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This paper proposes a multi-electrolyzer switching scheduling strategy based on the Pelican Optimization Algorithm (POA) to enhance the efficiency of large-scale wind power hydrogen production systems. To validate the effectiveness of the proposed strategy, we analyzed wind power data from three typical days in northern Hebei, China, with a 2.5 MW wind turbine output. We designed three strategies for comparative analysis: a simple start-stop strategy, a rule-based multi-electrolyzer switching strategy, and a POA-based multi-electrolyzer switching strategy. The study results demonstrate that the POA-based strategy exhibits higher hydrogen production efficiency and system stability under various wind conditions. Particularly, in extreme wind scenarios, this strategy significantly reduces the start-stop cycles of electrolyzers, thereby lowering operational costs and improving overall system performance. The main contribution of this study lies in the novel optimization algorithm and its validation through real-world data, demonstrating its effectiveness in large-scale wind power hydrogen production systems. Our findings provide new insights for enhancing the utilization of renewable energy and the economics of hydrogen production systems. [ABSTRACT FROM AUTHOR]

Abstract In this paper, a new version of shuffle frog leaping algorithm (SFLA) which called modified SFLA (MSFLA) is proposed. To drive the proposed method both local and global search mechanisms in the original SFLA are modified. The local search mechanism is modified by introducing the movement inertia equation of particle swarm optimization (PSO). Furthermore, the global search mechanism is modified using the crossover and mutation operators of genetic algorithm (GA). Also, the formulation of the combined heat, emission and economic dispatch (CHEED) problem considering the availability of wind and solar power is presented where the objective functions of the CHEED problem are converted into a single objective function using price penalty function. Then, the proposed MSFLA is employed to solve the problem of CHEED with wind and solar power. To show the effectiveness of the proposed MSFLA, different test systems with different scenarios are used. In addition, the scalability of the proposed MSFLA is tested using large-scale test systems. The results of the proposed MSFLA are compared with those obtained by other heuristic and non-heuristic published methods. The comparison with other methods proves the efficiency and the superiority of the proposed MSFLA over other methods in all scenarios. Highlights • A new version of SFLA is proposed in this paper. • This version is derived by modifying local and global search mechanisms in SFLA. • The proposed method is used to solve the CHEED problem with renewable sources. • The proposed method has been evaluated using different test systems and cases. • Results of all cases show the superiority of the proposed method over other methods. [ABSTRACT FROM AUTHOR]

Highlights • Variable renewable energy integration diminishes synchronous inertia of power systems, resulting in vulnerable frequency instability. • Alternative options of fast frequency resources are required for secure and stable grid operation under high penetration of renewables. • This paper provides a critical review of potential sources of fast frequency reserves, and way forward to maintain secure and stable grid operation. Abstract The last few decades have seen renewable energy source (RES) integration growing at a rapid pace and this trend is likely to continue. The displacement of conventional synchronous plant, particularly at higher RES shares, is resulting in a 'lighter' system with low system inertia and reduced governor droop stiffness, leading to increased vulnerability to fast frequency stability. This paper presents a review of literature from the research and industry communities on possible sources of non-synchronous fast frequency reserve, considered as a potential solution to address diminishing synchronous reserve in RES integrated systems. The wide range of potential sources includes wind turbines, solar photovoltaic plant, energy storage, high voltage direct current (HVDC) systems, and demand response. The challenges and limitations associated with each approach are highlighted, and alternative strategies to maintain a minimum volume of security constrained fast frequency reserve are discussed based on the recent industry trends. [ABSTRACT FROM AUTHOR]

Abstract The present paper presents the methodology and development of a planning tool for the installation of marine renewable energy systems, which enables the identification of suitable areas for this purpose. The marine spatial planning is one of the challenges of the offshore renewable energies. This is one of the reasons to write this paper, because there are areas where the energy potential is great but with real limitations for installing an offshore renewable energy farm. This methodology is based on the development of automated and interactive GIS tools in order to enable the user to change inputs according to his research objectives. The developed tools are applied to a case study referring to the Portuguese coast and the obtained results enable the identification of several areas, suitable for the development of marine renewable energies projects. The methodology and the developed tools intend to be a contribution for the Maritime Spatial Planning of the Portuguese coast and can be applied to other countries as well whenever the necessary information is available. Highlights • Methodology and development of a planning tool for marine renewable energy. • Identification of suitable areas of installing. • GIS tools to change inputs according to his objectives. • Maritime Spatial Planning of the Portuguese coast. • Results identify suitable areas for marine renewable energies. [ABSTRACT FROM AUTHOR]

Abstract Wind turbines are emerging as one of the most promising and cost-effective renewable energy sources, due to their economical merits and technical maturity. It is important to accurately predict the aerodynamic performance of rotor blades for efficient design of wind turbine. Among the various numerical approaches, the vortex lattice method (VLM) is one of the most suitable models for wind turbine aerodynamics because the wind turbine mostly operates in the subsonic flow. However, it inherently cannot predict the nonlinear aerodynamic characteristics at a high angle of attack. In the current paper, a nonlinear vortex lattice method (NVLM) has been suggested to extend the existing VLM for handling the nonlinear stall and post-stall behaviors. This can be possible by finding a control point in the airfoil where the effective angle of attack is applied. This paper mainly discusses the development and validation of the NVLM for predicting the aerodynamic performances and the wake geometry against the measurements on the MEXICO rotor model. The comparison results show that the aerodynamic loads and tip vortex trajectories computed by NVLM are in significantly good agreement with the measured data. In addition, the complicated and unsteady wake structures are also analyzed using vortex particle method. Highlights • The nonlinear vortex lattice method can consider the post-stall behaviors. • The most suitable location of control point is half chord for vortex lattice method. • The strong wake interaction and tip vortex breakdown occur at low wind speed. • The wake structure becomes stable and expansion angle reduces at high wind speed. [ABSTRACT FROM AUTHOR]

Abstract Addressing environmental concerns alongside economic development and energy transitions is a challenge for all countries and effective policy making requires approaches that can balance all these concerns. In this paper, combining a range of modeling methodologies is proposed as a way of addressing these questions in an integrated manner. The choice of models to be used would depend on the specific characteristics of the system and region being studied. One possible combination of models is discusses in this paper for the specific case of India. The Integrated Modeling Framework (IMF) proposed combines three modeling approaches – i) index decomposition to estimate impacts of structural changes in the economy, ii) constrained optimization to estimate least cost fuel options for the power sector, iii) input-output analysis to estimate economic impacts. The model results indicate that the mode of investment for climate change mitigation is a significant determinant of the impact on economic growth, incomes, and income distribution in India. In some scenarios, higher investments in green energy negatively affects low income households significantly more as compared to other households. The paper also demonstrates how the IMF can be used to determine the reasons for and therefore alleviate the negative impacts. Highlights • An Integrated Modeling Framework (IMF) combining three modeling methods is presented. • IMF built for India, but applicable for other developing countries also. • IMF useful to study balance between energy, environment, economy, and equity. • Negative trade-off between equity and renewable energy transition in some scenarios. • IMF useful for identifying ways to alleviate the negative trade-off. [ABSTRACT FROM AUTHOR]

