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To meet fast growing in energy demand, all energy sources have to be exploited. Renewables energies are unlimited and clean but the most problem with them is their intermittent aspect. To overcome this problem a mixture of several energy sources is made to obtain what called hybrid renewable energy system. This paper aims at presenting and analyzing a deep literature review of the recent paper published in hybrid renewable energy field. This review focuses on four essential categories of hybrid renewable energy system which is sizing (using software or using traditional methods), optimization (classical, artificial and hybrid methods), control (centralized, distributed and hybrid control) and energy management (technical objective, economic objective and techno-economic objective). Furthermore, this paper compares between different methods used in each category.

A high proportion of new energy sources are connected to the grid, which not only alleviates the energy shortage, but also brings hidden dangers to the safe and stable operation of the grid. Aiming at the inadequate consideration of uncertainty caused by new energy sources such as wind power being connected to the grid, a method for identifying voltage-dominant cascading fault types is proposed. A voltage-dominant fault analysis model in the sense of probability is established. Based on the fault data, the nonlinear mapping relationship between the initial fault and the fault propagation characteristics is established through the neural network. Finally, the effectiveness of the method proposed in this paper is verified in the IEEE39-bus system, and the simulation results show that the method proposed in this paper can effectively identify the fault types of high-proportion new energy systems.

High step-up, high efficiency, low cost DC/DC converters have operated as an interface to make use of the renewable energy system generated power. In order to obtain desired output voltage, the DC/AC voltage conversion to AC mains voltage is an important consideration mainly achieved through inverters. Taking into acoount the performance of the non-isolated high step-up DC/DC converters for the renewable energy systems, the substantial amount of topologies studied in past years are the non-isolated high step-up DC/DC converters. Based on proposed and generalized configurations, the non-isolated high step-up DC/DC converters are classified into several categories and reviewed in this paper. So, to clarify the distinguishing solutions, the key features; topological variations, merits and demerits of these converters are discussed and compared. This review work aims to give a well-informed and a well-detailed general framework about these converters and facilitates to derive the new well topologies in the future. (C) 2021 THE AUTHORS. Published by Elsevier BV on behalf of Faculty of Engineering, Alexandria University.

A novel optimum arrangement of combinatorial PV/BG/Battery/PSH-based off-grid combinatorial sustainable energy system is suggested in this paper to provide the required energy of a radio transmitter station on the Three Gorges Dam in Hubei, China. The study proposes four decision variables to lessen the overall life-cycle cost under different constraints. To enhance the solution capability, a novel developed version of Student Psychology Based Optimizer (DSPBO) is proposed. The study also works on lessening the levelized energy expense based on the proposed method with a comparison to some various algorithms from the literature. Simulation results showed that in the DSPBO algorithm, OLCC has higher convergence. The optimal design for this algorithm is a OLCC of $ 816,427 and LEOE of $ 0.4913 $/kWh which is the best compared with other analyzed methods. Final simulations show that the presented technique obtains the optimum outcomes with comparison to the others

In order to solve the energy consumption and environmental problems, renewable energy was utilized in many airports. However, due to the periodic and intermittent, a single renewable energy generation is difficult to provide a continuous supply all the time. Hybrid energy system was considered to be the important way to alleviate the intermittent. The study focuses on the optimal design of hybrid renewable energy system planning. A model based on Multi-Criteria Decision Making (MCDM) was constructed. This model could achieve the optimization of scale for renewable energy and energy storage devices in hybrid renewable energy. The model was built in consideration of different power grid operation strategies including “Independence-net operation” and “grid connected operation”. The results showed that the environmental and social benefits could be calculated at the same time, and the optimal renewable energy system scale planning outcome could be obtained.

Dirk Weiss leads technology assessment at First Solar, where he is responsible for finding and incubating new opportunities beyond the company’s cadmium-telluride core technology and assessing current and future competitive landscapes. He studied physics at Freie Universitat Berlin, received a doctorate in materials science from Max Planck Institute for Metals Research in Stuttgart, Germany, and was a postdoctoral fellow at the Massachusetts Institute of Technology. His work experience spans both academia and industry—ranging from a startup to a conglomerate (United Technologies). His technical expertise spans renewable energy systems (photovoltaics, fuel cells, thermoelectric devices), nanotechnology, and material characterization.

Artificial Intelligence (AI) is increasingly playing a significant role in the design and optimization of renewable energy systems. Many AI approaches and technologies are already widely deployed in the energy sector in applications such as generation forecasting, energy efficiency monitoring, energy storage, and overall design of energy systems. This paper provides a review of the applications of key AI techniques on the analysis, design, optimization, control, operation, and maintenance of Solar Tower systems, one of the most important types of Concentrating Solar Thermal (CST) systems. First, key AI techniques are briefly described and relevant examples of their application to CST systems in general are provided. Subsequently, a detailed review of how these AI techniques are being used to advance the state of the art of solar tower systems is presented. The review is structured around the different subsystems of a solar tower system.

