed by the modern shipboard microgrids operation on the energy/power management of these systems. The aim of this paper is to provide a helpful guideline for researchers and engineers conducting research in the field of electrically powered ships. [Display omitted] • A comprehensive review of EMS for electrical and hybrid ship is presented. • A comprehensive review of ESS which can be used in such ships is presented. • Technologies of ESS and their suitability to ships are discussed and commented. • Future challenges and perspectives imposed by modern SMG operation are presented. [ABSTRACT FROM AUTHOR]

Australia has significant offshore wind resources that can support ever-increasing power demand and hence provide a long-term contribution to the net-zero target by 2050. Although some offshore wind farm projects are proposed in Australia, the industry is not mature enough to justify the benefits and display economic opportunities. More specifically, the techno-economic analysis of offshore wind energy has not been systematically mapped in Australia. Therefore, the investigation of the spatial variation of technical feasibility and economic potential of offshore wind is vital to identify the potential regions and to develop strategies for future offshore wind farm developments in Australia. This paper presents detailed mappings of the techno-economic potential of offshore wind energy in Victoria-Tasmania's exclusive economic zone. Offshore wind energy resources are assessed in the paper in terms of energy availability and variability and the feasibility of various offshore wind technologies is investigated, including turbines, foundation types and transmission topologies. In addition, the high-fidelity life-cycle cost models and two innovative evaluation matrices are developed to assess the economic potential of offshore energy farms in South-eastern Australia. The impact of local power system regulation costs and future carbon prices on the viability of offshore wind is also investigated in this paper. It is concluded that the detailed mapping approach and analysis in the paper can provide a systematic tool for industry partners, investors and policymakers at the pre-planning stage of developing offshore renewable energy systems. • The technical feasibility of offshore wind is mapped under various constraints. • The novel LACE and high-fidelity LCC assessment models are developed. • The techno-economic potential is systemically mapped in South-eastern Australia. • The impacts of electricity market regulation and future carbon prices are studied. [ABSTRACT FROM AUTHOR]

With renewable energy sources projected to become the dominant source of electricity, hydrogen has emerged as a crucial energy carrier to mitigate their intermittency issues. Water electrolysis is the most developed alternative to generate green hydrogen so far. However, in the past two decades steam electrolysis has attracted increasing interest and aims to become a key player in the portfolio of electrolytic hydrogen. In practice, steam electrolysis follows two distinct operational approaches: Solid Oxide Electrolysis Cell (SOEC) and Proton Exchange Membrane (PEM) at high temperature. For both technologies, this work analyses critical cell components outlining material characteristics and degradation issues. The influence of operational conditions on the performance and cell durability of both technologies is thoroughly reviewed. The analytical comparison of the two electrolysis alternatives underscores their distinct advantages and drawbacks, highlighting their niche of applications: SOECs thrive in high temperature industries like steel production and nuclear power plants whereas PEM steam electrolysis suits lower temperature applications such as textile and paper. Being PEM steam electrolysis less explored, this work ends up by suggesting research lines in the domain of i) cell components (membranes, catalysts and gas diffusion layers) to optimize and scale the technology, ii) integration strategies with renewable energies and iii) use of seawater as feedstock for green hydrogen production. • Advances in steam electrolysis for hydrogen production with SOEC and PEM cells. • Demonstrative SOEC systems have been successfully integrated in different industries. • PEM steam electrolysis technology is still at laboratory scale. • Scaling up of PEM steam electrolysis needs of novel membranes and better catalysts. [ABSTRACT FROM AUTHOR]

One crucial requirement for power systems is the necessity to enhance flexibility, enabling the seamless integration of a substantial amount of renewable energy generation. While flexibility holds significance in current power systems, the escalating penetration of renewable energy resources emphasizes an ongoing and growing need for flexibility in the future, given the intermittent nature of these energy sources. To address the crucial aspects of decarbonization for sustainable development and recognizing decentralization as a strategy for grid development, this research concentrates on flexibility in the context of microgrids. Diverging from many existing review papers that explore flexibility in the broader power system context, this study pioneers an investigation from the local energy system's perspective, introducing a novel classification of flexibility resources. The exploration begins with elucidating various concepts and definitions of flexibility. Subsequently, flexibility resources available to microgrids are systematically categorized based on the operation modes. A comprehensive review of conducted research follows, highlighting diverse categories and emphasizing primary flexibility resources. Special attention is given to recent concepts such as power-to-gas/hydrogen conversion, using electrolyzers as flexible loads for (green) hydrogen production, and various storage devices, as they offer flexibility during both off-grid and grid-connected operation modes in microgrids. Furthermore, a comparative analysis is undertaken, detailing the objective function(s) and flexibility resources employed in different research studies. To quantify flexibility, the latest metrics are categorized and explained. The study concludes by presenting suggestions for future research directions and summarizing key findings. [Display omitted] • Reviewing the concept of flexibility from the point of view of microgrids. • Novel classification for flexibility resources based on microgrids operating modes. • Special attention to recent technologies such as power-to-gas/hydrogen. • A comparative analysis, detailing the objective function(s) and flexibility resources. • Categorization and explanation of the latest flexibility metrics and their application. [ABSTRACT FROM AUTHOR]

The integration of stochastic distributed energy sources and loads has introduced unprecedented levels of uncertainty in power systems. This uncertainty poses significant challenges to power system stability due to the resulting variability of power flows and system inertia. This review provides a comprehensive overview of the methods proposed in the scientific literature for assessing the small-signal stability of power systems under uncertain conditions. The review critically examines the key features, advantages and disadvantages of each method presented and identifies relevant research gaps in the field, suggesting potential future research directions. [Display omitted] • Power systems are increasingly affected by uncertainties. • A review on the methods to evaluate uncertain small-signal stability is lacking. • An extensive collection of papers on uncertain small-signal stability is provided. • The advantages, disadvantages and features of the presented methods are presented. • Existing research gaps are highlighted and future research directions are suggested. [ABSTRACT FROM AUTHOR]

This paper presents a systematic literature review of urban wind energy harnessing in built environments. In line to foster decarbonisation in urban areas of tropical countries with decentralised renewable energy technologies, such as small wind turbines in buildings, this research has been carried out. To provide a comprehensive foundation on the topic, urban wind assessment research for various purposes was reviewed, where 48 studies for energy harnessing purposes were classified by country, region and methods. The methodologies are divided into six stages, of which environmental assessment and resilience analysis are scarce. Due to tropical countries being exposed to atmospheric events that historically cause human and material losses, potential future research could be made in line with resilience analysis through metrics that are key to the proper mass deployment of building-integrated wind turbine systems. Of 66 methods for wind prospecting, the most used are on-site measurement, computational fluid dynamics simulation and numerical climate prediction, which represent 49 %, 22 % and 17 %, respectively. Other decision-making techniques are presented with the aim of addressing new ways in strategic planning to promote the use of this technology. [Display omitted] • Urban wind energy research does not deem energy resilience analysis. • Few evaluations of urban wind energy have been carried out in the tropics. • Hurricanes represent a hazard for building-integrated wind turbines. • On-site measurement and CFD simulation are the most adopted methods. [ABSTRACT FROM AUTHOR]