Highlights • This paper presents enhanced modeling of gas network within planning models. • Solves the gas-electricity planning problem appling Dantzig-Wolfe decomposition. • Presents a scalable planning problem under long-term uncertainties. • Highlights the importance of multi-stage-stochastic gas-electricity planning problem. Abstract Planning networks within a multi-stage stochastic framework is becoming critical for improving the economic performance of investment decisions against the present levels of uncertainty. This problem, however, has been proved extremely challenging to be solved on real networks, especially when considering the interactions among various energy vectors. In this context, this paper proposes the use of Dantzig-Wolfe decomposition and parallel asynchronous column generation to solve a multi-stage stochastic planning of an integrated power and natural gas system, including non-linear effects of gas compressors reformulated in a mixed integer linear programming fashion. We compare the computational performance of the proposed approach against two alternatives: a parallel synchronous column generation approach and the counterfactual, monolithic approach, where the mixed integer linear program (without decomposition) is directly solved by a commercial solver. Our sources of long-term uncertainty are the locations and volumes of (i) new renewable generation (which may depend on policy objectives, regulatory incentives, etc. that are constantly evolving) and (ii) new demands. The model also ensures that the planned energy infrastructure can effectively be operated reliably against a large array of operating conditions originated by high variability of renewable generation outputs, multiple demand levels and hydro inflows. Through various case studies, we discuss and demonstrate the importance of stochastic and integrated planning of electricity and natural gas systems along with the benefits of asynchronous algorithms and decomposition techniques that can be parallelized. [ABSTRACT FROM AUTHOR]

Integrating electric vehicles (EVs) into the electric power system poses significant challenges to grid operation and planning due to the potential constraints on the power system. To minimize grid congestion, the best option is to increase the production of photovoltaic (PV) energy for domestic use and EV charging stations. This paper addresses the nexus of technical, financial, and environmental effects of customer involvement in economic development and load management. In this paper, a new model design of solar-powered EV charging stations is proposed and implemented in HOMER Grid, and a case study has explored how economic, technical, and energy management benefits can be achieved through customer energy involvement and the integration of PV-based charging stations. The proposed PV-based charging stations contribute toward the energy management of the region, and the study observes the real-time optimal charging and discharging strategy of PV-based grid-connected charging stations. The case study results show that the investigated area can produce 1,070,804.096 MWh/year of energy through maximum customer involvement, consequently reducing overall energy costs. Moreover, the study demonstrates that the selected region can produce 86,961,688 kWh/year through the PV system, achieving 363,899 charging sessions per year, offering maximum advantages and facilitation for EV charging. The proposed model applicability shows that large-scale customer involvement can bring significant techno-economic benefits and attract regional investments. • This paper proposes a new design of a grid-tied renewable energy system. • It investigates the energy economics and environmental effects for a practical location. • The research examines energy management including PV systems and electric vehicles. • The results of proposed model are compared with other models. [ABSTRACT FROM AUTHOR]

The production of electrical energy is always a substantial contributor to a country's economy; in particular, integrating renewable energy sources into the existing power system has tremendous techno-economic implications. However, the optimal penetration of renewables and dynamic loads management is highly complex while considering the multiple variables, time-varying characteristics, and operational uncertainties. This paper proposes a new model design of a grid-tied renewable system. It investigates energy economics and forecasts for the practical locality of the Muzaffarabad area in Azad Jammu and Kashmir. The proposed research examines the annualized energy estimation concerning varied customer PV system participation. The impact of consumer feedback on energy production is briefly examined. Various aspects, such as energy economics, including annual revenue generation, energy prices, and energy sell-back, are demonstrated in detail. The proposed study also looks at the connection between the rising usage of renewable energy and falling greenhouse gas emissions and energy prices. Moreover, it shows how customer input has altered energy economics via each district taking part in energy sharing. Also, it illustrates the relationship between energy bought and sold and how the grid and PV's share of energy interact. Based on the research study findings, PV systems can provide 61% of the total region's energy needs with maximum consumer involvement. The study found that when PV is integrated at a maximum level, grid energy purchases fall to 52%. Polluting gas emissions were reduced by 64% courtesy of the recommended approach, and energy cost was cut from $0.20 per kWh to $0.09 per kWh. The recommended system produces 81,635,608 dollars in revenue yearly and achieves a renewable part of 46.17% with the highest level of customer interaction. [Display omitted] • This paper proposes a new model design of a grid-tied renewable system. • It investigates the energy economics and forecasts for a practical location. • The research examines annualized energy estimation concerning PV systems. • The results of proposed model are compared with other models. [ABSTRACT FROM AUTHOR]

The European Union targets for 27% renewable energy share by 2030. At the same time, all new buildings should be nearly zero energy buildings from 2020 onwards. A major obstacle to these objectives is a combination of current economic stagnation and limited investors' confidence, which leads to low investment proportion. Despite many renewable energy technologies are already at a competitive level, the implementation rate in buildings is still low. In this paper, we focus on advances in efficient mechanisms to overcome non-technical barriers to the increase of renewable energy applications in buildings, such as Energy Performance Contracting (EPC). Tertiary sector holds a huge untapped potential for such applications, especially in Southern Europe. The Trust-EPC-South European initiative, implemented in six southern EU countries with a mix of beginner and intermediate energy service markets, aims at encouraging the financing of sustainable energy solutions in the tertiary sector, by creating a framework for standardization, assessment and benchmarking, thus improving trust and confidence in the financing parties. This paper presents three case studies in Greece, a Mediterranean family resort hotel, a resort and spa hotel and an office building. The installation of renewable energy measures, including photovoltaic systems, solar thermal systems and heat pumps, was examined and their EPC potential was rated, by using the described standardization and benchmarking methodology. Their economic savings range from 3 to 23% on yearly energy costs, at a discounted payback of 3–6 years, depending on the measure. A sensitivity analysis shows the impact of the variation of technical and economic parameters on the EPC projects feasibility. The standardization practice applied is expected to support the project actors in securing appropriate financing and eventually proceed with the renewable energy installations through the EPC. [ABSTRACT FROM AUTHOR]

This paper presents an assessment of the obstacles to the development of non-conventional renewable energy sources in Colombia. In the study, eleven barriers were included in three clusters: technical, social and economic. These barriers obstruct renewable energy sources from contributing to the electricity market in Colombia, mainly in its non-interconnected areas. The energy sources analysed are solar photovoltaic power, wind power, biomass, geothermal and small hydroelectric power (less than 20 MW electricity). Obstacles and energy alternatives are included in an assessment model by means of Analytical Network Process. The method permits ranking the barriers and energy sources according to their influence in the network. That means, the more conflictive the obstacles and the more obstructed the energy sources, the higher their values. Four experts participated in the procedure representing different stakeholders in the electricity market of Colombia. The research showed the most important barriers are costs of investment and operating, lack of public and private coordination and lack of development planning for renewable energy sources. The most influenced (hindered by barriers) sources are wind power and geothermal power. However, the experts did not fully agree on those results and differences are discussed. The paper ends with some recommendations for overcoming the main obstacles against the participation of renewable energy sources in the Colombian electricity market. [ABSTRACT FROM AUTHOR]