18 figures, 8 tables.-- © 2023. This manuscript version is made available under the CC-BY-NC-ND 4.0 license https://creativecommons.org/licenses/by-nc-nd/4.0/, The development of sustainable and renewable energy technologies has received significant attention to realize Net-Zero CO2 equivalent emission goals and meet the growing energy demand. Hydrogen is a promising energy carrier that can facilitate the large-scale deployment of renewable energy sources and assist in the replacement of fossil fuels and to reduce the impact of global warming. The objective of this research is to present an advanced hydrogen-integrated renewable energy system model to meet the energy demand of a distributed community and produce green hydrogen from excess/curtailed renewable energy. The study employs an anion exchange membrane water electrolyzer (AEM) for producing hydrogen. An optimization model of the renewable energy system and a mathematical model of the electrolyzer are developed to achieve this objective. The model uses an energy maximisation approach and optimally combines wind system, biogas plant, and solar PV system to meet the residential and commercial load demands. To increase the system stability, the model is interconnected with the local grid station for energy exchange. Moreover, an uncertainty analysis is also performed to analyse the system response under random variation in load demand. The study results show that a significant amount of clean energy (15,025 MWh/year) is produced by the system at the lowest levelized cost of 0.084 €/kWh and a reduction of 6,078 tons of CO2 emission during the first year of operation is obtained. The electrolyzer produces 63 kg/hr of hydrogen, while the cell performance remains stable at 60 °C and the cell voltage reaches 2.019 V at 2.415 A/cm2 current density., Sincere gratitude and special thanks to the Department of Mechanical Engineering at Northern Illinois University, and the Biomass Research Center, CIRIAF and the University of Perugia for providing the facilities and support to conduct this research work.

The rising of hybrid system controllers, in real-time renewable energy for the optimum energy management system (EMS), required the design of a real-time controller to operate the entire system in real time. The increasing popularity of Renewable Energy (RE) has a control strategy, that determined the overall efficiency of the hybrid system (HS), although the energy management system of these systems is particularly complex to be managed. The paper’s main contribution is to investigate the feasible controller and, later, to present an advanced control strategy for managing and controlling the flow of hybrid renewable energy (HRE) with a diesel generator (DG) and battery (BT) as a backup in rural application of South Africa (SA) . EMS was implemented using a fuzzy logic controller (FLC) in MATLAB/SIMULINK. This study analysed input and output variables for the design of a controller, with a set of rules and a three-dimension (3D) surface. Simulated results are similar studies conducted between previous years and now, however, they differ in their objectives. A Fuzzy Logic Controller (FLC) was considered as the most suitable option to be used to control the entire system and further demonstrated acceptable performance in managing the power flow between the sources under various loads demands, while at the same time storing excess energy in the battery. This study finally answers the question of the feasibility of the controller in real-time applications. However, further investigation is to be conducted, to establish further results in real time, through the programmed FLC for smooth performance in hardware-in-the-Loop (HIL) test equipment.

The necessity of fault detection and notification has been exploited by the growth of renewable energy systems. The application of fault detection and notification is seen as an effective tool to monitor the performance of renewable energy systems. Looking at the importance of fault detection and notification integration into renewable energy systems based on the conducted literature review, this paper presents fault notification mechanism and implementation, which also consist of detection in an IoT-based photovoltaic panel monitoring and analysis system. The implemented fault notification detects the abnormalities of the voltage-current-temperature in the IoT-based photovoltaic panel monitoring and analysis system. The implemented fault notification in the IoT-based photovoltaic panel monitoring and analysis detects and notify any sort of abnormality of the voltage-current-temperature that is recorded at the photovoltaic panel. The implemented fault notification operates based on the threshold values of the voltage-current-temperature that has been programmed in the centralised controller. Hence, when any parameter input is below the preset threshold value, an email notification is sent to the centralised system to notify the maintenance team. Based on the implementation and obtained results, the implemented fault notification in the developed IoT-based photovoltaic panel monitoring and analysis system successfully performed and validated the purpose of the implementation.

Microbial electrosynthesis is increasingly popular, as it couples renewable electricity to microbial metabolism. Currently, electromicrobial production (EMP) to synthesize fuels has yet to surpass laboratory-scale reactions, but continuing improvements in the cost efficiency of these technologies hold promise for their translation to the real world. In this issue of Joule, Barstow and coworkers introduce a computational framework to determine the maximum efficiency of EMP, providing a blueprint for the scaling and broad implementation of these unique, renewable energy systems.

The paper applies the scenario approach to stochastic model predictive control for renewable energy systems. First, the controllable and the (quasi-periodic) uncontrollable parts are decomposed. The latter is modeled by a Box-Jenkins system with appropriately chosen inputs. For the controllable part, a linear state space model is used with an affine state-feedback controller. Several numerical experiments are presented on a public lighting microgrid, e.g., about forecasting the energy balance, the effects of various controller parametrizations, reoptimization frequencies, and discarding unfavorable scenarios. The results indicate that even a low order, time-independent controller with a slow reoptimization frequency can be efficient.

This paper presents the performance study of new Dual Output Quasi Z Trans DC-DC converter. The conventional Z source DC-DC converter is modified in the circuitry to generate dual output voltage which could be fed as input to the cascaded multilevel inverters feeding the renewable energy systems. This reduces source count requirement of the cascaded multilevel inverters and efficient operation is obtained by controlling the duty ratio of the converter. The proposed converter is studied for different switching frequencies and duty ratios to identify the optimum value. The circuit model of the proposed DC-DC converter is built in MATLAB /Simulink to analyze the performance and the prototype hardware is developed to validate the findings. The results are discussed and is compared with the literature findings.