Under the banner of the United Nations' Sustainable Development Goal 7 (SDG 7), governments, industry, and civil society organisations have supported many energy access projects since 2015. Notably, funding and investments allotted to renewable energy are regarded not only to provide 'energy for all' but also support the delivery of other SDGs related to climate change, food security, health, and poverty reduction, among others. With less than 10 years left to meet the SDG 7 targets, it is timely to take stock and examine how the provision of access to energy is driving development initiatives, impacting local communities, and influencing governance processes. This paper offers a critical review and analysis of the impact of access to energy projects based on empirical work from eight country case studies across Africa, Asia, and Latin America. It interrogates how these projects contribute towards achieving SDG 7 and other sustainable development goals, highlights challenges, and then draws lessons for research, policy, and development practice. To advance SDGs, it recommends action in four areas: addressing rural-urban disparities, ensuring that energy is linked to sustainable outcomes, balancing top-down and bottom-up agendas, and appraising implications of techno-economic factors. [Display omitted] • Energy access has been constrained by multiple factors outside of policy decisions. • Governance decisions have overlooked local actors who are key to project sustainability. • Improved efficiency is more vital to energy security and access than increased generation. • Alignment between policies, governance processes, and institutional commitments is crucial. [ABSTRACT FROM AUTHOR]

Despite a substantial potential of renewable energy sources, the current energy supply system in Iran relies almost entirely on fossil fuel resources. It has imposed significant financial burden on the country and has led to considerable GHG emissions. Moreover, the country is confronting several challenges for harnessing alternative clean energy sources and promoting rational energy policies over the recent decades. To probe the root cause of these problems, this paper first provides an overview on the previous energy planning attempts in Iran. It shows that adequate commitment to a long-term energy planning could have meaningfully prevented these serious challenges. However, the previous studies have had some limitations in terms of employing appropriate planning tools, comprehensive evaluations, and scenarios definition and ranking. This paper thus proposes a power planning framework to assess the sustainability of future electricity scenarios for the period 2015–2050. MESSAGE, a systems engineering optimization model, is employed to evaluate the potential impacts of transitioning to a low-carbon electricity supply system. Using a combined AHP-TOPSIS method, the scenarios are then ranked based on 18 different techno-economic, environmental, and social dimensions of sustainability. The results indicate that scenario Cl_32, in which the share of non-hydro clean energy for electricity generation reaches 32%, is ranked best. • Iran's energy planning studies are reviewed. • A suitable link between energy planning and policy making is necessary for Iran. • A framework for sustainable development of the power sector is proposed. • MCDM is used to assess the sustainability of different scenarios. • The share of non-hydro clean energy technologies should increase up to 32% by 2050. [ABSTRACT FROM AUTHOR]

Zero energy buildings (ZEBs) are targeted by several developed countries around the world which consequently promotes the progress toward achieving ZEBs. The concept of ZEBs is, however, uncommon in developing economies such as Oman. In 2011, The Research Council of Oman has announced a competition to design, construct and operate buildings that embrace sustainability principles. The first five eco-friendly buildings were designed and constructed by academic institutions in different climatic conditions of Oman. This project has significantly contributed toward raising awareness of energy efficiency and renewable energy systems in buildings. This paper outlines the design of sustainable energy systems of one of these five buildings. The ZEB prototype is located at the Sultan Qaboos University campus in Muscat, which is an extremely hot climate as classified by the ASHRAE Standard 169-2013. The ZEB building was designed with full manipulation of natural energy. This paper also reports the experimental results of its one year of operation. The results showed that energy use intensity (EUI) of 103 kWh/m2 was achieved by this building. The building was less than 3% from achieving its net-zero energy source/site/emissions status. Nonetheless, it was able to achieve a positive energy cost status because of the financial credits received from the exported energy, which is subjected to high cost feed-in tariffs. When grid interaction was considered, 40% of the building load was met by site generation. For 33% of the time, this building was independent of the electrical grid, which is comparable to other net-zero energy buildings located in other climates. While several experimental studies for ZEB performance have been described in literature for heating dominated climates, very few experimental studies have been published for cooling dominated climates. Hence, this study aims to fill the gap in the knowledge of energy performance of ZEBs located in this region. • The design of sustainable energy systems for ZEB in a hot climate is described. • ZEB is feasible in cooling dominated climate. • Experimental result for one year of operation for a prototype ZEB is described. • For 33% of the time, the building was independent of the electrical grid. 40% of the building load was met by the site generation. [ABSTRACT FROM AUTHOR]

Abstract Using different types of renewable energy sources considering their uncertainties causes numerous challenges for minimizing the operation cost and maximizing the reliability of system. Hence, stochastic programming is an essential tool to consider the system uncertainties. This paper presents a day-ahead energy management system to decrease the operation cost and increase the reliability of a Microgrid considering a number of challenges for supporting electrical and thermal loads. In the proposed method, micro-CHP units, renewable energy sources, auxiliary boiler and energy storage system are all responsible for supplying the electrical and thermal loads. The problem is formulated as a multi-objective optimization problem. Moreover, the influence of considering the electrical energy storage system as a non-ideal battery with charge/discharge efficiency less than 1 is investigated. Also, demand response programs are provided based on load shifting contracts to consumers. A scenario-based approach is used to cover the uncertainties of renewable energy sources, market price and electrical load. Besides, this paper considers both islanding and grid-connected modes of Microgrid and investigates the influence of demand side management on operation cost and reliability in both modes. The capability of the proposed algorithm is analyzed by simulation results of a 3-feeder Microgrid. Highlights • Stochastic model is proposed for covering the uncertainties of variables. • The effect of micro-combined heat and power units on operation cost are considered. • The effect of storage system on operation cost and reliability index are considered. • Operation cost and reliability index are considered as objective functions. • Presenting a new mathematical method for implementing direct load control programs. [ABSTRACT FROM AUTHOR]

Abstract In this research, we aim at exploring the influence of renewables on industrial production (Ip) in the US by following continuous wavelet coherence and partial continuous wavelet coherence analyses. To this end, we observed the co-movements between, biofuels and Ip, solar and Ip, wind and Ip, geothermal and Ip, wood and Ip, and, waste and Ip in the US for the monthly period from January 1989 to November 2016. The primary motivations behind this research are twofold. Firstly, it attempts to reach the co-movements, if exists, between renewables' consumption and industrial production by following time domain and frequency domain analyses. Secondly, it aims at observing the potential co-movements between renewable energy sources (geothermal, solar, wind, biofuels, wood, and, waste) and Ip by adding some control variables (fossil fuels, total biomass etc.) into the wavelet models to understand clearly the responses of the industrial production to the impulses in renewables in both short term and long term periods. The paper hence eventually reveals significant effects of geothermal, wind, solar, biofuels, wood, and, waste on US industrial production in short term cycles and long term cycles. Thereby, following this paper's results of continuous wavelet analyses which depict the impact of renewables on US economy at 1–3-year frequency and 3–8-year frequency for the time period from January 1989 to November 2016, one might provide policy makers with relevant current and future efficient renewables' energy policy for the US and other countries which have similar structures with the US. Highlights • Explores the influence of renewables on industrial production (Ip) in the US. • Employs continuous wavelet coherence and partial continuous wavelet coherence analyses. • Observes the co-movements between, biofuels-Ip, solar-Ip, wind-Ip, geothermal-Ip, wood-Ip, and, waste-Ip pairs. • Reaches strong co-movements between renewables and Ip both in short run and in the long run. • Can claim that renewable energy sources can influence positively the US industrial production. [ABSTRACT FROM AUTHOR]

