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As the solar energy utilization technology for renewable clean energy, actual parabolic trough receivers are subject to tracking errors and absorber tube installation errors, and the bellows and Kovar ring under these errors have a significant impact on the receiver's safety. Based on the MCRT-FVM-FEM principles in this paper, a receiver's optical-thermal-stress mathematical model is modeled and the thermal-stress performance and safety of the receiver's key components under two errors are evaluated. The correlation between the bellows and Kovar ring's performance and the two errors is analyzed. The results demonstrate that the lower tracking errors and larger installation errors markedly increment the absorber's deformation and have a negative impact on the receiver safety. Bellows and Kovar ring's asymmetrical temperature distribution causes variable swell and uneven stress under tracking and installation errors. Temperature gradient variation of bellows is more sensitive under errors than Kovar rings. Kovar ring's compressive stress rises substantially as the Y-directional installation error varied from −15 mm to 15 mm compared to other errors. With tracking errors exceeding 8 mrad, bellows' tensile stress and Kovar ring's compressive stress diminish under installation error. Thus, larger tracking errors significantly reduce the threat to the receiver when installation errors exist. [ABSTRACT FROM AUTHOR]

Significant increases in renewable energy are needed in electricity systems in order to reduce greenhouse gas emissions, particularly in the face of increasing electricity demand arising from the electrification of heat and transport. Greater flexibility is required in the electricity system to facilitate this, using proven flexibility providers such as batteries and interconnection or new technologies yet to be proven. This paper investigates how the relationship between battery and interconnection development and carbon price can impact carbon dioxide emissions and renewable energy curtailment. The study simulates twenty-eight scenarios and sensitivities using a unit commitment and economic dispatch model of a 2030 European power system that acknowledges that coal will not be fully eliminated from the 2030 generation mix. The results show that interconnection and battery deployment can alleviate renewable energy curtailment by over 2.4 TWh for the basecase, but a high carbon price is critical to ensuring their deployment plays a complementary role in reducing emissions. The paper also examines the impact of batteries and interconnection on solar and wind energy curtailment. It reveals that battery development nearly doubled the solar energy benefits achieved by interconnection development in some cases, while wind energy benefited more from interconnection development. • A high CO 2 price is critical to IC and batteries achieving emissions reductions. • IC can facilitate production of cheaper higher emitting fuels when CO 2 price is low. • Solar energy benefits more from deployment of batteries due to similar timescales. • Diversity of wind profiles can be leveraged with increased interconnection. • Regardless of CO 2 price IC and batteries alleviate renewable energy curtailment. [ABSTRACT FROM AUTHOR]

Increasing the demand for water and energy resources as well as the clean energy policies and the need for pollution emission reduction has developed the research on the renewable energy resources. This paper reviews the recent advances in multi-generation units for heat, electricity, and desalinated water production. It tries to investigate the new papers in this arena which were not mentioned in the previous reviews. The main parts of this work introduce the co-generation systems for the production of "water and electricity", "heat and water", and "electricity, water, and heat". The results show that among the solar energy receiving devices, Photovoltaic/Thermal panels (PV/Ts) and parabolic trough solar collectors are the most used in co-generation systems. On the other hand, a combination of solar collectors and power cycles makes them a suitable choice for the establishment of a large-scale co-generation plant. Therefore, solar collector-based electricity and water co-generation systems have at least 10 times more output capacity than PV- or PV/T-based systems. On the other hand, most heat and water co-generation systems can achieve an output temperature of 60 °C or more and produce around 10000 kg/year of freshwater based on system size. Examining the co-generation systems of water, electricity and heat also shows that these systems have a high production capacity compared to other co-generation systems. Systems based on heliostat solar tower can produce maximum powers of more than 18 MW and fresh water of 90 kg/s. • Recent advances in solar multi-generation units are reviewed. • PV/Ts and parabolic trough solar collectors are most used collectors in cogeneration systems. • RO and MED have more applications in solar-based co-generation units. • Using waste heat can increase technical and economic performance of system. [ABSTRACT FROM AUTHOR]

It is becoming increasingly important for human societies to use renewable energy. More effective energy storage solutions are crucial to increase the share of renewable energy in the domestic and industrial sectors, which consumes a large amount of thermal energy for heating and cooling purposes. There has been little quantitative analysis of thermal energy storage in solar-based cold production units. An efficient method of designing heat and/or cold storage systems and smart operation planning can help a cooling/heating system to be smaller for the same capacity of supply and thereby reducing the costs of initial investment and costs of operation. This paper attempts to show how the size of a heat and cold storage system affects its thermal performance and how it can lower costs and emissions. For this, a solar-assisted thermally driven cooling supply system with various designs and integrations of their cold storage unit is simulated dynamically through a whole year in Qassim region as the case study. The results show that a system design with double solar heat storage and double cold storage in parallel arrangement results in the best techno-economic-environmental performance. For this case, the levelized cost of cooling will be 383 USD/MWhr, which will be at least 3% lower than the typical hot/cold buffer tank design scenario. [ABSTRACT FROM AUTHOR]