The development of cleaner and renewable energy sources are necessary so that fossil fuel dependency and global warming can be reduced. Present communication is an attempt to explore the available literature on Photovoltaic Thermal (PVT) air collectors and PVT air collector integrated greenhouse drying system. Solar drying is one of the best method to preserve crops for a long time. In developing and under developed countries; per capita electricity production is low; therefore the electricity uses for heating purpose cannot be economically and environmentally justified option. In previous studies, it was found that forced drying is better in terms of controlling drying parameters and PVT air collector is better than standalone PV module in terms of energy storage. In present review paper, combination of PVT air collector and drying system has been discussed. Moreover, thermal modelling of PVT air collector integrated greenhouse drying system has been presented in detail. Average thermal efficiency, electrical efficiency and overall thermal efficiency for PVT air collector are found to be 26.68%, 11.26% and 56.30% respectively at 0.01 kg/s mass flow rate of air. This review paper may be very helpful for researchers and scientists to develop thermal models for different hybrid solar systems. [ABSTRACT FROM AUTHOR]

Renewable energy generation represents a unique solution to ensure the sustainable development of society. However, its fluctuating nature can disturb the energy balance mechanism of the power grid. In microgrids powered by renewables, the issue is even more critical. Fossil fuel generation typically supplements renewables but storage and demand response can be more flexible and cost effective. This paper is an overview of recent undertakings that present storage and demand response techniques as solutions for the stable operation of renewable energy microgrids. The critical analysis of the recent papers in this area reveals that the parameters used for modeling storage have been simplified (efficiency, dynamic behavior at fast rate of discharge, aging…) and that the demand response incentives have been assumed to be enough for users to be willing to participate in demand response programs. These assumptions make the proposed solutions too inaccurate to be implemented on the field yet. If renewables have to be implemented on a large scale, specific and accurate models have to be used. By building on the current research presented here, much work can be converted into real advances in the field of renewable energy integration in microgrids. [ABSTRACT FROM AUTHOR]

This paper provides further arguments why Jacobson and Delucchi’s (JD) critiques of my paper are misplaced. It also provides additional references to work that reached different conclusions than Jacobson et al. Work by JD and others is useful in identifying the plethora of assumptions required to conclude that intermittent renewables can now be economically substituted for all current uses of fossil fuels throughout the entire economy. [ABSTRACT FROM AUTHOR]

Chinese electricity market has undergone twice reforms since 2002. However, the current electricity market is still partially irrational in electricity pricing mechanism. Furthermore, the utilization of renewable energy is inefficient in western regions. From the perspective of market participants, electricity retailers are new entrants in deregulated electricity market. In this spot electricity market, they are faced with various challenges and opportunities. Thus, this paper introduces an inter-regional power transaction model based on bottom-up modeling. There are mainly three parts in this paper: ⑴ It examines the existing problems and achievements in the twice reforms, and introduces the participants of cooperative game in a spot market. ⑵It proposes an inter-regional electricity transaction model to illustrate the new pricing mechanism. ⑶ Based on cooperative game theory, it quantifies how costs, electricity prices and benefits affect the behavior of retailers in a spot market with some reasonable economic assumptions. What is novel about this research is that the proposed transaction model analyzes electricity retailers' behaviors in a spot market. The cooperative game model improves electricity retailer's competitiveness in a spot market, and is of great theoretical and practical significance for the reform and development of China's electricity market. [ABSTRACT FROM AUTHOR]

Refrigerators are a common appliance in developed and emerging economies around the world. These appliances consume significant energy globally and improving their efficiency is an important aspect of future climate change mitigation. It is widely understood that the energy consumption of household refrigerating appliances is strongly influenced by room temperature and many analysts have identified ambient temperature as the most important factor in normal use. Room temperature has two main effects on the energy consumption of refrigerating appliances. Firstly, the temperature difference between the compartment and the room dictates the heat gain into the appliance through the wall insulation and door seals. A second effect is that a change in room temperature affects the condensing temperature. An increase in room temperature reduces overall refrigeration system efficiency by increasing the difference between the evaporating and condensing temperature. This paper examines laboratory data for 111 appliances where energy consumption is measured at four ambient temperatures from 10 °C to 40 °C. Field data for 235 appliances in homes is also examined. This is more complex to analyse, but it does provide useful information on underlying energy changes due to changes in room temperature during normal use. This paper determines the ratio of energy at 16–32 °C (energy conditions in IEC62552-3) and explores the shape of the energy curve at intermediate temperatures in order to develop a generalised energy curve as a function of temperature for the refrigerating appliances measured. The field data gave highly comparable shape data to that measured in the laboratory. The results provide a useful method to estimate the likely power consumption of different appliance types under a wide range of operating conditions, even where limited data is available. [ABSTRACT FROM AUTHOR]

Countries worldwide have set national targets for energy production from renewable sources. Yet, while many governments are committed to more renewable energy, obtaining permission to site installations is becoming increasingly difficult. With large tracts of land for renewables becoming intensely contested, countries seeking to meet their renewables targets are directing attention also towards tapping the potential in the urban environment through smaller-scale facilities. These entail other challenges, and countries are seeking ways to overcome them. The focus of this paper is on one, still evolving, type of renewable energy technology: small-scale wind turbines (SSWT). The paper presents a review of current but limited international academic knowledge on the land-regulation aspects of siting SSWT in countries that already have experience with such installations, including the USA, UK and New Zealand. The paper also reports on a comparative analysis of the land-related regulations and practices in two selected Mediterranean jurisdictions – Spain (Catalonia) and Israel. The approach of this study is exploratory, relying on analysis of legal and policy documents complemented by field work through in-depth interviews with key-stakeholders in both jurisdictions. The overall aim of this study is to examine different approaches of planning systems to new technologies. The findings show that despite their shared objective factors, the two jurisdictions have adopted almost opposite approach to regulating SSWTs. The findings, therefore, suggest that the incorporation of an unknown technology within the city requires a change of mindset both among the officials and among the city residents. A more effective regulatory framework might therefore entails a combination of strategic thinking, an experimental approach and the capacity to learn from cross-national comparative experiences. [ABSTRACT FROM AUTHOR]

[Display omitted] • PCM energy storage and PV/T coupled multi-source heat pump systems were combined. • The thermal performance, energy efficiency, and economy of the system were analyzed. • The performance of paraffin C17 and water as energy storage materials were compared. • The performance of six low-temperature PCMs applied to the system were analyzed. • Compared to the existing system, it saves 56 % of energy and 27.7 % of operating costs. To improve the application of renewable energy in the heating zone, as well as to address the limitations of air and water source heat pump. The study presents a PV/T (photovoltaic/thermal) coupled air–water source heat pump system integrated with phase change energy storage. A theoretical analytical model and TRNSYS simulation model of the system were developed to evaluate the thermal performance, energy efficiency and economics of the system. The performance of phase change energy storage was compared with that of water storage, and the effect of different phase change materials on the system characteristics. The results show that the coupled system achieves a seasonal performance factor of 2.3, a 56 % reduction in energy consumption, and a 27.7 % reduction in operating costs compared to a conventional gas boiler system. Comparative analysis with the water storage system showed that the system equipped with phase change materials performed well in terms of energy consumption, operating costs and heating stability. In addition, the density of the phase change material has a biased effect on the overall performance of the system. This paper can provide a reference value for the study of renewable energy heating systems in cold zone. [ABSTRACT FROM AUTHOR]