Abstract As a result of the global decarbonisation policy, the increased penetration of RES (Renewable Energy Sources) into the electrical power system is introducing some serious technical challenges, one of the most serious being to maintain voltage profiles within acceptable/allowable limits. The unpredictable generation of a considerable share of the renewable energy can result in voltage deviations that system-network operators are not able to control effectively. At the present stage of the technology, the power electronic converters that are applied for most of the RES are used as a kind of adapter that ensures optimal RES operation and transmits the active power to the grid. But each of these converters, together with an energy source (or sink), inherently also exhibits the characteristics of a FACTS device. As a result, there should be no hindrance to applying the theories for enhanced EPS (Electric Power System) stability limits, developed for FACTS devices, also for RES converters. Many of the problems that are caused in an EPS by the large share of RES could be solved by the RES itself, also at the system level, if properly controlled and IT connected to each other and to the system operator. In this context, the present paper reviews the impact of FACTS devices on the voltage stability with methods based on the calculation of PV curves. An analytical, in-depth approach can clearly demonstrate the theoretical feasibility of FACTS devices for voltage-stability enhancement. The paper presents such an approach for CSC, SSSC, SVC and STATCOM, based on an analytical calculation of the area between the PV curves and the voltage margins in a PV diagram. The basic contribution of the paper is a theoretical explanation of the suitability of various FACTS devices for maintaining an optimal voltage profile, taking into account any variation of a device parameter. Highlights • Growth of renewable energy sources can significantly influence voltage stability. • Influence of FACTS devices on voltage stability in electric power system is shown. • A new idea named PV area criteria for voltage stability is presented. • PV area criterion estimates suitability of FACTS for voltage-stability enhancement. [ABSTRACT FROM AUTHOR]

Abstract While auctions are becoming increasingly popular for tendering renewable energy projects to private developers in Africa, their specific project risk implications are not yet fully understood. This paper identifies project risks arising from two types of auction schemes. It compares an approach where the government pre-selects the sites for future renewable energy plants in Zambia's Scaling Solar initiative to one where project developers choose, secure and conduct due diligence on their sites before bidding in South Africa's Africa's Renewable Energy Independent Power Producers Procurement Programme (REI4P). Semi-structured interviews with developers who have participated in both schemes reveal notably different risk profiles. Despite contrary intentions, site-specific risks have been perceived as the highest overall project risk in the government-led site selection process in Zambia. Specifically, site-specific risks were driven by several severe technical issues such as geotechnical, grid connection and solar irradiation uncertainties. In contrast, in South Africa's developer-led site selection process, site-specific risks have been reported to be important, but less pronounced, and more evenly distributed among technical, economic, legal, permitting and social risk factors. This paper recommends an auction design which minimises project risks for all stakeholders. Where governments pre-select sites, closely consulting the private sector is advisable prior to bidding to identify and mitigate technical and other site-specific risks. Highlights • Explores risk impact of two site selection & preparation strategies for solar PV project procurement in sub-Saharan Africa. • The widely used strategy in the region is for a government institution or utility to select and prepare the project site. • The second strategy is where the private sector developers are responsible for selecting & preparing the site before bidding. • We find that a government-led site selection strategy can lead to increase risks, costs and timelines if poorly executed. • It is argued that more private sector involvement in the site selection & preparation process might reduce these risks. [ABSTRACT FROM AUTHOR]

Abstract Along with the advent of restructuring in power systems, considerable integration of renewable energy resources has motivated the transition of traditional distribution networks (DNs) toward new active ones. In the meanwhile, rapid technology advances have provided great potentials for future bulk utilization of generation units as well as the energy storage (ES) systems in the distribution section. This paper aims to present a comprehensive review of recent advancements in the operation of active distribution systems (ADSs) from the viewpoint of operational time-hierarchy. To be more specific, this time-hierarchy consists of two stages, and at the first stage of this time-hierarchy, four major economic factors, by which the operation of traditional passive DNs is evolved to new active DNs, are described. Then the second stage of the time-hierarchy refers to technical management and power quality correction of ADSs in terms of static, dynamic and transient periods. In the end, some required modeling and control developments for the optimal operation of ADSs are discussed. As opposed to previous review papers, potential applications of devices in the ADS are investigated considering their operational time-intervals. Since some of the compensating devices, storage units and generating sources may have different applications regarding the time scale of their utilization, this paper considers real scenario system operations in which components of the network are firstly scheduled for the specified period ahead; then their deviations of operating status from reference points are modified during three time-intervals covering static, dynamic and transient periods. Highlights • A survey of operational methods of active distribution systems (ADSs) is presented. • A two-stage time-hierarchy methodology is adopted to categorize recent research. • Day-ahead economic management of ADSs is explored in the first stage. • Static, dynamic and transient operations of ADSs are studied in the second stage. • Modeling and control needs of ADS economic/technical operation are reviewed. [ABSTRACT FROM AUTHOR]

Abstract The demand for reduction of greenhouse gases, the need for a decreased dependence on fossil fuel, and the increasing penetration of the renewable energy sources are changing the world's electrical energy production. The island of Crete in Greece possesses great potential when it comes to wind and solar energy. Currently, a large amount of wind energy is often being curtailed in Crete, due to the technical minima of the existing thermal units, the inherent fluctuating power output of the wind turbines and the electricity demand profile. Electrical energy storage is recognized as an underpinning technology to have great potential in overcoming these challenges. There are many different ways to store the surplus energy and convert it back to electrical energy when it is needed. The aim of the present paper is the investigation of the role that energy storage can play in the further development of renewable energy sources in non-interconnected islands via considering the energy storage technologies of compressed air energy storage, pumped hydroelectric storage and sodium – sulfur batteries. This paper examines the solution of electrical energy storage in curtailment exploitation. A review over the above energy storage technologies is carried out and a comparative analysis is performed for the case study of Crete. Each storage technology is techno-economically evaluated using actual data. Finally, a parallel comparison of the examined storage systems' levelized cost of energy is presented and conclusions are drawn. The compressed air energy storage system appears to be more favorable, having the lowest levelized cost of energy of the examined systems studied at 0.21 €/kWh, while contributing 105.59 GWh of electrical energy to the island's grid per year. For the examined case study, compressed air energy storage system appears to be almost 20% and 50% cheaper in terms of levelized cost of energy in comparison with pumped hydro storage and batteries respectively. Highlights • Review on compressed air energy storage, pumped hydroelectric storage and sodium – sulfur batteries. • Techno-economic comparative analysis of energy storage technologies for the case study of Crete. • Comparative findings on levelized cost of energy of different storage technologies. [ABSTRACT FROM AUTHOR]

Abstract Due to the massive entrance of new renewable energies such as wind or solar, hydraulic turbines have to work far from its designed point and withstanding multiple transients, such as starts and stops, that shorten the useful life of the machine and cause fatigue damages. The present paper reviews the complex problem of fatigue in Francis turbines particularly focused on the experimental data available for static and dynamic stresses. For this purpose, many researches, which include different Francis turbines covering a wide range of design head and power, have been considered. The experimental stresses characteristics measured with strain gauges installed on the turbine runner and obtained from previous works have been analyzed for the different operating conditions and transient states occurring in the normal life of actual Francis units. The actual computational capabilities and techniques typically used to estimate such stresses have been discussed in detail. Potential future techniques to simplify complex strain measurements on the turbine runner, computational and statistical methods to estimate turbine stresses are reviewed in this paper. Finally, the relative damage of the different operating conditions and useful life estimation of the turbine, based on past strain measurements of the runner, are addressed. Highlights • This paper reviews the complexity of fatigue life estimation of Francis turbines in all the involved steps. • Data and conclusions of different manufacturers and researchers are summarized and compared. • The main characteristics of stresses have been identified and the capabilities of numerical techniques discussed. • Potential future experimental and numerical techniques to simplify actual experimental measurements are shown. • Existing data of relative damages has been compared. Probabilistic fatigue models in hydro turbines have been addressed. [ABSTRACT FROM AUTHOR]