The increase of Renewable Energy (RE) production to fight the climate crisis is posing new technological and financial challenges, due to the availability and variability of RE Sources (RES). These challenges can be addressed by selecting the most suitable mix of RES to optimise power production, to assure grid resilience and to promote local energy use. To facilitate the selection of such combination, this paper presents an original methodology that allows to compare mixing scenarios with different RES, also in presence of batteries and backup system. It simultaneously optimises the energy surplus with respect to the eventual external electrical load and the missing energy with respect to the same electrical load. This method, which can cope with isolated or plugged-to-grid systems, is here applied to a novel case study, an oil&gas platform under decommissioning, located in the Adriatic Sea (Italy). The RE production from wind, wave and solar panels is supposed to support other activities for the platform reuse, such as aquaculture, monitoring and mineral deposition. In this case, solar energy is providing the greatest contribution to the optimal mix in terms of production, while wave energy assures the most relevant contribution in terms of continuity. [ABSTRACT FROM AUTHOR]

Renewable portfolio standard is an effective administrative tool to guide the behavior of electricity producers and impact the renewable energy diffusion. However, currently the renewable energy quota is generally set to be static and the efficiency is limited. In this paper, we proposed a dynamic renewable portfolio standard policy and we aimed to analyze how it will impact the renewable energy diffusion in China. The connections between electricity producers were simulated under both the perfectly competitive market and monopoly market. And a networked evolutionary game approach is applied considering dynamic linking between the electricity producers. The results show that dynamic quota policy is effective in promoting the proportion of wind power generation from 20% to 59.17% and promoting the proportion of solar power generation from 20% to 79.25%. With the sensitivity analysis, we found that renewable energy quota and the on-grid price are the most influential parameters. The proportion will reach 76.47% if quota is 0.7 and 68.1% if on-grid price is 630 Yuan/MWh. And the influence of tradable green certificate prices and generation cost is limited in promoting renewable energy diffusion. This paper offers the Chinese government a potential implementation for the perfection of national renewable energy diffusion. [Display omitted] • Propose a novel dynamic renewable portfolio standard scheme. • Analyze the influences of different kinds of the electricity market. • Investigate parameters affecting the wind power and solar power generation. • Establish dynamic networked evolutionary game models. • Dynamic linking is considered when the connections of players change. [ABSTRACT FROM AUTHOR]

Global warming is one of the most important environmental problems in the world. One might state that the most potential considerable cause of global warming is the increase in greenhouse gas emissions in the atmosphere. The commonly suggested method used to struggle with this potential problem is to consume renewable energy sources instead of fossil fuels. In today's World, where the rate of urbanization is very high, the research on the effect of the energy demand of the residential sector on global warming has become a crucial research topic in the energy and climatic literature. Among different solar sectors, the residential sector is a major energy consumer. Considering the residential, commercial, and industrial solar sectors, the residential solar sector has become a major component of total solar energy. It accounts for approximately 43% of total solar. On the other hand, to the best of my knowledge, there exists no empirical study in the literature considering the influence of residential solar consumption on environmental quality. Thus, determining the effect of the most used energy source, residential solar, energy consumption on the environmental quality has arisen the key research problem of this paper. This research analyzes the effects of residential solar energy usage on CO 2 emissions for the period 1989:1–2020:1 in the USA. It has been observed throughout Morlet wavelet analyses that the use of residential solar energy has a strong effect on mitigating CO 2 emissions in the 1–2 year frequency. Eventually, this paper provides relevant potential energy policies that can enhance the efficiency of residential solar energy consumption. Partial wavelet coherence (RSolar-CO 2 || Coal, Hydro, IP), 1989:1–2020:1. [Display omitted] • Considers the impact of residential solar consumption (RSolar) on CO 2 emissions. • Follows the data for the USA for the monthly period 1989:1–2020:1. • Launches wavelet models in which RSolar, CO 2 , Coal, Hydro, and IP are employed. • Reaches the negative impact of RSolar on CO 2 in the USA for the period 1989:1–2020:1 at 1-2 year-cycle period. • Through potential energy policies, residential solar energy consumption efficiency should be increased. [ABSTRACT FROM AUTHOR]