This paper finds that specific characteristics of bioenergy investments – namely long times to build, relatively high variable costs, and the managerial ability of corrective actions during the project – help bioenergy producers to respond to market uncertainties. This effect is shown to compromise the economic effectiveness of bioenergy policies. The paper compares the effectiveness of financial and regulatory incentive programs aiming to stimulate production of crop-based biogas. A stylized stochastic real-options based investment model is developed to analyze the investment behavior of biogas producers under alternative policies. The model is solved by a numerical approach combining stochastic simulations and the genetic algorithm technique. Unless bioenergy schemes account for structural characteristics of the bioenergy industry, they will tend to encourage investments in unused production capacities. This would cause additional welfare costs and benefit mainly crop producers. [ABSTRACT FROM AUTHOR]

Among the regulatory policies, feed-in tariffs (FIT) and renewable portfolio standards (RPS) are the most popular to promote the development of renewable energy power industry. This paper uses system dynamics (SD) to establish models of long-term development of the renewable energy power industry under FIT and RPS schemes, and provides a case study of China's wind power industry by using scenario analysis method. The model, on the one hand, not only clearly shows the complex logical relationship between the factors but also reveals the process of coordination between the two policy tools in the development of the renewable energy power industry. On the other hand, it provides a reference for scholars to study similar problems in different countries, thereby facilitating an understanding of the renewable energy power's long-term sustainable development pattern under FIT and RPS schemes, and helping to provide references for policy-making institutions. The results show that the integrate implementation of FIT and RPS can promote long-term and rapid development of China's wind power industry given the constraints and actions of the mechanisms of RPS quota proportion, the tradable green certificates (TGC) valid period, and fines. In addition, in the period of the construction of the TGC market, RPS quota growth rate and fine have a no significant effect on industrial development, however, with TGC market game becoming more and more fierce, both of them have a significant positive impact on the long-term development of the industry. TGC valid period has little effect on industrial development in our study. At the end of the paper, policy implications are offered as references for the government. [ABSTRACT FROM AUTHOR]

This paper presents a novel research work on the potential benefits of using, a unique and sustainable energy source - the human-power. The paper discusses the benefits and the practicality of using human-power as a domestic energy source to power electrical and electronic devices and explores the benefit of its use in a more diverse perspective for possible change in behaviour and energy savings for improved sustainability in the society. The economic and sustainability gains of using Human-Powered Products (HPPs) are investigated. Two studies have been conducted, the first is a study which involves assessing the environmental impact of a human-powered products via Life Cycle Assessment (LCA); and the second is a case study called Home User Study (HUS), where the technology is experimentally tested. The human-powered system is used to explore the real benefits and life-cycle analysis towards assessing the sustainability of such products. The Home User Study (HUS) has been conducted to explore the in-situ use of human-powered systems using a new prototype that has been built and deployed. The study has used a monitoring device to measure the outcome of the interaction between the user and human-powered products. The results interestingly have revealed various other forms of benefits beyond renewable energy that could add extra motives for using human-powered products, such as health benefits. The paper also puts an emphasis on the opportunity of using Human-Powered Products which can be perceived as a great viable solution against counter measuring social issues such as physical inactivity and increasing sedentary behaviour. The results of the theoretical study indicate that Human-Powered Products (HPP) do not offer significant financial savings. The results of the HUS indicate that using human-powered products for health prospective outweigh the benefit gained from the prospective of energy savings and renewable energy. Based on the findings of this study, the paper suggests an approach that shows how the implementation of Human-powered systems could provide the opportunity to sustainable energy generation and energy savings, but in all cases they can be retained through a motivational drive in improving the health benefit via encouraging physical activities. [ABSTRACT FROM AUTHOR]

As an important energy base of China, Xinjiang is the key part of the “Silk Road” economic belt development strategy and is in an superior position. This paper analyzes the problems exist in the sustainable energy industry based on the distribution status of sustainable resources of Xinjiang. The evaluation index system of the application level of Renewable Energy Systems (RESs) is discussed using the wind farm as an example. Besides it investigates the advantages and disadvantages of the development process of each node in the “Silk Road” economic belt areas according to the current situation of the resources, economic and social development. Suggestions for the development of each area are proposed in the end. This paper will contribute to the sustainable development of renewable energy industry and economy in Xinjiang. [ABSTRACT FROM AUTHOR]

The increasing greenhouse gas (GHG) emission and environmental degradation (ED) is a serious concern for the various economies, and a similar issue is observed in Asia. This paper investigated the role of clean energy from renewable sources, urbanization, and economic growth in determining the level of GHG emissions from 1995 to 2018 for ten Asian States through a cross-sectional autoregressive distributed lagged (CS-ARDL) model. Meanwhile, the current research also examined the cross-sectional dependence, unit root properties, and co-integration between the study variables. The study findings confirmed that clean energy and GDP2 played their constructive role in reducing GHG emissions in the natural environment or targeted economies. In contrast, urbanization and economic growth caused more GHG emissions both in the long and short run. Furthermore, the robust check through augmented mean group (AMG) and common correlated effect means group (CCEMG) also confirmed that clean energy and GDP2 have a good sign for lowering ED compared to GDP and urbanization. The study findings could support policymakers, specifically in the field of energy economics and environmental sustainability. Therefore, it is highly recommended that some strong policy implications are needed to reduce environmental issues through controlling the negative impact of economic growth and urbanization. This study contributes in the literature of GHG emission with respect to economic growth, urbanization and clean energy and guided the regulators while formulating policies related to control the GHG emission. • The increasing GHG emission is a serious concern for the various economies. • We examined the clean energy, urbanization and economic growth impact on GHG emissions. • We examined cross-sectional dependence, unit root and cointegration among variables. • Clean energy plays constructive role in reducing GHG emissions in natural environment. • Urbanization and economic growth caused more GHG emissions in long and short run. [ABSTRACT FROM AUTHOR]

Lack of reliable data often prevents new private investments in renewable energy and government programs in this sphere. The paper offers a novel renewable energy resources system of potentials: energy, resource saving and environmental; better designed and more accurate methods for calculating the future exploitable technical potentials of wind and solar PV energy for a wide range of generating equipment in centralized and distributed power systems, taking into account existing social and environmental limitations. The paper also presents the latest assessments of these potentials for Russia and its 85 regions (in terms of fossil fuel saving and substitution, power and heat production and environmental effects), offering solutions to overcome methodological limitations of previous country-level assessments, such as incomplete or unreliable sources, absence of hourly, daily and monthly assessments, etc. Given the limitations of existing network of national meteorological stations and satellite monitoring systems it was decided to use NASA SSE database as a source of meteorological information. The methodology was validated through a comparative analysis of the data obtained in the course of this study and the data of wind monitoring campaign carried out by a German engineering company in one Russia's region for 18 months using 70 m masts. [ABSTRACT FROM AUTHOR]

System inertia reduction, driven by the integration of renewables, imposes significant challenges on the primary frequency control. Electrification of road transport not only reduces carbon emission by shifting from fossil fuel consumption to cleaner electricity consumption, but also potentially provide flexibility to facilitate the integration of renewables, such as supporting primary frequency control. In this context, this paper develops a techno-economic evaluation framework to quantify the challenges on primary frequency control and assess the benefits of EVs in providing primary frequency response. A simplified GB power system dynamic model is used to analyze the impact of declining system inertia on the primary frequency control and the technical potential of primary frequency response provision from EVs. Furthermore, an advanced stochastic system scheduling tool with explicitly modeling of inertia reduction effect is applied to assess the cost and emission driven by primary frequency control as well as the benefits of EVs in providing primary frequency response under two representative GB 2030 system scenarios. This paper also identifies the synergy between PFR provision from EVs and “smart charging” strategy as well as the impact of synthetic inertia from wind turbines. [ABSTRACT FROM AUTHOR]