Abstract African countries are in a unique position to reap the socio-economic and environmental benefits of renewable resources as a means for meeting increasing energy demand in a sustainable way. A critical obstacle for the deployment of renewable energy technologies in Africa is the difficulty of attracting sufficient and affordable finance. This paper compares the impact of financial conditions on the cost of electricity generation across six renewable and three fossil-based technologies in 46 African countries. The results show large cost variations and highlight the extent to which renewables are disadvantaged by current financial practices. The energy-economy-environment model TIAM-ECN is used to show how lowering financing costs results in a much higher deployment of renewables. For example, solar PV could account for 10–15% of total electricity generation by 2050, even without explicit climate policy, thanks to financial de-risking programmes. The results demonstrate that changes in financing schemes could outweigh the impact of technology learning. This paper also demonstrates that, once ambitious climate policies are in place, reducing financing costs for renewables could be an efficient way to lower greenhouse gas emissions. Financial de-risking is thus a key ingredient for unlocking the renewable energy potential in Africa. Highlights • We show how renewables are disadvantaged by today's financial practices in Africa. • We show how lower financing costs result in a higher deployment of renewables. • PV can account for 10–15% of electricity generation by 2050 without climate policy. • Changes in financing schemes could outweigh the impact of technology learning. • Financial de-risking is key for unlocking the renewable energy potential in Africa. [ABSTRACT FROM AUTHOR]

Abstract Increasing cooling demands in the built environment call for innovative technical solutions and systems for application in buildings. Cooling loads represent an important share of the total energy consumption in warm climates, especially in commercial and office buildings. Moreover, mechanical systems will still be needed in most cases to cope with cooling loads, even after considering passive cooling strategies in the design of the building and its façade. Solar cooling technologies present interesting assets, being based on environmentally friendly cooling processes, driven by solar and thus renewable energy. However, their application in the built environment remains greatly limited. This paper assesses several solar cooling technologies in terms of their potential for façade integration; aiming to promote widespread application in buildings throughout the development of integrated architectural façade products. The assessment is based on a state-of-the-art review and discussion of key attributes for façade integration of selected technologies; and a qualitative evaluation of their suitability to respond to main product related barriers for the integration of building services identified in an earlier work by the authors. The cooling principles behind the operation of the assessed technologies have been extensively presented in the literature, so this paper focuses exclusively on key aspects to overcome barriers related to the technical feasibility, physical integration, durability, performance, and aesthetics of future integrated concepts. Results show that the suitability of the assessed technologies varies according to each particular barrier. Hence, no technology currently fits all required aspects. Nonetheless, the use of thermoelectric modules and compact units based on absorption technologies are regarded as the most promising for the development of either integral building components, or modular plug & play systems for façade integration. In any case, this is heavily conditioned to further efforts and explorations in the field to overcome identified challenges and knowledge gaps. Highlights • No assessed technology currently fits all required aspects for façade integration. • Technologies' suitability varies according to each façade integration barrier. • Current potential was mapped identifying bottlenecks and drafting recommendations. • Thermoelectrics and compact units based on absorption technologies are promising. • Adsorption/solid desiccant developments should aim to partial façade integration. [ABSTRACT FROM AUTHOR]

Abstract Green and renewable bio-diesel prepared from oils catalytic hydrodeoxygenation (HDO) will have a great impact on clean energy structure and industrial application. The core issue of catalytic oils HDO research is still the development of catalysts with high performance, and it has become the research focus of researchers in recent years. The bio-diesel after deoxygenationis similar to petroleum fuel in composition, which has better fuelproperties because of its higher cetane number, higher energy density, and very low sulfur content. Therefore, the prepared bio-diesel can be employed directly in fuel industry. In order to ensure that the catalyst has superior deoxidization performances, it should have good "H-H" dissociation ability, "C-O" and "C=O" adsorption and activation abilities. To obtain the expected products, feasible production processes, and suitable catalyst systems are needed. In this paper, the status and reaction system of oil HDO conversion in recent years are reviewed, and the catalytic performances of the corresponding catalyst in the oil HDO reaction is described in detail. In addition, this review also involed the effects of support, promoters, interaction between active components and support on the HDO activity and selectivity, and detailed information about the reaction mechanism. The HDO performances of the corresponding catalyst can be effectively improved by optimizing the active components and controlling the properties of the support. The catalyst used into the HDO reaction is mainly concentrated on the supported catalyst. In addition, the choice of the support is based on the prepared catalyst with the best physical and chemical properties. What's more, ensuring the prepared catalyst has simple deoxidation route, suitable acid strength, high "C-O" hydrogenolysis activity and low carbon deposition performances. The selection of the metal active component mainly depends on the model compound, owing to the deoxidization pathway of the model compound is mainly determined by the active center. The reaction pathway mainly contains hydrolysis, HDO, cracking, hydrogenation, decarbonylation, and decarboxylation reaction. In addition, several outlooks on the development of catalyst with high performance, the future research, and the development direction of bio-diesel produced by oils HDO reaction are also addressed in this paper. Highlights • Green and renewable bio-diesel can be prepared from oils catalytic hydrodeoxygenation (HDO). • Noble metal catalysts and non noble metal catalysts each have advantages in oil hydrodeoxygenation. • The development of new catalyst is beneficial to hydrodeoxygenation of oils to produce bio-diesel. • Deep excavation of hydrodeoxygenation mechanism is conducive to prepare catalysts with superior performance. [ABSTRACT FROM AUTHOR]

Abstract How can leaders successfully craft energy or climate policy to support an initiative that citizens oppose? This paper considers this challenge from a change management perspective applied to public governance. It first draws on change management theory to develop a framework for altering mass public perspectives. The framework consists of four phases: i) problematizing the issue, ii) laying a foundation for change, iii) reshaping perspectives, and iv) entrenching support. Drawing from the insights gleaned from the establishment of Japan's nuclear power program, the paper further argues that in order to succeed in mass perceptual change, policymakers must first clearly understand the contextual environment in which the policy is being formulated. In doing so, policymakers will be better able to customize policy design to appeal to stakeholder perceptions and sentiments. Although the context of this paper is the perceptual modification of public opinion to support nuclear power, the authors suggest that the same framework can be applied to perceptual modification of any policy that the general public might be opposed to. In the energy sector, this could apply to fostering a transition to renewable energy as easily as it applies to nurturing nuclear power development. However, the Japanese case puts forth a caveat in this regard, there is evidence that the mindsets of the Japanese policymakers were predisposed to advocacy of nuclear power and once policymakers commit to a technological trajectory, it is hard to engender a change of course. Therefore, the article concludes by speculating on how the perceptions of policymakers might be similarly altered through efforts from the alternative energy sector to foster policy change. Highlights • 4 elements frame pace, scale and scope of technological change. • The elements are change incentives, alternatives, stakeholder perceptions & contextual influence. • Altering public perception requires 4 strategic steps. • 4 Steps: i) problematize, ii) lay a foundation for change, iii) reshape perceptions, and iv) entrench. • The paper applies this to explain rise of Japan's nuclear power industry. [ABSTRACT FROM AUTHOR]