In this paper a supervisory strategy for load/frequency control problems in networked multi-area electrical micro-grids in the presence of Renewable Energy Systems (RES) is presented. The proposed strategy exploits a recently developed constrained supervision methodology known in the literature as the Reference-Offset Governor (ROG) approach. Here, the ROG approach is extended to operate in the presence of rate-bounded disturbances acting as non-manipulable inputs on the plant. The main aim is at adequately orchestrating, during the on-line operations, the switching among different ROG configurations, suitably calibrated on the intensity of the disturbances, to efficiently satisfy the prescribed constraints. It is shown that the use of a bank of ROGs, instead of a single one, can remarkably reduce the conservativeness of the solution and improve the overall performance if the disturbance intensity changes. The effectiveness of the proposed approach is demonstrated on a two-area power system subject to coordination constraints on maximum frequency deviations, exchanged and generated powers and injected power from local RESs.

With the rapid surge of renewable energy integrations into the electrical grid, the main questions remain; how do we manage and operate optimally these surges of fluctuating resources? However, vast optimization approaches in renewable energy applications have been widely used hitherto to aid decision-makings in mitigating the limitations of computations. This paper comprehensively reviews the generic steps of stochastic optimizations in renewable energy applications, from the modelling of the uncertainties and sampling of relevant information, respectively. Furthermore, the benefits and drawbacks of the stochastic optimization methods are highlighted. Moreover, notable optimization methods pertaining to the steps of stochastic optimizations are highlighted. The aim of the paper is to introduce the recent advancements and notable stochastic methods and trending of the methods going into the future of renewable energy applications. Relevant future research areas are identified to support the transition of stochastic optimizations from the traditional deterministic approaches. We concluded based on the surveyed literatures that the stochastic optimization methods almost always outperform the deterministic optimization methods in terms of social, technical, and economic aspects of renewable energy systems. Thus, this review will catalyse the effort in advancing the research of stochastic optimization methods within the scopes of renewable energy applications.

Renewable energy systems have become an integral part of the energy grid, necessitating the self-cleaning shields and green energy management strategies. The critical issues related to compatibility and service-life of energy devices have been lingering on since the birth till date. And because of the less-immune surfaces of energy devices against environmental dust, dirt, water, fog, ice, bio-organisms and salts, etc., the power and longevity losses are comparatively foreseeable even in the years to come. This review has twofold objectives: promoting the concept of bioinspired slippery technology to protect and improve the power generation of energy devices, and unveiling the development and design rationale of bioinspired slippery surfaces fabricated by phase change materials. Meanwhile, the pros and cons of these slippery surfaces have been emphasized along with a critical appraisal, serving to identify the advanced features of phase change materials versus phase invariant materials.

Residential consumers in the U.S. have demonstrated a growing interest in rooftop photovoltaic (PV) systems, resulting in increased adoption over the last decade. However, this has diminished utility revenues, and policymakers have expressed concerns about inequitable consumer access to publicly-funded rooftop PV adoption incentives. In response to these concerns, policymakers and utility companies are changing their policies to discourage rooftop PV adoption. Alternative renewable energy models, such as utility-provided community solar programs, offer a potential solution. However, when designing such programs, it is important to consider the potential impacts on different system stakeholders, including utilities, policymakers, and solar installers. This paper describes an agent-based model that predicts the performance of different residential distributed solar models with respect to these stakeholders' objectives. In this model, consumer agents residing in an urban utility territory decide in each time-step whether they will adopt a particular renewable energy model, and the impacts of their adoption decisions on stakeholder performance metrics are captured over time. Simulation results suggest that if community solar program premium prices are set appropriately, all stakeholders can benefit: the utility can recover part of its revenue losses even as rooftop PV adoption increases, solar installers’ businesses can thrive, and increased renewable energy adoption can be achieved equitably. The proposed modeling methodology can help to inform design decisions of distributed solar energy models that avoid benefiting some stakeholders at the unnecessary expense of others.

This article review system optimization and energy management strategies (EMS) for a standalone photovoltaic and wind energy system integrated with fuel cell. The goal of optimization is to determine the combination of the system components in order to compose a cost-effective system. The EMS is aimed to coordinate the power flow of the system components while satisfying load demand and other constraints. System optimization and EMS are combined such that it is unusual to discuss them individually from a system-level design perspective. Therefore, in this paper, the general optimization formulation framework, the classification and the review of various types of optimization methods are elaborated. Furthermore, the literature on EMS application and research is reviewed. As the core of this review, all system optimization methods and EMS are analyzed and compared by reviewing several cases from the literature. In addition, recommendation for future research as well as the associated challenges are highlighted. It is hoped that this review will serve as a fundamental platform for researchers intending to explore renewable energy system integrated with fuel cell for further improvement.