This paper is to assess the current trend, implementation and future possibilities of solar home systems (SHS) at the non-electricity provided study area in Bangladesh. The study also suggests an applicable plan to solve the problems and assure the proper availability and using compatibility of SHS to the poor and helpless rural people. The study area of the research is Lechraganj Char Union, Harirampur subdistrict of Manikganj district in Bangladesh. The trends and implementation strategies of solar home system (SHS) would be available in the Section 3.1 and Section 3.2 ; the future possibilities described in the Section 4 . One of the major rational of this research is to provide a sample plan of SHS implementations, future propagation process, prospects and issues to be solved can be useful for the whole non grid zones of the country Bangladesh. This could bring more country progress by renewable technology and the lower order citizens of the country by the supply of electricity and also future analysis of SHS. The primary data sources to shape the paper were- personal field observation, field documentation, taking photographs, qualitative household survey, household questionnaire survey, in-depth interview, FGD etc. Secondary data sources were from different books, articles, journals, magazines, newspaper, Government and NGO Organizations, unpublished reports and thesis etc. Various cartographic techniques as like- Produced tables, flow charts, pie-diagrams, graphs, histograms were used for both qualitative and quantitative analysis of implementation of SHS in Harirampur Subdistrict. Proper direction by the government authority and NGOs can improve the current condition and support the off grid citizens of Bangladesh for the penetrating them under the coverage of SHS technology.Further assessment on the implementation of SHS, quality of SHS devices, environmental impacts of SHS, detailed economic advantages can be done for the proper expansion of SHS. [ABSTRACT FROM AUTHOR]

Accurate estimation of extreme wave conditions is critical for offshore renewable energy activities and applications. Wave power is the transport of energy by wind waves, and the capture of that energy to do useful work. Wave energy converter (WEC) devices are designed to sustain the wave-induced loads that they experience during both operational and survival sea states. The extreme values of these forces are often a key cost driver for WEC designs. These extreme loads often occur during severe storms; therefore careful examination of harsh wave conditions during the device design process is needed. Consequently the development of a specific extreme condition modeling method is essential. This paper presents a novel method for estimating extreme wave statistics, based on the hourly measured wave height maxima at the location of interest. Wave measurements, analyzed in this paper, were collected at SEM-REV offshore sea station located near the coast of France, during years 2001–2010. Note that applied statistical methodology is general and can be well applied to a measured WEC response, and its technology risk assessment. Accurate estimation of extreme wave conditions is critical for offshore renewable energy activities and applications. SEM-REV is known French wave energy test site. The method, referred to as ACER method, is presented in brief detail. ACER method provides an accurate extreme value prediction, utilizing available data efficiently. In this study the estimated return level values, obtained by ACER method, are compared to the corresponding return level values obtained by Gumbel method. Based on the overall performance of the proposed method, it is concluded that the ACER method can provide a robust and accurate prediction of extreme wave height at a given location. [ABSTRACT FROM AUTHOR]

Excessive energy consumption and carbon dioxide emissions are long lasting issues and need continuous research to improve efficiency evaluation and performance monitoring of economies. The static and dynamic aspects of efficiency need to be dealt with simultaneously to thoroughly analyze the performance of economies. This paper aims at conducting a static and dynamic analysis of energy and CO 2 emissions efficiency of major economies. In this paper, we applied slacks based model of Tone (2001) with the treatment of undesirable output in objective function and constraint assuming free disposability of undesirable output and built a dashboard. The results can be summarized by saying that the larger economies with intensive production strategy, larger secondary industry, and weaker carbon tax laws are more likely to be inefficient. China, India, and Russia have the greatest potential for improvement in both energy efficiency and carbon dioxide emissions efficiency. The suggested dashboard has the ability to dig out the potential for efficiency improvement of countries like the USA, which mostly appear at the efficient frontier with other techniques. Concluding it can be suggested that economies in lower ranks of dashboard need stricter policy measures to cut energy consumption, carbon dioxide emissions and encourage a shift from fossil fuels to other renewable resources of energy. [ABSTRACT FROM AUTHOR]

Organic Rankine cycles (ORC) are becoming a major research area within the field of sustainable energy systems. However, a major challenge facing the widespread implementation of small and mini-scale ORC systems is the economy-of-scale. To overcome this challenge requires single components that can be manufactured in large volumes and then implemented into a wide variety of different applications where the heat source conditions may vary. The aim of this paper is to investigate whether working fluid selection can improve the current economy-of-scale by enabling the same system components to be used in multiple ORC systems. This is done through coupling analysis and optimisation of the energy process, with a performance map for a small-scale ORC radial turbine. The performance map, obtained using CFD, is adapted to account for additional loss mechanisms not accounted for in the original CFD simulation before being non-dimensionalised using a modified similitude theory developed for subsonic ORC turbines. The updated performance map is then implemented into a thermodynamic model, enabling the construction of a single performance contour that displays the range of heat source conditions that can be accommodated by the existing turbine whilst using a particular working fluid. Constructing this performance map for a range of working fluids, this paper demonstrates that through selecting a suitable working fluid, the same turbine can efficiently utilise heat sources between 360 and 400 K, with mass flow rates ranging between 0.5 and 2.75 kg/s respectively. This corresponds to using the same turbine in ORC applications where the heat available ranges between 50 and 380 kW th , with the resulting net power produced by the ORC system ranging between 2 and 30 kW. Further investigations also suggest that the same pump could also be used; however, the heat exchanger area scales directly with increasing heat input. Overall, this paper demonstrates that through the optimal selection of the working fluid, the same turbomachinery components (i.e. pump and turbine) can be used in multiple ORC systems. This offers an opportunity to improve the current economy-of-scale of small ORC systems, ultimately leading to more economical systems for the utilisation of low temperature sustainable heat sources. [ABSTRACT FROM AUTHOR]

This paper investigates the impact of the inter-regional transmission grid capacity expansion on China’s power sector decarbonization from the energy portfolio, economic efficiency and environmental perspectives. The impact is quantified based on a cluster integer unit commitment model which renders it suitable for modeling large-scale power systems with a high computational performance. The results show that, first, the inter-regional transmission grid capacity expansion has obvious economic benefit in reducing the total variable generation costs, mainly due to the increased ability of transmitting coal power with low marginal generation costs and the reduction in non-served load. Second, the expansion has a very limited impact on reducing the curtailment of renewable generation by 2030, although the extent to which the expansion can mitigate the curtailment of renewable generation increases with the share of renewable power in the generation portfolio. Third, the expansion increases CO 2 emissions of the power supply in 2030 by around 2%, mainly because it facilitates more use of cheap yet low-efficiency coal generation in regions with low fuel prices. To better deliver the value of the inter-regional grid expansion for China’s power decarbonization, this paper proposes that: (1) the planning of the inter-regional and intra-regional grid development should be coordinated with the renewable power development; and (2) effective dispatch mechanisms which account for CO 2 emissions or generation efficiency across regions should be established. Additionally, the government plan of the inter-regional transmission capacity in 2030 is basically sufficient in enabling bulk power delivery and promoting renewable generation across regions. [ABSTRACT FROM AUTHOR]