Abstract Renewable energy targets announced in 2014 present an opportunity to reform Indonesia's electricity sector which is dominated by fossil fuels. In this paper we discuss Indonesia's current renewable energy policies and future outlook for achieving the targets. This paper serves as a literature review of Indonesia's changing energy policy landscape, as part of a broader research investigating renewable energy targets and the role of the private sector. Despite Indonesia's wealth of renewable energy resources, numerous studies have identified multiple constraints to the development of renewable energy, including geographical, institutional and investment factors. Influential groups are calling for the Indonesian Government to put in place a clear policy framework that facilitates private sector investment. Therefore, interventions to facilitate investment in energy infrastructure in Indonesia must address the monopolised power market system that oversees a changing, complex malaise of electricity pricing regulations which make investment risky and uncertain. This study will enrich the existing literature on renewable energy policy which emphasises the importance of engaging the private sector. It is based on a rigorous qualitative assessment of Indonesia's changing policy that affects the progress of the renewable energy targets. The lessons from Indonesia's experience may provide insights for policymakers notably in developing countries.Keywords: energy in Indonesia, private sector investment, renewable energy Highlights • Indonesia's renewable energy targets show awareness of the need for renewable energy to solve the energy trilemma challenge. • The targets represent forward thinking policy that moves from the abstract to measurable targets. • Private sector participation is imperative to address today's under investmentin Indonesia's electricity infrastructure. • Indonesia needs to reinforce its commitment to renewable energy to resolve constraints impeding private sector investment. • Indonesia needs to embark on electricity sector reform that encompasses decarbonisation as part of its strategy. [ABSTRACT FROM AUTHOR]

Abstract Increasing energy demand, high energy cost and global warming issues require energy-intensive industries to make sincere efforts to improve energy efficiency. The energy consumption data available for different industries suggests that pulp and paper industry accounts for a significant share. Amongst various procedures to make paper, Kraft recovery process is majorly employed that yields weak but lignin-rich black liquor as a byproduct. Black liquor is one of the emerging biomass energy resources with a strong potential to be used as a biofuel for generating steam/energy to operate the process units, thereby, ensuring process self-sufficiency and sustainability. A Multi-Stage Evaporator (MSE) is needed to concentrate it but suffers from being the most energy consuming unit among all. This piques our interest to explore various energy reducing schemes or configurations used previously for MSE and to report previous research endeavors in the area of steady–state, dynamic modeling and simulation of such processes. It is noted that steady-state and transient behavior analysis together with an efficient controller design may significantly contribute in eliminating or troubleshooting problems to ensure both energy savings and product quality. The article highlights that such an analysis and effective solutions of developed models, due to their non-linear complex nature, are highly dependent on the nature of the algorithm employed. Attempts to design control techniques to enable efficient process control and to eliminate process uncertainties have suffered limitations not only due to inherent inefficiency of control techniques but also due to insufficient underlying knowledge or inappropriate modeling of system transience. With this perspective in mind, advanced and intelligent control techniques and their influence on process/energy transience and optimization have been reviewed. Here, we propose that it is very essential to maintain sufficient prudence in selecting an appropriate simulation, optimization and control algorithm to ensure a sustainable production. Highlights • Status of performance of energy intensive industries present worldwide in the light of current global energy scenario. • Significance and challenges of multi-stage evaporation (MSE) in paper industry. • Review of energy efficient configurations of MSE and their optimization to achieve higher energy efficiency. • Developments in the area of linear and nonlinear steady-state and transient models and control of MSE. • Challenges and limitations of available numerical techniques in solving complex nonlinear problems of such systems. [ABSTRACT FROM AUTHOR]

Abstract Adoption and sustained diffusion of renewable energy technologies (RET) in remote under-serviced communities do not follow conventional trajectories frequently requiring long gestation periods. The intent of this paper is to emphasize that these gestation periods are not dormant times but involve intense adjustment of the RET innovation to local settings. Village level biodiesel (VLB) is an RET innovation introduced into remote Indian subsistence farming communities where traditional service delivery channels either never existed or are defunct. VLB's diffusion trajectory has been benchmarked and reviewed in this paper with a focus on (1) the attributes of the innovation and (2) decision-making processes. Insights gained through this analysis indicate that promoting organizations must possess a wide range of knowledge capacities in order to be able to support a continuous adoption process. This paper does not focus on traditional and proven RET currently introduced through the private sector but on decentralized innovations, where the onus is on the promoting not-for-profit organization to develop hitherto non-existent local service delivery mechanisms and supply chains that could enhance the local economy. Empirical research for the paper was conducted as a participant observer. Highlights • Diffusion of renewable energy technologies require gestation period of 20–25 years. • Gestation phases are active periods of reinvention of the renewable energy technologies. • Village level biodiesel bootstraps economies enabling transition to sustainable livelihoods. • Biodiesel is likely to be more beneficial for livelihoods than for transportation. • Introduction and diffusion of innovations for productive livelihoods needs policy support. [ABSTRACT FROM AUTHOR]

Abstract Energy systems are quickly evolving through the development of new technologies and the emergence of new operational and market design paradigms. In particular, the global push for sustainability is driving the transition towards a pronounced redesign. In fact, renewable energy integration is occurring at a massive scale, and several other exciting developments are finding their place in modern energy systems, such as distributed energy resources, demand response, energy storage technologies, and local energy markets. In this dynamic context, the process of energy policy design and implementation has found new challenges, and in supporting this key process, expansion planning models and tools can play an essential role. For example, these models can be employed to estimate the impact of a multitude of policy instruments. Thus, there is a wide interest in these tools and a variety of such models, as evidenced by a rich literature and a fast-paced evolution of this research area. Motivated by this, this work presents a comprehensive and up-to-date review on expansion planning models and tools with emphasis on their application to energy policy analysis. In particular, this paper reviews the most significant policy instruments, with an emphasis in renewable energy integration, the optimization models that have been developed for expansion planning, and existing decision-support tools for energy policy analysis. Finally, this paper also discusses the trends in the literature and the most pressing current challenges in the development and use of expansion planning models for energy policy analysis. Highlights • Provides a comprehensive and up-to-date overview on expansion planning models. • Reviews the most significant policy instruments with an emphasis in renewable energy integration. • Describes the salient features of using expansion models on energy policy analysis. • Discusses the future trends and challenges of smart grid technologies on expansion models. [ABSTRACT FROM AUTHOR]

Abstract As a result of the increased awareness of the dangers posed by global climate changes (mainly caused by growing global energy consumption needs), the quest for clean and sustainable energy future is becoming of paramount importance. This can be largely realized via a large-scale integration of variable renewable energy sources (RESs) such as wind and solar, which have relatively low carbon footprints. In many power systems, the level of integration of such resources is dramatically increasing. However, their intermittent nature poses significant challenges in the predominantly conventional power systems that currently exist. Among others, frequency and voltage regulation issues can, for example, arise because of improperly balanced and largely uncoordinated RES supply and demand. Generally, the higher the integration level of intermittent power sources is, the higher the flexibility needs are in the system under consideration. Flexibility, in a power systems context, refers to the ability of such a system to effectively cope with unforeseen changes in operational situations, which are mainly induced by the inherent uncertainty and variability arising from the supply side, demand side or any other external factors. In the absence of appropriate flexibility mechanisms, it is increasingly difficult to manage the imbalances between generation and demand as a result of their natural variations in real-time. This paper presents an extensive and critical review of the main existing and emerging flexibility options that can be deployed in power systems to support the integration of "carbon-free" and variable power production technologies. Starting from a broader definition of flexibility, we highlight the growing importance of such flexibility in renewable-rich energy systems, and provide insights into the challenges and opportunities associated with various flexibility options provided by different technologies. Highlights • This paper presents an extensive and critical review of the main existing and emerging flexibility options. • Starting from a broader definition of flexibility, we highlight the growing importance of such flexibility. • Insights into the challenges and opportunities associated with various flexibility options are provided. • Certain barriers that may hinder their developments in the short to medium terms are also provided. [ABSTRACT FROM AUTHOR]