Using data from the German Socio-Economic Panel, we undertake a simultaneous assessment of the importance of factors that are individually found to be significant for the adoption of renewable energy systems by households but are not yet tested jointly. These are sociodemographic and housing characteristics, environmental concern, personality traits, and economic factors; i.e. the expected costs of and revenues from the investment. Our results suggest that household decisions to invest in photovoltaic systems and solar thermal facilities are mainly driven by economic factors. Taking account of sociodemographic and housing characteristics, environmental concern, or personality traits has comparatively little relevance, while the quantitative nexus between the decision to invest and returns on the investment is robust to their inclusion.

In its 2016 Heating and Cooling Strategy, the European Commission (EC) highlighted the strategic importance of heating demand for the energy demand reduction, and further noted that District Heat Networks (DHN) can play an important role in decarbonising this sector. This study applied a thermal atlas approach to map the potential for district heat networks in Switzerland. It extended existing methods with a novel approach to estimating linear thermal demand density in DHN at a national scale. DHN potential for current-generation high temperature networks as well as cutting-edge low temperature networks were compared for current building space heating and hot water demand as well as for two demand reduction scenarios. The method was tested by comparing its results to those of a local engineering study conducted for a Swiss municipality (Brig-Glis). The potential percentage of demand supplied by high temperature DHN was shown to decrease from 66% to 41% with energy saving while the potential for low temperature systems increased significantly from 2.1% to 42%. The percentage of heat demand covered by heat networks decreases less than the percentage of buildings covered, reflecting the strength of heat networks for supplying large fractions of thermal demand in geographically confined areas.

This paper investigates the interplay between the German incentive regulation and renewable capacity integration. A comprehensive review of the current incentive regulation scheme and its 2016 amendment is first presented. Then, results of ten representative interviews with large-scale distribution system operators are analyzed. Firstly, all necessary grid integration measures could so far be implemented. Secondly, creating proper incentives for intelligent operating equipment to partly substitute conventional grid expansion remains a challenge. Thirdly, the new curtailment regulation of 2016 is welcome, but will not become a substitute for grid expansion as long as renewable integration rates are high. Moreover, the discussions on further improvements to the incentive regulation scheme reveal a distribution conflict between grid operators and grid users.

Seawater air conditioning systems use cold water from the deep ocean to provide cooling utilities to buildings. Their design, as with other renewable energy systems, involves the participation of multiple stakeholders with different preferences and objectives. A multi-objective strategy based on compromise solutions for reducing the dissatisfaction between multiple participants is presented. The dominant stakeholder is considered to have predominant participation, opinion, and weight in the final decision of the project. The presented decision-making framework allows for the resolution of conflicts and shows the effects of different criteria on the final configuration of the system. This work presents an optimal design model considering, as a case study, a touristic zone in Mexico. The results show significant differences between scenarios where all the stakeholders are considered under a condition of equality and one in which only the dominant stakeholder is considered. This decision-making approach shows flexibility and provides tolerance limits for compromise solutions that still consider the influence of the dominant stakeholder.

This work evaluates potentials of photovoltaic and battery systems with additional micro-generation wind turbines (10.5 kW) to cover electricity demand of residential users in two countries in Central Europe. It relies on high-resolution regional reanalysis data and a techno-economical optimization model. Maps showing the number of wind turbines, photovoltaic and battery systems sizes necessary to supply electricity for clusters of electricity self-sufficient single-family houses across Germany and the Czech Republic are generated. No general trends that apply for the two countries concerning the relation between the sizes of the different technologies were identified. However, it was possible to determine several large areas where the inclusion of small wind turbines decreases the total system costs and considerably reduces the required storage capacities. Results are discussed and compared to previous work on self-sufficient single-family houses.

In comparison with current financing mechanisms for renewable energy systems, crowd-funding financing mechanism offers a new potential source of financing with recent use of social media. Crowd-fun ...

Due to the privileged location of Ecuador in terms of solar radiation, the analysis and use of renewable energy system (RES) using solar energy has been of great interest during the last years. At the same time, the supply support of RES in terms of direct current (DC) can be faced by using fuel cell (FC) systems which can give to the systems fully autonomy from fossil fuels. The aim of this paper is to propose the design of a hybrid photovoltaic-fuel cell-battery (PV-FC-B) system to supply the required electrical energy for residential use in the city of Guayaquil. The feasibility analysis, constitutive elements of the system, and adjusted variables are computed and presented using a computational tool. The results evidence that this system is not economically viable since the cost of energy (COE) in Ecuador is low compared to the COE of the proposed system. However, a more detailed analysis considering the inherent benefits of no emission of pollutant gases is required to have a complete outlook.

As one of the largest energy consumers and greenhouse gas (GHG) emitters, the mining industry is switching to renewable energy to help reduce its energy and environmental impacts. There are already renewable energy systems (RES) in operation at large-scale mines. However, for off-grid small-scale mining operations, conventional diesel generators are still preferred given their mobility and modularity. The aim of this paper is to assess the techno-economic feasibility of RES for switch-on, switch-off mining, an emerging concept for mobile small-scale mining, in Europe. Simulations were performed using the HOMER Pro software to evaluate whether mobile and modular containerised RES available on the market are economically viable compared with diesel generators for potential mine sites across Europe. The results suggests that mobile and modular containerised RES are technically and financially feasible for powering switch-on, switch-off mining at different geographical locations in Europe, with varying system designs depending on the renewable resources available and providing significant reductions in GHG and air pollutant emissions. However, the use of RES in SSM could potentially have both positive and negative environmental and social impacts from a life cycle perspective, which extend beyond the mine site due to a diverse supply chain and deserve further research.