The recent trend in high penetration of renewable energy will lead to a significant mix of renewable technologies in the future power industry portfolio. One important inconvenience of these technologies is their intermittency of power generation. This variability of energy production leads to an increased need of services such as reliability, regulation and transmission congestion. In order to make the electric grid reliable and efficient, system operators have to deploy cost-effective ways to balance supply and demand in real time. Energy storage is considered a viable solution and can mitigate several problems. However, it is still unclear whether or not energy storage will generate enough profit by interacting with energy and ancillary markets. Current economic studies on the energy storage technologies are limited because they do not explore possibilities of using storage in arbitrage and ancillary services in both day-ahead and real time markets. This paper focuses on the economics of energy storage participating in arbitrage and regulation services within different markets. A case study on gravity storage system is used to verify the effectiveness of the proposed operation optimization model. Finally, this paper discusses the value of storage in various grid applications. [ABSTRACT FROM AUTHOR]

This paper analyzes the optimal planning and operation of aggregated distributed energy resources (DER) with participation in the electricity market. Aggregators manage their portfolio of resources in order to obtain the maximum benefit from the grid, while participating in the day-ahead wholesale electricity market. The goal of this paper is to propose a model for aggregated DER systems planning, considering its participation in the electricity market and its impact on the market price. The results are the optimal planning and management of DER systems, and the appropriate energy transactions for the aggregator in the wholesale day-ahead market according to the size of its aggregated resources. A price-maker approach based on representing the market competitors with residual demand curves is followed, and the impact on the price is assessed to help in the decision of using price-maker or price-taker approaches depending on the size of the aggregated resources. A deterministic programming problem with two case studies (the average scenario and the most likely scenario from the stochastic ones), and a stochastic one with a case study to account for the market uncertainty are described. For both models, market scenarios have been built from historical data of the Spanish system. The results suggest that when the aggregated resources have enough size to follow a price-maker approach and the uncertainty of the markets is considered in the planning process, the DER systems can achieve up to 50% extra economic benefits, depending on the market share, compared with a non-aggregated business-as-usual approach (not implementing DER systems). [ABSTRACT FROM AUTHOR]

Solar home systems (SHSs) are the real hope for electrification of the off-grid areas in Bangladesh by utilizing the solar energy in renewable and sustainable basis. This paper demonstrates the solar energy prospect, the present status and dissemination schemes of SHSs in off-grid and coastal areas of Bangladesh by several government and Non-government organizations (NGOs). The country has an average daily solar radiation ranges between 4–6.5 kWh/m 2 . Currently, more than 3.8 million SHSs of capacity range 10–135 Wp (watt peak) with a total capacity of 150 MW have been disseminated in rural and isolated areas in Bangladesh. In this paper, ten case studies of capacity 20 Wp, 30 Wp and 42 Wp were investigated to evaluate economic viability at two randomly selected villages in Sirajgonj district and Jessore district, Bangladesh. The analysis showed that the SHSs for small business enterprise and household with small income generation are economically viable rather than only household lighting. [ABSTRACT FROM AUTHOR]

The scarcity of natural resources and the growing need for electricity requires the development of new technologies that can provide alternatives to traditional energy sources in a sustainable fashion. One of the promising opportunities currently under development is Microbial Fuel Cell (MFC) technology. The aim of our study was to analyze the relevant literature related to MFCs through a scientometric approach in order to produce a comprehensive synthesis, something that is lacking. We identified 19671 relevant studies in the field and examined 3427 papers in detail in a systematic review performed in the ISI database Web of Science. Our primary goals were to: (i) determine the temporal evolution of publications, (ii) reveal which journals publish on the subject, (iii) show the global distribution of MFC research and funding perspectives, (iv) uncover the scales of application of the technology, (v) account for the most commonly used substrates, (vi) find out whether pure or mixed cultures of microorganisms are involved and (vii) determine the major species used. We detected a substantial increase in publications after 2006. We found that the US and East Asia are the most promising locations for the development of MFCs, given both the number of publications and the amount of financial investment in research and development. The main technological barrier to the wide-spread use of MFCs is the scale of application, restricted to small prototypes insufficient to generate electricity for practical purposes. The most cited substrate was wastewater, both domestic and industrial, demonstrating the great potential of MFCs in wastewater treatment. Finally, our results demonstrated that there is a wide variety of microorganisms capable of generating electricity, although the great majority of papers focus on a few well-established species. Taken together, our results can help research and application in this field on a global level perspective. [ABSTRACT FROM AUTHOR]

Iran's energy system is extremely dependent on fossil fuels which, in turn, have led to problems such as fossil fuels depletion, social, economic and environmental damage and territorial imbalance. The country should therefore design a sustainable energy system based on clean energy a s well as renewable energy. Accordingly, and given that Iran's rural areas suffer from the unsustainable energy system, it is necessary to integrate renewable energy into comprehensive development programs in general, and into rural development programs, specifically. This review paper answers the following questions: Why is renewable energy important for Iran at national and rural levels? How is renewable energy related to sustainable rural development? and What are the challenges in the promotion of renewable energy technologies in Iran? The paper concludes that although renewable energy has potential for development in Iran's rural areas due to environmental, social and economic advantages, it could face some infrastructural, managerial, socio-cultural and economic challenges. Accordingly, aggressive and innovative policy making is required to meet these challenges. [ABSTRACT FROM AUTHOR]

Energy crisis and high emission of fossil fuels are major driving forces for developing renewable energy based technologies. In order to meet growing demand for energy, hydropower can be one of the sustainable alternatives. Further, the hydrokinetic turbine is considered as one of the most emerging technologies which harness energy from flowing water. In this paper, an attempt has been made to review hydrokinetic energy theory for energy conversion system from water currents analogous to wind power system. The most widespread classes of hydrokinetic turbines are discussed in detail with respect to their benefits, drawbacks and desirable conditions for applications. It has been found that in spite of some prevailing downsides of vertical axis turbine like of self-starting and lower efficiency, vertical axis turbines are appealing for many riverine applications. One of the prominent turbines of its kind is the Savonius hydrokinetic turbine that has the capacity to self-start at a very low fluid velocity in the river, canal etc. However, Savonius type hydrokinetic turbine inherently has poor efficiency. A number of experimental and numerical studies with a large number of physical designs and parameters have been carried out in the area of Savonius rotor to enhance its efficiency. Under this study, review of different parameters affecting the performance of Savonius hydrokinetic turbine has been carried out and presented in this paper which may be useful for future studies to improve the efficiency of such turbines. [ABSTRACT FROM AUTHOR]

The economic assessment of low-carbon energy options is the primary step towards the design of policy portfolios to foster the green energy economy. However, today these assessments often fall short of including important determinants of the overall cost-benefit balance of such options by not including indirect costs and benefits, even though these can be game-changing. This is often due to the lack of adequate methodologies. The purpose of this paper is to provide a comprehensive account of the key methodological challenges to the assessment of the multiple impacts of energy options, and an initial menu of potential solutions to address these challenges. The paper first provides evidence for the importance of the multiple impacts of energy actions in the assessment of low-carbon options. The paper identifies a few key challenges to the evaluation of the co-impacts of low-carbon options and demonstrates that these are more complex for co-impacts than for the direct ones. Such challenges include several layers of additionality, high context dependency, and accounting for distributional effects. The paper continues by identifying the key challenges to the aggregation of multiple impacts including the risks of overcounting while taking into account the multitude of interactions among the various co-impacts. The paper proposes an analytical framework that can help address these and frame a systematic assessment of the multiple impacts. [ABSTRACT FROM AUTHOR]