Abstract In recent years, China's wind power industry has developed rapidly, and become the global wind power leader. At the same time, China's wind power industry is also facing many problems and challenges. In this paper, a comprehensive assessment is presented to reveal the development history of China's wind power industry, power demand and cost, regional distribution of wind power, wind turbine manufacturers, and government incentives to wind power industry. Subsequently, future development and challenges are proposed, focusing on the challenge of wind power integration and consumption, the challenge of management and market competition mechanism, and the challenge of large-scale and rapid development. Finally, the corresponding measures are put forward. The fundamental goal of this paper is to understand the history, current situation and future challenges of China's wind power industry. Highlights • A comprehensive assessment on the development of China's wind power industry is presented. • The development history of China's wind power and energy demand are introduced. • Multi factors related to China's wind power industry are investigated. • Future challenges and corresponding measures of China's wind power industry are proposed. [ABSTRACT FROM AUTHOR]

Abstract This paper provides a comprehensive review of theories and frameworks for understanding and managing human dimensions of tidal energy. The methods for this review were: 1) the construction of an annotated bibliography of the human dimensions of marine renewable energy literature, 2) an analytical review of the core theories and frameworks found in the literature as applied to tidal energy development in the United States, and 3) an iterative process of conceptual refinement through peer review. Only 48.9% of the articles in the literature review included a theoretical underpinning, or discussed an existing framework. Of these, 42.2% were theories or frameworks that were only featured in a single paper, highlighting the need for theoretical focus within this field of study. For those theories and frameworks that had been explored in multiple articles, these theories and frameworks were grouped into nine overarching concepts: acceptance, place attachment, justice, economics, technology innovation systems, environmental assessment, strategic environmental assessment, adaptive management, and marine spatial planning (MSP). Each of these concepts were expounded on to discuss the limitations of the current research on the concept and identify promising avenues for future research. In comparing the functionality of these concepts, most have a realized capacity for understanding costs and benefits, risk and uncertainty. However less than half have a realized capacity for managing costs and benefits and risk, while less than a third have a realized capacity for managing uncertainty. This paper offers a summary table of existing theories and frameworks that could be used as a launching point for detailing a research agenda for more systematically exploring theories and frameworks for human dimensions of tidal energy. Highlights • Review of theories for understanding and managing human dimensions of tidal energy. • 48.9% of articles had a theoretical underpinning; 42.2% of these were singletons. • Most theories help understanding of costs and benefits, risk and uncertainty. • Fewer theories help manage costs and benefits, risk and uncertainty. • Percentages highlight the need for theoretical focus within this field of study. [ABSTRACT FROM AUTHOR]

Abstract The requirements made on energy system models have changed during the last few decades. New challenges have arisen with the implementation of high shares of Renewable Energies. Along with the climate goals of the Paris Agreement, the national greenhouse gas strategies of industrialized countries involve the total restructuring of their energy systems. In order to archive these climate goals, fitted and customized models are required. For that reason, this paper focuses on national energy system models that incorporate all energy sectors and can support governmental decision making processes. The reviewed models are evaluated in terms of their characteristics, like their underlying methodology, analytical approach, time horizon and transformation path analysis, spatial and temporal resolution, licensing and modeling language. These attributes are set in the context of the region and time in which they were developed in order to identify trends in modeling. Furthermore, the revealed trends are set in the context of current challenges in energy systems modeling. Combining specified research questions and specific greenhouse gas reduction strategies, this paper will help researchers and decision makers find appropriate energy system models. Highlights • Historical trends in the development of energy system models were analyzed. • Newly-developed models are more flexible in terms of spatial or temporal resolution. • Python has become the most popular programming language in energy systems modeling. [ABSTRACT FROM AUTHOR]

Abstract This paper presents a thorough review of 75 modelling tools currently used for analysing energy and electricity systems. Increased activity within model development in recent years has led to several new models and modelling capabilities, partly motivated by the need to better represent the integration of variable renewables. The purpose of this paper is to give an updated overview of currently available modelling tools, their capabilities and to serve as an aid for modellers in their process of identifying and choosing an appropriate model. A broad spectrum of modelling tools, ranging from small-scale power system analysis tools to global long-term energy models, has been assessed. Key information regarding the general logic, spatiotemporal resolution as well as the technological and economic features of the models is presented in three comprehensive tables. This information has been validated and updated by model developers or affiliated contact persons, and is state-of-the-art as of the submission date. With the available suite of modelling tools, most challenges of today's electricity system can be assessed. For a future with an increasing share of variable renewables and increasing electrification of the energy system, there are some challenges such as how to represent short-term variability in long-term studies, incorporate the effect of climate change and ensure openness and transparency in modelling studies. Highlights • We review 75 modelling tools currently used for analysing energy and electricity systems. • Updated and validated key information about the models is presented. • The paper can aid new modellers to choose an appropriate model for their purposes. [ABSTRACT FROM AUTHOR]

Abstract Growing concerns over the environmental impact of greenhouse gas (GHG) emissions, uncertainty of future fossil fuel prices, geopolitical instability, and consumer preferences are a few factors driving the development and use of biomass as a source of renewable energy. Government mandates and policy frameworks have further built consensus for effective utilization of sustainable resources for energy. As a result, biomass derived densified solid biofuels have experienced a phenomenal growth in the last decade and are expected to grow by 56% during the three decades from 2010 to 2040. Solid biomass represents the largest share of biomass used for heat and electricity generation. Biomass sources range from agricultural, municipal, and commercial wastes, to forest-litter, and energy crops. Because of the varied nature of these sources, harvesting practices and the cost of transportation, several methods have been developed to densify the biomass. The long-term viability and growth of biobased energy products hinges on the technical innovation and wider societal acceptance of these products. This paper reviews multiple biomass feedstock, processing characteristics, product properties, transportation, and storage options. The paper also discusses the economics of densifying biomass, the impacts to regions where biomass utilization is implemented, outstanding challenges, and national and global trends in biomass utilization. Highlights • Biomass feedstocks are major source for densified solid biofuels. • Environmental concerns, GHG gases emission and government mandates driving biomass utilization. • Woody and non-woody biomass represent largest share of biomass for heat and electricity generation. • Biomass feedstock type, preprocessing, densification, and transportation are critical factors for adoption of biomass for energy applications. • Technical innovation and wider societal acceptance important for growth of solid biofuels. [ABSTRACT FROM AUTHOR]

Abstract In electric power systems, there exist many diverse uncertain parameters such as loads, electricity price, wind power generation and photovoltaic power generation. In power system studies, appropriate modeling and handling of these uncertain parameters is essential. In this paper, the sources of uncertainties in power systems are described and different uncertainty handling methods in power systems are classified and reviewed in details, mentioning the merits and demerits of each method. Based on the conducted review, some directions for future research are delineated. Highlights • In electric power systems, there exist many diverse uncertain parameters. • Appropriate modeling and handling of uncertain parameters is essential. • In this paper, the sources of uncertainties in power systems are described. • Different uncertainty handling methods in power systems are classified and reviewed. • Based on the conducted review, some directions for future research are delineated. [ABSTRACT FROM AUTHOR]