This paper proposes an alternate soft switching scheme for a dc-dc boost converter applicable to renewable energy systems. An auxillary circuit is value added along with the boost circuit to provide soft switching features like zero voltage switching (ZVS) for main switch turn ON and zero current switching (ZCS) for main switch turn OFF. Active snubber circuit uses a single switch and some passive components. The converter circuit as a whole uses fewer components with smaller size and simple controls. The proposed converter is analyzed mode wise and therefore the simulations are meted out in PSIM beneath big selection of loading conditions. The circuit attains sensible potency and low element stresses.

Thermal energy storage (TES) is a key technology to reach a real renewable sources integration in the energy system, helping in the energy transition that the world is facing nowadays. Advances in TES in all areas related to renewable energies are shown in this special issue, with the aim of providing answers to scientists and practitioners who may need such knowledge. This special issue only includes invited papers from a total of 104 papers presented at the Eurotherm Seminar #112 conference that took place between May 15-17, 2019 at the University of Lleida, Spain. The Seminar brought together researchers and practitioners from academia and industry working on topics related to TES. Recent trends in TES for renewable energy systems, as well as novel storage materials and advanced storage concepts and configurations communicated during the conference, are featured in the papers selected for this special issue.

This study was conducted to ascertain how the use of recycled materials instead of virgin materials affect the installation of renewable energy systems for the energy transition of buildings. LCA was used to estimate the life cycle energy use and GHG emissions of building and renewable energy systems with and without using recycled materials. For the case study, a public building and four representative photovoltaic (PV) systems were selected. National recycling standards and processes were considered for suggested recycled materials. In general, replacing virgin material with recycled counterpart reduced embodied GHG emissions more than embodied energy. However, due to high carbon intensity of operation energy and building materials without available counterparts, using recycled materials reduced the life cycle energy use and GHG emissions of the case building by 4.9% and 3.3%. Among four PV systems, using recycled materials was most significant in the single crystalline-silicon (sC-Si) PV system, 44.5% reduction of energy use and 41.3% reduction of GHG emissions. Therefore, when recycled materials are used for achieving the energy transition of the case building with the sC-Si PV system, the PV system requirements could be reduced by a maximum of 9.6% for energy payback and 4.9% for GHG payback. This study demonstrated that the use of recycled materials is effective at reducing the embodied energy and GHG emissions of PV systems as well as buildings. To achieve carbon-neutral buildings, particularly, the use of recycled materials based on a thorough LCA should be considered in addition to renewable energy system.

The adoption of decentralized renewable energy technologies (RTech) is a challenge in rural sub-Saharan Africa (SSA) despite their potential to increase the living standards of people in these areas. RTech such as solar photovoltaics, biogas digesters and improved cook stoves are disseminated in SSA to supply affordable energy, reduce indoor air pollution, combat deforestation and climate change. Despite extensive research and development in facilitating dissemination over the past five decades, significant challenges still hamper the adoption and sustainability of RTech. This paper reviews current literature on RTech adoption in SSA from a socio-technical perspective to examine the relationship between RTech and users. Three attributes of innovation (i.e., relative advantage, compatibility and complexity) are used to examine user behavior during RTech adoption. In this study, we examine whether and how the attributes of innovation generate disruptions in adopters’ daily lives and how these changes influence the adoption decision process. This is particularly important in rural SSA because it reveals the appropriateness of RTech from different and sometimes interrelated perspectives. The study found that RTech adoption is likely to be high when benefits (i.e., lighting, short cooking times and income savings) are immediate and easily understood. However, RTech compatibility changes with adopter socio-economic status, especially when benefits such as lighting are highly valued. With more than half of the studies reviewed investigating only one innovation attribute, this paper makes a significant contribution to the literature by adopting a multi-dimensional analytical approach.

This paper proposes a methodology that is based on mixed-integer linear programming (MILP) to calculate the optimal sizing of a hybrid wind-photovoltaic power plant in an industrial area. The proposed methodology considers the: i) load requirements; ii) physical and geometric constraints for the renewable plants installation; iii) operating and maintenance costs of both wind and PV power plants; and the iv) electric energy absorbed by the public network. The power demand variation associated with the production cycles is considered by using a stochastic simulation tool. To consider both the load and seasonality variability, and to adapt the methodology to the actual operational use of the power plant, the optimization is performed separately for each month of the year. Then, an integrated economic analysis is discussed. The methodology is adopted to analyze an industrial plant in the Rome area used as a train depot and for maintenance purposes. The results, which combine the needs of the plant activity with the availability of renewable energy, enabled the determination of optimal solutions and the relevant savings achievable.