Energy efficiency policies play a key role in the transformation to a ‘green energy economy’. In this paper, we take stock of the impacts of the existing energy efficiency policy instruments in Germany and review the energy, environmental and socioeconomic impacts of the country’s latest energy efficiency and climate strategies for the year 2020. We find evidence supporting the findings of other studies that enhanced green energy policies will trigger tangible economic benefits in terms of GDP growth and new jobs even in the short term. Whereas policy makers have already acknowledged and implemented this conclusion in the case of renewable energies, our paper shows that striving for more ambitious energy efficiency policies represents a similar win–win strategy, which should be exploited to a much larger extent. [ABSTRACT FROM AUTHOR]

Promoting energy efficiency is one of the top priorities of the EU energy strategy. Manufacturing is identified there as one of the sectors holding the potential for substantial energy efficiency improvements. This paper therefore examines factors impacting firms' decisions to invest in energy efficiency and clean technologies. Drawing on the energy efficiency gap literature, the impact of three groups of factors is analysed, namely economic (firm-specific characteristics and market drivers), organisational, and regulatory. Employing probit and bivariate probit models on a panel data set for 848 Slovenian manufacturing firms over 7 years (2005–2011), the paper finds that decisions to invest in energy efficiency and in clean technologies are impacted by similar, yet not identical factors. The following factors significantly increase the likelihood of both energy efficiency and clean technology investments: share of energy costs, market share, and export orientation. Importantly, other types of investments (except for investments in the expansion of existing capacities) do not crowd-out energy efficiency or clean technology investments. On the other hand, foreign ownership and managers' expectations of future demand only impact energy efficiency investments, while clean technology investments are influenced by managers' expectations of the future business condition of the firm. Further, the economic and financial crisis reduces the likelihood of clean technology investments, but not energy efficiency investments. This is explained by the fact that investments in energy efficiency represent a cost-effective solution for the firm. The same argumentation can be used to explain why high energy costs also play an important role for investments in clean technology. In addition, the likelihood to invest is found to be importantly influenced by industry-specific characteristics, which captures the effect of industry differences in environmental regulation and other conditions. The paper adds to the existing literature in three important ways: it employs data on actual rather than intended investments; it examines investment decisions over a number of years, thereby allowing for an analysis of the impact of the recession on firms' decisions; and it examines relationships among different types of investments, accounting for a potential crowding-out effect. Based on the paper's findings, it can be concluded that the energy efficiency gap is less likely to exist in large and well-performing firms, implying that policy measures should primarily target less energy intensive, small and medium-sized enterprises. [ABSTRACT FROM AUTHOR]

In this paper, a stochastic self-scheduling of renewable energy sources (RESs) considering compressed air energy storage (CAES) in the presence of a demand response program (DRP) is proposed. RESs include wind turbine (WT) and photovoltaic (PV) system. Other energy sources are thermal units and CAES. The time-of-use (TOU) rate of DRP is considered in this paper. This DRP shifts the percentage of load from the expensive period to the cheap one in order to flatten the load curve and minimize the operation cost, consequently. The proposed objective function includes minimizing the operation costs of thermal unit and CAES, considering technical and physical constraints. The proposed model is formulated as mixed integer linear programming (MILP) and it is been solved using General Algebraic Modeling System (GAMS) optimization package. Furthermore, CAES and DRP are incorporated in the stochastic self-scheduling problem by a decision maker to reduce the expected operation cost. Meanwhile, the uncertainty models of market price, load, wind speed, temperature and irradiance are considered in the formulation. Finally, to assess the effects of DRP and CAES on self-scheduling problem, four case studies are utilized, and significant results were obtained, which indicate the validity of the proposed stochastic program. [ABSTRACT FROM AUTHOR]

Renewable energy sources have a huge potential to reduce greenhouse gas emissions and decrease the dependence on fossil fuels in the energy sector. However, the energy output of these sources is variable and raises concerns regarding the electric grid reliability. Therefore, the deployment of energy storage would play a key role in enabling the integration of these sources in the electric grid. This paper proposes methods for determining the optimal operation and sizing of energy storage systems. The main purpose of the operation strategy is to maximize the revenues of the renewable farm. The sizing model, on the other hand, has a purpose to minimize the cost of the hybrid system while meeting the service requirement. Both methods were formulated as non-linear programming optimization models. To verify the effectiveness of these methods; case studies have been presented. Finally, this paper proposes an economical analysis to determine the cost added by the storage to each KWh of stored energy. [ABSTRACT FROM AUTHOR]

As one of the most cost-effective means of emission reduction, carbon tax has attracted considerable attention from economists and international organizations and has led to a large number of related research. Using the bibliometric method, this paper characterizes the carbon tax literature from 1989 to 2014 based on the Network Database Platform of Web of Science. The results indicate that the USA occupies a leading position in the carbon tax field. The Vrije University Amsterdam, Massachusetts Institute of Technology and Stanford University were the most productive research institutes. Energy Policy (143) has been the most productive journal followed by Energy Economics (44) and Energy (38). In general, the cooperation of authors, institutes and nations are continuing to strengthen; however, the growth rate at the author level was significantly higher than the others. In addition, the current key research areas in the carbon tax field based on Co-Keyword Analysis are as follows: climate change and relevant policy, carbon emissions trading, socio-economic effects of carbon tax, renewable energy, endogenous technological change and carbon capture and storage. The results of this paper will help researchers grasp the current research in the carbon tax field but also provide a supporting role for future work. [ABSTRACT FROM AUTHOR]

Improvement of thermal performance of a solar air heater can be obtained by enhancing the rate of heat transfer. Thermal efficiency of matrix solar air heater is higher in comparison to conventional type. Number of studies has been reported in the literature on the performance of matrix air heater with different material packing and elaborated various parameters such as design; heat transfer enhancement, flow phenomenon and pressure drop in the duct. Majority of the studies revealed an increase in the thermal efficiency for matrix collector as compared to conventional plane solar air heater. This review paper presents an extensive study of the research carried out on matrix solar air heater. Based on literature review, it is concluded that the solar air heaters performed well when packed with porous medium and this is due to the geometrical parameters of porous material. In addition double pass porous bed solar air heaters performed better than single pass. Various types of matrix materials used in the literature and correlations developed for heat transfer and friction factor by different researchers have been presented. Much attention has been devoted in this paper to portrait the development of various types of solar air heaters over the years. The merits and demerits of different models evolved by many researchers have been critically analyzed. Finding in a nut shell is that the drawbacks associated with conventional nonporous solar air heaters such as high heat loss to the ambient, decreased convective heat flow from plate to air, etc. can be overcome by the use of an effective design of porous bed solar air heater. [ABSTRACT FROM AUTHOR]

Following the 2005 Kyoto protocol, developed countries made commitments to reduce the emission of greenhouse gases, mostly by integrating renewable energy technologies into their power production systems. It is a more challenging procedure for third world countries, including Lebanon, that have limited means and potential to achieve such goals. This paper assesses the status of renewable energy systems in developing countries, and concentrates on the solar photovoltaic energy production due to its abundant availability in these countries relatively to other clean energy production methods. Comparisons of developing countries׳ achievements and goals each according to their economical, political and social considerations are conducted. Projects ranging from small scale standalone systems such as microgrids and minigrids to large scale energy production stations will be presented by dividing the countries into categories that share similar constraints and limitations in the integration of such installations. Furthermore, the paper analyzes the state of energy generation based on photovoltaic systems in Lebanon in contrast to other developing countries. [ABSTRACT FROM AUTHOR]