Abstract In recent years, providing green and reliable energy supply to islands has appeared in the strategic plans of many countries. This paper introduces three representative island microgrids that have been built and are operating in the East China Sea. Key technologies of the island microgrids are discussed, including the analysis of island resources and load, selection of energy storage, control strategies, and energy management systems. Through analyzing their operation data for one year, this paper demonstrates the impacts of the three microgrids from the perspectives of technology, economics, and sustainability. Summarizing the experiences and insights gained from their construction and operation, this paper provides references for the future development of island microgrid projects. Highlights • Three representative island microgrids in the East China Sea are demonstrated. • Key technologies such as control technology and energy management for island microgrids are studied. • Renewable energy penetration is discussed for the design and operation of island microgrids. • The operation data for a year of the three island microgrids are analyzed from various aspects. • Experiences and insights gained from the construction and operation are presented. [ABSTRACT FROM AUTHOR]

The small island developing states of the Pacific suffer from both the high cost of fossil fuel imports and from numerous climate-related disasters. These vulnerabilities will worsen unless there is a substantial global shift away from fossil fuels towards renewable energy (RE) sources, coupled with significant improvements in energy efficiency. Apart from traditional biomass-fuelled cooking, the most substantial uses of RE in the Pacific in 2016 were hydropower in some of the hillier island countries and the thousands of household photovoltaic (PV) systems in the remoter parts of island countries. This paper considers also the prospects for grid PV, geothermal, and biofuels – all of which have good technical potential in at least some islands. Barriers to wider use of RE in the region are mostly institutional and financial, but also include opportunity costs, environmental factors, and the limited skills base in small island states. The paper examines the mixed progress since the 1990s towards overcoming these barriers. The Fiji Electricity Authority has a reasonably realistic plan to have 81% of its supply from RE by 2020, drawing on hydropower (~ 50% in 2015), biomass (including bagasse), and some solar and wind. Tonga has its Renewable Energy Roadmap with clear milestones. Several other Pacific Island countries have ambitious RE targets but some are rather vague about how they are to be achieved. [ABSTRACT FROM AUTHOR]

The liberalization of electricity markets and the development of renewable energy sources has led to new challenges for decision makers. These challenges are accompanied by an increasing uncertainty about future electricity price movements. The increasing amount of papers, which aim to model and predict electricity prices for a short period of time provided new opportunities for market participants. However, the electricity price literature seem to be very scarce on the issue of medium- to long-term price forecasting, which is mandatory for investment and political decisions. Our paper closes this gap by introducing a new approach to simulate electricity prices with hourly resolution for several months up to three years. Considering the uncertainty of future events we are able to provide probabilistic forecasts which are able to detect probabilities for price spikes even in the long-run. As market we decided to use the EPEX day-ahead electricity market for Germany and Austria. Our model extends the X-Model which mainly utilizes the sale and purchase curve for electricity day-ahead auctions. By applying our procedure we are able to give probabilities for the due to the EEG practical relevant event of six consecutive hours of negative prices. We find that using the supply and demand curve based model in the long-run yields realistic patterns for the time series of electricity prices and leads to promising results considering common error measures. [ABSTRACT FROM AUTHOR]

In the era of demands in primary energy, utilization coupled with fossil fuel is increasing in the world for the application of thermal comforts. The energy consumption and relative problem need attention to search renewable energy. Energy consumption and demand are high for air conditioning mainly in hot and humid climates. Many previous studies have confirmed that technical and economical deficits associated with conventional air conditioning systems can be eliminated using liquid desiccant air conditioning (LDAC) technologies. This paper reviews studies on liquid desiccant air conditioning. The objective of this paper is to use liquid desiccant based air conditioning regenerated by renewable energy. Thermo-physical properties liquid desiccants are first realized to use as air conditioning. Regeneration temperature of saline salt and newly organic compound viz. Glycol-water solution desiccants is in a decreasing order of LiBr, LiCl, CaCl 2 , LiCl-CaCl 2 mixture and glycol water solution, while the dehumidification is in an increasing order of CaCl 2 , LiCl-CaCl 2 mixture, LiCl, LiBr and Glycol-water solution respectively. Main problems using liquid desiccant saline salt solutions are corrosiveness and crystallization and these can be resolved by using glycol water solutions and ionic liquids (ILs) which are attracting attention due to low regenerative temperature, non-corrosiveness, and higher dehumidification but these are volatile, viscous, and costly than the saline salt solutions. [ABSTRACT FROM AUTHOR]

As the demand for renewable energy continues to rise, the significance of electrocatalysis research for hydrogen production has also increased. To explore the developmental trends in this field, a scientometric-assisted review was conducted using clustering analysis of keywords from 43,564 papers published between 2013 and 2022. The results of the study demonstrate a globally diverse research landscape, with contributions from Asia, Europe, North America, and the Middle East. China emerges as the most prolific contributor, with consistent growth in research productivity over the past decade. The USA, South Korea, India, and Germany were among the top five leading countries in electrocatalysis research. Singapore, USA, Australia, Saudi Arabia, and Germany lead research impact, measured by total citations per total paper. China has the highest collaboration in electrocatalysis research, with collaborations with the USA, Australia, Singapore, Saudi Arabia, Japan, the UK, Germany, Canada, Korea, and India. Importantly, the study reveals six clusters of electrocatalysis research, with different author keywords, each covering a range of topics and materials. The implications of each of the six clusters in electrocatalysis are examined critically. This study offers valuable insights for researchers, policymakers, and funding organizations in making critical decisions by identifying the main themes and trends in hydrogen evolution through electrocatalysis research. • To explore the developmental trends in this field, a scientometric-assisted review was conducted on renewable energy • The results of the study demonstrate a globally diverse research landscape. • This study offers valuable insights in hydrogen evolution through electrocatalysis research. [ABSTRACT FROM AUTHOR]

Wind energy is a promising and efficient renewable energy source for electrical energy production. Globally, there has been a significant increase in the development of wind energy conversion systems (WECS). The world is interested in grid codes applying for facing various problems because of large capacity WECS integration with the grid, including the stability and reliability of electrical grid and power quality. Low voltage ride through (LVRT) capability is an important requirement of grid codes. LVRT means that the wind turbine is still connected to the grid during grid voltage sags. This is essential for ensuring that no generated power by wind turbines is lost due to grid disturbances. To deal with these issues simultaneously, this paper presents a comprehensive review of LVRT methods for the most common wind generators; squirrel cage induction generator (SCIG), doubly fed induction generators (DFIG), and permanent magnetic synchronous generator (PMSG). Moreover, the overall view of optimization techniques that are used to enhance LVRT capability for WECSs and the configurations of WECS are investigated. A comprehensive and a useful summary for the recent work in literature regarding LVRT methods for these three wind generators with comparisons and discussion are introduced. To achieve this aim, more than 200 articles are organised and only 135 papers are presented in this review. • Comprehensive review of low voltage ride through methods for the most common wind generators. • Overall view on optimization techniques that are used to enhance LVRT capability. • The configurations of wind energy conversion system are investigated. • Useful summery for the recent work in literature regarding LVRT methods is introduced. [ABSTRACT FROM AUTHOR]