Renewable energy systems can be used to improve the buildings thermal performance and to design sustainable buildings. To achieve maximum thermal comfort inside the housing test modules for all weather conditions without using any form of energy from fossil fuels which could be obtained from renewable energy systems. Different modules type (Cavity Brick (CB), Insulated Cavity Brick (InsCB), Insulated Brick Veneer (InsBV) and Insulated Reverse Brick Veneer (InsRBV)) with the type of renewable energy systems is performed to determine which type could provide the greatest energy savings with the least cost. InsCB the best performing module but it cost more to build while InsBV module cost less but with lower thermal performance which can be compensated by using Photovoltaic systems (PV) to enhance the thermal performance with the least cost.

As one of the renewable energy systems, the enhanced geothermal system (EGS) played an important role in relieving energy crisis as a supplement for the existing energy systems. The costs were a key factor restricting the practical application of an EGS project. Therefore, an economic analysis before the establishment of EGS is particularly important to conduct. The aim of this research is to discuss the influences of stratigraphic and operating parameters on the total net costs of geothermal system. In this article, a thermal transfer and economic analysis model was established and the operation of EGS in ten years was simulated. The effects of the parameters including well spacing, injection flow rate, geothermal gradient and drilling costs on total net costs were analyzed. Results showed that the well spacing was one of the most important factors affecting the total net costs. And the total net costs were the lowest in the well spacing around 200 m. During the system operation, there was an optimum injection flow rate which made total net system costs the lowest. The optimum injection flow rate was significantly affected by the well spacing. A higher geothermal gradient could also reduce the total net costs.

Hybrid renewable energy system (HRES) has been widely utilized on national, regional or building levels, as its ability of reducing carbon emissions and easing energy consumption intensity. Techno-economic analysis of HRES is essential to embody its superiority and identify what kind of system and corresponding considerations are needed for a certain situation. This paper presents a comprehensive review of techno-economic analysis methods for the systems at national, regional and building scales. All methods are discussed in a comparative way including 31 computer tools and 20 arithmetical models. Main features, applications and merits of these methods are introduced and compared in detail regarding the analyzed space. Problems such as improper use of analysis methods or ignoring specific considerations may occur in the process of HRES designing and evaluating. As a result, a framework is proposed for techno-economic analysis of HRES at different spatial scales, including promising analysis process, research constraints and recommended tools for fulfilling different objectives. This framework provides critical references for researchers, decision makers and system designers, further supporting the application of future HRES.

The concept of urban CO2 networks has been developed to deploy heat pump based district heating and cooling systems in dense urban areas. The use of the CO2 phase change reduces the cost of the heat distribution while allowing to recover waste heat that is typically rejected to the environment. The use of heat pumps to harvest heat from the environment and to supply heat to buildings allows one to propose district systems with COP as high as 6. Heat pumps can use the electricity produced by photovoltaics already providing up to 60% of the total consumption. This paper studies the integration of fuel cell based power to gas for the seasonal storage of the excess electricity produced in the summer by PV panels. The methane stored in liquid form is used in the winter to balance the electrical needs by fuel cell based co-generation, making therefore the city 100% supplied by renewable energy. The present work evaluates the integration of CO2 district energy network including power to gas systems on a compact urban block considering heating, cooling, electricity, e-mobility and waste management for different European climatic zones. In order to reach fully autonomous blocks using solar PV and municipal and industrial waste heat, a PV area of 10–35 m2/cap would be needed. The rooftop area available appears to be sufficient in areas like Southern Europe, while more area or alternative renewable sources such as wind or hydro are needed for other climatic zones. Regarding the economic feasibility of the system, the results show that an investment of 900–1300 €/cap would be needed, with a payback time between 11 and 14 years, depending on the different climate zones in Europe.

It is well known that the cost of installing renewable energy system (RES) in building for achieving net zero energy building (NZEB) is much higher than the building without or with a smaller size of RES, this is definitely a barrier for promoting NZEB application. This study is therefore conducted to investigate the design optimization of RES by introducing penalty cost. Considering the penalty cost, building owners will be given bonus according to electricity supply and building energy demand, i.e. safety factor. The results show that the total cost (IOPC) of the building under safety factor of 0.0 (no RES) is about three times than that of the building under safety factor of 1.0 (i.e. NZEB). And the owner of NZEB will only be required to pay half of the original cost due to the introduction of penalty cost. It is believed that the results of this study can provide a progressive perspective in terms of both government as well as building designers/owners for its significant profit. More types of penalty cost mechanism will be investigated in our future work.

Renewable energy is increasingly used in the building nowadays, how to scientifically evaluate the renewable energy utilization efficiency is a problem worthy of study. Considering extra conventional energy consumption, based on exergy analysis method, a general formula is proposed to evaluate the utilization efficiency of the building renewable energy. The evaluation indexes of substitution rate are deduced, which is divided into two categories. One is for single kind of renewable energy output, another is for multi-output, which can get two or more cooling, heating or domestic hot water by the same renewable energy system. The building common renewable energy system ground source heat pump (GSHP) for heating and cooling, and solar thermal system for heating are analyzed in this paper with the method. The results show that for single kind of renewable energy output, if the exergy efficiency of conventional energy system is greater than the renewable energy system, the renewable energy substitution rate must be less than zero, which means the renewable energy utilization shouldn’t be encouraged. For renewable energy multi-output, if the substitution rate for one kind of output is minus, another kind of output is greater than zero, the total substitution rate may be more than or less than zero, which should be calculated to estimate the renewable energy utilization is reasonable or not. For ground source heat pump(GSHP) system, the higher the efficiency of the conventional energy system, the less obvious the substitution of renewable energy is. For solar thermal system, the main factor affecting substitution rate is solar fraction ratio.