Pakistan is among the 10 countries that face the worst energy crisis of the world. As the country struggles with a number of financial, political and social issues, the transition from a conventional fuels based economy to a green economy is not an easy one. Pakistan has been blessed with immense potential of clean renewable sources of solar, wind and biomass but they have not been exploited yet. Renewable energy technology sector has not penetrated the energy mix and is currently an emerging market. This paper highlights the steps the country has taken in the past and the steps that are being taken at present to emerge out of the prevailing energy crisis when even the most urban areas suffer from power outages of 12 h per day. Until 2009, no single grid interconnected wind farm existed but now the situation has changed considerably and wind farms contributing to the national grid are a reality now. Three grid interconnected farms have been inaugurated and many others are in pipeline. The national policy regarding wind power systems has recently changed after unexpected setbacks to ongoing projects. This paper reviews the developments in the wind power sector of the country and lists some suggestions that can help improve the wind power penetration in the national energy mix. [ABSTRACT FROM AUTHOR]

Given that the first industrial revolution was based on Steam Engine (coal as energy source), and the second on oil and electricity, where both these revolutions are actually "high carbon" revolutions, it is logical to expect that the third industrial revolution should be based on systems of renewable energy sources (RES), in order to minimize the problems arising from climate changes and to achieve sustainable development. However, the usage of the RES technologies and daily/weekly storage of energy and their connection to smart grids is not enough for the expected third industrial revolution. The start of this revolution would require technologies that have a great potential for further development and ability to supply, at any time, the necessary energy and power to a settlement/city, as well as drinking water, meeting the peak load requirements, continuously throughout the year, and independently of external sources of energy and drinking water. This would be provided from intermittent RES energy (solar, wind, etc.) and sea or other unclean source of water as natural resources. In that context, this paper presents a radically new technological solution: Key Engine which uses only natural resources: the sun, sea and gravity, in order to continuously and simultaneously supply a consumer with energy, power and drinking water. This solution has all the essential features required to start a third industrial revolution. The basic unit of Key Engine consists of the solar thermal (ST) generator with parabolic trough collectors through which sea water flows directly, absorbing thermal energy of solar radiation. After the separation of steam from seawater, the steam drives turbines and generators and produces electricity that is delivered to Pump Storage Hydroelectric (PSH) facility with seawater, which balances the daily and seasonal surpluses and shortages of energy, thus ensuring a continuous supply of electric power and energy to a consumer. At the same time, the water that comes out of the turbine, passes through the water treatment unit and is stored in drinking water reservoir, enabling continuous supply of the same consumer with drinking water. The paper presents theoretical aspects of Key Engine, model for optimal sizing and practical formulas for the calculation of characteristic values of the system, which could be the basis for further scientific research, development and innovative solutions that would help engineers in practice for numerous and diverse applications of Key Engine. In order to verify the derived mathematical relationships and models for optimizing the Key Engine in real conditions, the case study of the island of Vis in the Adriatic Sea, Croatia, has been considered, along with total annual irradiance of 1575 kW h/m 2 a, total annual electric energy consumption of 20 GW h and drinking water consumption of 453,382 m 3 . The obtained results: power of ST generator of 52 MW, working volume of the upper reservoir of 7 hm 3 , total annual electric energy production of 62 GW h/a, and drinking water production of 480,754 m 3 /a, clearly show that the new technology can fully meet the needs of the considered consumer for energy and drinking water. As the basic idea of Key Engine relies on the use of natural resources, i.e. RES energy and sea, the paper presents only the starting solution, whereby, apart from the sun, RES can be wind, or other renewable sources, that can perform separation of vapor from seawater and thus produce drinking water, as well as energy simultanously. Also, energy storage may not be performed solely by the PSH technology, but also by any other technology that can provide seasonal balancing of energy. All this suggests that the Key Engine can be understood as an open-source for RES technology development and thus bring changes in all three aspects of sustainable development: economy, society and environment. [ABSTRACT FROM AUTHOR]

Renewable energy not only can effectively alleviate the depletion of traditional energy sources, but also meet the need for building development. At present, the applications of renewable energy in buildings are still facing many problems. This paper presents a review of the application of renewable energy systems in buildings, and describes how to make good use of renewable energy for the sustainable development in the hot-summer and warm-winter region of China. The effective measures would improve the calculation methods, design the building and energy system with locality, develop integrated design of renewable energy systems, establish evaluation indexes of renewable energy applicability in buildings, and strengthen project management. Discussion results presented in the paper can provide a guideline for better to apply renewable energy systems to buildings in the hot-summer and warm-winter region of China. [ABSTRACT FROM AUTHOR]

Energy is the foundation of modern economies and the central need for modern life. It is a prerequisite for economic growth, improving living conditions and alleviating poverty. Therefore, access to energy is considered an important development goal. Obstacles such as high energy costs, unaffordable energy grid infrastructure and disperse population makes providing access to a majority of the world's population in developing countries a daunting task. Meanwhile, renewable energy technologies offer a unique opportunity to provide affordable and sustainable energy to millions of people. Renewable energy technologies, in particular, offer diverse and economically attractive options for rural electrification. This paper evaluates the economic and social impacts of community based renewable energy (CRE) projects on towns and communities. It investigates whether implementing such programs lead to considerable improvements in economic and social conditions of targeted communities and provide a sustainable energy solution. Relevant literature was reviewed and a comprehensive survey was developed to collect data from two towns in Afghanistan where renewable energy based electrification projects were implemented. Initial research findings provide strong indications that renewable energy projects are linked to improvements in economic conditions of the two pilot towns; both at the town and household levels. This research finds that economic impacts of CRE projects are rather modest as they lead to limited improvement in job creation and flourishing of businesses. Finally, CRE projects are found to be responsible for improving on sustainable supply of energy to the targeted communities. Policy makers and planners can use the findings of this paper as a guide to develop alternative sustainable solutions for energy production while using them as a tool for development of the recipient communities. [ABSTRACT FROM AUTHOR]

Introduction of renewable energy sources (RES) in insular areas is growing on different islands of various regions in the world and the large-scale deployment of renewables in island power systems is appealing to local attention of grid operators as a method to decrease fossil fuel consumption. Planning a grid based on renewable power plants (RPP) presents serious challenges to the normal operation of a power system, precisely on voltage and frequency stability. Despite of its inherent problems, there is a consensus that in near future the RES could supply most of local needs without depending exclusively on fossil fuels. In previous grid code compliance, wind turbines did not required services to support grid operation. Thus, in order to shift to large-scale integration of renewables, the insular grid code ought to incorporate a new set of requirements with the intention of regulating the inclusion of these services. Hence, this paper discusses grid code requirements for large-scale integration of renewables in an island context, as a new contribution to earlier studies. The current trends on grid code formulation, towards an improved integration of distributed renewable resources in island power systems, are addressed. The paper also discusses advanced grid code requirement concepts such as virtual wind inertia and synthetic inertia for improving regulation capability of wind farms and the application of energy storage systems (EES) for enhancing renewable generation integration. Finally, a comparative analysis of insular grid code compliance to these requirements is presented in the European context. [ABSTRACT FROM AUTHOR]