This paper presents a review and analysis of pricing strategies in peer-to-peer (P2P) energy trading to provide new insights into the design of pricing mechanisms and the establishment of sustainable and effective P2P energy markets in distribution networks. P2P energy trading is emerging as an effective management scheme for prosumers with renewable energy sources in distribution networks. Several studies have focused on designing pricing mechanisms for P2P energy trading with a focus on energy pricing but not on network service pricing. To understand the extant pricing mechanisms, 169 papers were systematically reviewed. These papers, published between 2015 and 2022, were retrieved by academic search engines. The review showed that energy pricing can be categorized into synchronous and asynchronous, while network service pricing can be classified into ex-ante and ex-post schemes. Synchronous energy pricing provides economic efficiency. Asynchronous energy pricing offers Pareto optimality and price transparency and accommodates market participant preferences. Market participation can be reduced by conflicts of interest in network service pricing, between system operators and market participants owing to the settlement of network service costs, and among participants due to pricing methods. Energy and network service pricing compatibility between different methodologies relies on market results to distinguish matched counterparties. [Display omitted] • Systematic classification of energy and network service pricing suggested. • Procedure and function of energy-pricing methods clarified. • Potential conflicts of interest in network service pricing discussed. • Compatibility between energy and network service pricing presented. • Key challenges and opportunities for future research identified. [ABSTRACT FROM AUTHOR]

Renewable energies are a key to reducing carbon emissions and enabling access to affordable energy for rural populations in many low- and middle-income countries. For this reason, many governments have started to introduce auctions for off-grid renewable energy. Despite their relevance for clean, accessible energy, the factors for successful or failed off-grid renewable energy tenders have not been broadly studied yet. This paper investigates the success factors for the successful implementation of off-grid energy auctions to enhance rural energy access in low- and middle-income countries. For the scope of this research, the off-grid energy tenders are considered successful if they lead to cost-efficient outcomes, have a high implementation rate and improve the equality of access to energy. Using success measures and success factors from the state of knowledge on energy auctions, three real-world cases from Peru, Uganda and Senegal are analysed and compared. The investigations show that auctioneers should strike a balance between 1) economies of scale and streamlining administrative procedures, 2) allowing adequate product designs for a diverse group of beneficiaries and 3) attracting enough bidders in this relatively young sector. Moreover, this paper confirms that balancing the developers' risks and public risks is essential in designing off-grid energy tenders and that there are several ways to do this. Furthermore, the advantages and limitations of different support payment types are illustrated. Finally, regarding governance, the real-world cases in this research underscore the importance of clarity about responsibilities and procedures, without which significant delays can be incurred. • Off-grid energy auction organizers must balance developers' risks with public risks. • Fixed subsidies provide predictability to policymakers regarding public expenses. • Results-based financing encourages further expansion of projects. • Lack of clarity about responsibilities and procedures can lead to significant delays. [ABSTRACT FROM AUTHOR]

This paper is the editorial for the virtual special issue (VSI) of Renewable and Sustainable Energy Reviews (RSER) dedicated to the 16th Conference on Sustainable Development of Energy, Water and Environment Systems (SDEWES 2021) held from October 10 to 15, 2021 in Dubrovnik, Croatia. The VSI collected both high quality review papers and original research articles presented at the SDEWES Conference in 2021 belonging to the aims and scope of RSER. After a scrutinizing peer review process, 28 articles were accepted and published. These articles deal with techniques and technologies to board on the feasible Renewable and Sustainable Energy Systems. Many of them are multidisciplinary articles addressing almost all the Sustainable Development Goals (SDGs) and providing feasible solutions to the strongly needed decarbonization pathways. • The VSI SDEWES 2021 covers the feasible Renewable and Sustainable Energy Systems. • An overview of the Renewable and Sustainable energy cutting edge techniques. • An overview of the Renewable and Sustainable energy cutting edge technologies. • Feasible solutions to the strongly needed decarbonization pathways. [ABSTRACT FROM AUTHOR]

The growing expansion of distribution systems propelled by high penetration of renewable energy sources, growth of electric vehicles, the integration of energy storage systems, and the implementation of demand-side management strategies have introduced uncertainties related to generation fluctuations, and consumption patterns. These uncertainties are to be modeled precisely and effectively to achieve flawless embedding of the distributed energy resources into the distribution grid. This paper begins by highlighting the growing importance of distributed energy resources in active distribution network planning and then provides a comprehensive overview for methods used in the literature to characterize uncertain parameters, specifically through probability distributions, distributionally robust representations, and robust uncertainty sets. The study principally aims to critically analyze the prevailing techniques for modeling and optimization of active distribution planning problems with high penetration of distributed energy resources under growing uncertainties in physical space, such as intermittency in renewable energy production, demand variation, network topology changes, variability in electric vehicle charging load, and customer attitude towards demand response. Various methodologies, including probabilistic methods, possibilistic methods, stochastic optimization, robust optimization, information gap decision theory, and hybrid approaches, are thoroughly assessed and compared. This comprehensive and comparative assessment aids researchers in selecting the most appropriate uncertainty modeling technique in accordance with the characteristics of uncertain variables and the specific planning problem being addressed. Furthermore this study also examines the implications of cyber space uncertainties in active distribution network planning. [Display omitted] • The conceptual framework and potential areas of analysis in active distribution network planning are presented. • Thorough examination of uncertainty quantification and uncertainty modeling techniques are conducted. • Joint implications of cyber space and physical space uncertainties on active distribution planning problems are explored. [ABSTRACT FROM AUTHOR]

For sustainable industrial growth, it is essential to reduce the energy intensity of production through technological advancements while ensuring cleaner energy sources are available to meet electricity and heat requirements. At the same time, hydrogen holds potential in decarbonizing hard-to-abate industries as a clean fuel. This review aims to develop a comprehensive framework for integrating hydrogen energy to decarbonize industries effectively. It begins with an overview of energy storage technologies, followed by a discussion of hydrogen applications in the industry. A life-cycle assessment of green hydrogen highlights its environmental benefits. The review also provides a systematic analysis of energy system models, leading to the introduction of a framework for hydrogen integration in energy systems. The objective is to demonstrate how hydrogen, supported by renewable energy sources, can serve as a sustainable alternative to fossil fuels, particularly in carbon-intensive sectors. The proposed framework considers four aspects: understanding the current industrial process, evaluating hydrogen's applicability, building a mathematical model to simulate the integrated system, and analyzing the model's findings in terms of energy consumption, environmental impact, and economic feasibility. By following these steps, industries and policymakers can make informed decisions about integrating hydrogen for a more sustainable future, setting a precedent for similar economic sectors. • The development of sustainable energy system models is needed to alleviate pressure on resources and the environment. • Hydrogen has potential as an energy carrier, facilitating more integration of renewable energy. • The paper introduces a framework for hydrogen integration in the industrial energy system. [ABSTRACT FROM AUTHOR]

Under the carbon neutrality goal, the projects to develop zero-carbon microgrids are emerging all over the world. However, the categories, trends, challenges, and future research prospects of the zero-carbon microgrid are still unclear. To deal with this problem, this research first reviews the real-world and simulation cases of zero-carbon microgrids in recent years and classifies them into two categories, i.e., on-grid mode and off-grid mode. Then, three development trends of the zero-carbon microgrid are discussed, including an extremely high ratio of clean energy, large-scale energy storage, and an extremely high ratio of power electronic devices. Next, the challenges in achieving the zero-carbon microgrids in terms of feasibility, flexibility, and stability are discussed in detail. Finally, future research prospects in long-term low-cost energy storage, power/energy balancing, and stability control, are emphasized. [Display omitted] • This paper reviews the trends and challenges to achieve the zero-carbon microgrid. [ABSTRACT FROM AUTHOR]