To better facilitate renewable energy systems, the district heating sector is currently changing towards lower temperatures and increased cross-sectoral integration. Seasonal thermal energy storage systems alongside heat pumps have received an increasing attention. However, the operation of a seasonal thermal energy storage system alongside a heat pump is more complex than a short-term thermal energy storage system, and as such, several complex simulation models have been developed. These models have shown to be usable for simulating the operation, but due to their complexity are difficult to implement in simulation models that focus on overall energy system analyses. Based on the operation of an existing seasonal thermal energy storage system, this paper provides a simulation method for a seasonal thermal energy storage system with a heat pump that can be utilized in overall energy system simulation models. The simulation method is based on the proven different operational situations of the seasonal thermal energy storage system. The method is shown to be able to approximate the actual operation on an hourly basis and the yearly thermal losses.

Renewable Energy and Sustainable Supply Chain Management have been extensively studied over the last decade. However, techniques based on the modelling and simulations have not been applied extensively in the supply chain of renewable energy. The main purpose of this study is to identify the latest System Dynamics contributions and trends related to the supply chain of renewable energy. An overview of works published in several journals and related to the application of the System Dynamics approach in Renewable Energy Supply Chain (RESC) is provided. Only 10 papers focusing on the application of system dynamics in RESC were found and these were classified into three groups of analysis. Although the literature is scarce, this work shows the importance of system modelling considering: (i) improving the understanding of supply chain in renewable energy and (ii) developing modelling and simulation approaches in renewable energy systems. This paper represents a source for elaborating a System Dynamics framework applied on RESC and provides a comprehensive bibliography of papers published in the last decade.

In recent years, to fast and accurately extract the grid voltage information, using cascaded delayed signal cancellation (CDSC) operators in the prefiltering stage of phase locked loops (PLLs) has become highly popular. Non-adaptive CDSC (NCDSC) operators do not cause the stability problems unlike adaptive CDSC operators. So, researchers use the NCDSC operators intensely. Nonetheless, the NCDSC operators have two main drawbacks: (1) the dynamic responses of NCDSC-PLLs are not fast enough, similar to adaptive CDSC operators-based PLLs; and (2) the imbalance rejection capability of the NCDSC-PLLs dramatically deteriorates in case of large frequency variations. In this paper, to overcome these problems, two enhanced NCDSC-PLLs, which are called the ENCDSC-PLL1, and ENCDSC-PLL2, are suggested. The parameter design procedures of suggested PLLs are given by means of their small- signal models. Since the proposed ENCDSC-PLLs are the nonminimum-phase systems, their stability analyses are evaluated by Nyquist diagram. The feasibility and effectiveness of the proposed ENCDSC-PLLs are validated by experimental results.

Since the main part of a stand-alone Renewable Energy System (RES) is related to the battery, effective means of reducing the energy ‎mismatch between generation and demand could be obtained using such devices. But with the advent of new types of batteries with unique capabilities, choosing the right type of battery used in stand-alone RESs, in terms of technical and economic components including battery life costs, operation costs, and repair and maintenance costs, has become a very important issue. This research tries a significant step forward since previous conducted researches on ‎storage systems are based on oversimplified economic battery models, considering the impact of power generation and consumption, as well as the impact of battery lifetime on battery lifetime-related costs. Considering the battery lifetime feature, multi-objective optimization has been provided to minimize the costs and maximize the useful lifetime of the system through the Teaching-learning-based optimization (TLBO) algorithm. Technical and economic analysis shows that the generation cost of each scattered product varies according to the type of battery optimization and with increasing system useful life, the TCPDBES index system increases. The results illustrate that the battery type selection varies according to the grid-independent lifetime and the ‎use of Lithium-ion battery, Gel Lead Acid battery, and AGM (Absorbent Glass Mat) Lead Acid types has the minimum energy storage cost for 15, 10, and 5 year lifetimes, respectively.‎‎

This paper presents an extensive study of a new metaheuristics algorithm called Smell Agent Optimization (SAO) on some CEC numerical optimization benchmark functions and Hybrid Renewable Energy System (HRES) engineering problems. The SAO implements the relationships between a smell agent and an object evaporating a smell molecule. These relationships are modelled into three separate modes called the sniffing, trailing and random modes. The sniffing mode simulates the smell perception capability of the agent as the smell molecules diffuse from a smell source towards the agent. The trailing mode simulates the capability of the agent to track the part of the smell molecules until its source is identified. Whereas, the random mode is a strategy employed by the agent to avoid getting stuck in local minima. Thirty-seven commonly used CEC benchmark functions, and HRES engineering problem are tested, and results are compared with six other metaheuristics methods. Experimental results revealed that the SAO can find the global optimum in 76% of the benchmark functions. Similarly, statistical results showed that the SAO also obtained the most cost effective HRES design compared to the benchmarked algorithms.

Hydropower plays an important role in the safe, stable and efficient operation of power systems, especially with current trends toward renewable energy systems. The total global potential of gross, technical, economic, and exploitable hydropower are still enormous in the future, and the developments of new hydropower stations (HPSs) are of great importance. For constructions of new HPSs, the condition of setting surge tanks (CSST) is crucial for various perspectives, e.g. safety, stability and economy of HPSs. In this review, the CSST are summarized and analyzed from the three aspects: regulation assurance, operation stability, and the regulation quality, with an aim of providing a reference and guidance for research and engineering applications regarding surge tanks. Upstream and downstream surge tanks in conventional HPSs and pumped storage power stations are all included. Moreover, a comprehensive comparison of CSST under different conditions is conducted. One of the main focuses of this review is on Chinese studies, for introducing many meaningful results written in Chinese to more readers all over the world.

High-tech products as well as renewable energy systems require ever-increasing quantities and more different metals. The extraction of metals and industrial minerals for the production of consumer goods and machines take place almost exclusively on land now. However, the interest in marine mineral resources has been re-inflamed due to the problem of geopolitical availability, such as fragile or failed raw material states and oligopolistic structures among the producers. This article gives a brief outline of the political, social and economic context of this change in interest in marine mineral raw materials extraction.

Supercapacitors (SCs) have high power density and exceptional durability. Progress has been made in their materials and chemistries, while extensive research has been carried out to address challenges of SC management. The potential engineering applications of SCs are being continually explored. This paper presents a review of SC modeling, state estimation, and industrial applications reported in the literature, with the overarching goal to summarize recent research progress and stimulate innovative thoughts for SC control/management. For SC modeling, the state-of-the-art models for electrical, self-discharge, and thermal behaviors are systematically reviewed, where electrochemical, equivalent circuit, intelligent, and fractional-order models for electrical behavior simulation are highlighted. For SC state estimation, methods for State-of-Charge (SOC) estimation and State-of-Health (SOH) monitoring are covered, together with an underlying analysis of aging mechanism and its influencing factors. Finally, a wide range of potential SC applications is summarized. Particularly, co-working with high energy-density devices constitutes hybrid energy storage for renewable energy systems and electric vehicles (EVs), sufficiently reaping synergistic benefits of multiple energy-storage units.

This article reports on an in-depth multiple case study into the adoption of green modular innovations in the housebuilding sector. This adoption of green modular innovations is important because it enables a substantial improvement in terms of sustainable building. For this study, three modular innovations were selected – a modular renewable energy system, a modular bathroom pod and a modular photovoltaic roof. The multiple case study helped to identify ten variables that influence the adoption of these modular innovations. A closer analysis also revealed interrelations between several of the identified variables. Based on this analysis, four paths leading to the potential adoption of green modular innovations were identified. For each path, propositions were developed. These paths enable one to explain how and why green modular housing innovations are adopted. From these findings we derived clear managerial and policy implications while future research directions are also addressed.

Decentralized energy systems have numerous advantages over mega energy projects, including environmental friendliness, lower upfront costs, greater affordability and reliability, lower risks, an easier ability to cope with system failures, and community empowerment. Despite these advantages, the type of governance used when constructing these systems can play an important role in yielding these positive impacts to local communities. This study investigates how renewable energy projects can fail under certain types of governance. We use case studies in Indonesia and Nepal to demonstrate the problems and factors in terms of the governance structures that have diminished the performance of decentralized small-scale renewable energy projects. The Indonesian case study focuses on the top-down governance of a renewable energy project. The project’s promotion under a conventional central government-led framework resulted in a process of granting renewable energy plants to local governments without considering stakeholders. In the Nepalese case, a renewable energy project was designed using a polycentric approach to governance. However, the donor (the European Commission) remotely controlled the project process, thereby hampering the intended polycentric governance strategy, which was originally conceived to include multi-level stakeholders. By focusing on real cases throughout a project’s progress, this study illustrates how monopolized power excludes the interests and commitments of multi-stakeholder interests and commitments to a project, which impinges on the final result.

Hydrogen storage systems (HSSs), are the backbone of feasible hydrogen economy. To provide a reliable renewable energy system, safe, cost effective and compact HSS is due. Physical storage systems involve the compressed gas, liquid and cryo-compressed techniques while material based one involves adsorptive materials, metal hydrides and chemical storage materials. In this paper, the features of a variety of HSSs are impartially discussed. The technical comparative analysis of the different physical and material based types of HSSs illustrates the paradoxical inherent features, including gravimetric and volumetric storage densities and parameters associated with storage and release processes, among these systems. Accordingly, no ideal hydrogen storage technique can be considered the best-fit for all stationary and automotive applications. Therefore, not only a unique HSS solution can properly provide the needs, but a set of complementary HSS solutions which may offer the system designer several options. This set of options can be hardly interpretable in case of the unclear definition of the application needs which may be time variant. Inside this review, the critical insights and recommendations about suitable applications for storage systems are provided. Different standards and codes alongside the corresponding tests are demonstrated for the different storage technologies. Moreover, storage vessels research work is overviewed for the different hydrogen storage technologies. In addition, the failure behaviour, criteria and prediction models are investigated for composite vessels subjected to high pressures and extreme temperatures degrading their mechanical behaviour and failure resistance.