Renewable energy attracts increasing attention from both industry and academia under the context of carbon neutrality. For wind and solar energy, the strong dependence on natural processes results in the imbalance between energy production and real demands. Energy storage technologies, e.g., Compressed Air Energy Storage (CAES), are promising solutions to increase the renewable energy penetration. However, the CAES system is a multi-component structure with multiple energy forms involved in the process subject to high temperature and high-pressure working conditions. The CAES system is a complex process flowsheet consisting of charging and discharging process. The process should be optimized to achieve the best thermodynamic and economic performance. Under the optimal design conditions, it might lead to severe consequences once a failure occurs, e.g., harm to humans, the environment, and assets. Limited attention and scarce available information have been paid to the CAES system risk management yet. Hence, this paper applies the System-Theoretic Process Analysis (STPA), which is a top-down method based on system theory, to identify the CAES system safety hazards. The results are expected to provide a preliminary guideline for practitioners regarding the safety and reliability of the CAES system. As a result, a more reliable CAES system can contribute to a more flexible energy system with more efficient and economic utilization of fluctuating renewable energy. [ABSTRACT FROM AUTHOR]

The combination of biomass and solar energy in the combined cooling heating and power (CCHP) system is conducive to reducing carbon dioxide emissions of the system. To improve the system's economic performance under the punishment of carbon tax, this paper optimizes the system from system design and operation strategies. A hybrid renewable energy CCHP system with shaft power distribution structure of an internal combustion engine (ICE) is proposed. By optimizing the shaft power distribution of ICE, the direct drive heat pump is realized, and the efficiency of the shaft power of ICE is improved. A double-layer optimization method considering the long and short-term benefits is proposed based on the system, fully improving the system economy in design and operation. The case study shows that the CCHP system reduces the annual cost by 40.37% and the CO 2 emission by 88.93% compared with the separate production system. Compared with the non-shaft power distribution system, the maximum daily operation cost is saved by 557.11CNY. Compared with the hourly optimization method, the proposed optimization method based on total daily benefit reduces the annual cost by 7.73% and CO 2 emission by 35.87%, and the utilization rate of the energy storage device is higher. [ABSTRACT FROM AUTHOR]

In the pursuit of sustainable energy solutions, the integration of renewable energy sources and hydrogen technologies has emerged as a promising avenue. This paper introduces the Integrated Renewable Energy-Driven Hydrogen System as a holistic approach to achieve energy independence and self-sufficiency. Seamlessly integrating renewable energy sources, hydrogen production, storage, and utilization, this system enables diverse applications across various sectors. By harnessing solar and/or wind energy, the Integrated Renewable Energy-Driven Hydrogen System optimizes energy generation, distribution, and storage. Employing a systematic methodology, the paper thoroughly examines the advantages of this integrated system over other alternatives, emphasizing its zero greenhouse gas emissions, versatility, energy resilience, and potential for large-scale hydrogen production. Thus, the proposed system sets our study apart, offering a distinct and efficient alternative compared to conventional approaches. Recent advancements and challenges in hydrogen energy are also discussed, highlighting increasing public awareness and technological progress. Findings reveal a payback period ranging from 2.8 to 6.7 years, depending on the renewable energy configuration, emphasizing the economic attractiveness and potential return on investment. This research significantly contributes to the ongoing discourse on renewable energy integration and underscores the viability of the Integrated Renewable Energy-Driven Hydrogen System as a transformative solution for achieving energy independence. The employed model is innovative and transferable to other contexts. [Display omitted] • Integrating renewable energy and hydrogen for energy independence. • Advantages of Integrated Renewable Energy-Driven Hydrogen System: Zero emissions, resilient energy. • Economic viability: Payback period of 2.8–6.7 years. • Technological progress in hydrogen energy. • A novel and transferable system dynamics model for sustainable solutions is proposed. [ABSTRACT FROM AUTHOR]

In the pursuit of sustainable energy solutions, the integration of renewable energy sources and hydrogen technologies has emerged as a promising avenue. This paper introduces the Integrated Renewable Energy-Driven Hydrogen System as a holistic approach to achieve energy independence and self-sufficiency. Seamlessly integrating renewable energy sources, hydrogen production, storage, and utilization, this system enables diverse applications across various sectors. By harnessing solar and/or wind energy, the Integrated Renewable Energy-Driven Hydrogen System optimizes energy generation, distribution, and storage. Employing a systematic methodology, the paper thoroughly examines the advantages of this integrated system over other alternatives, emphasizing its zero greenhouse gas emissions, versatility, energy resilience, and potential for large-scale hydrogen production. Thus, the proposed system sets our study apart, offering a distinct and efficient alternative compared to conventional approaches. Recent advancements and challenges in hydrogen energy are also discussed, highlighting increasing public awareness and technological progress. Findings reveal a payback period ranging from 2.8 to 6.7 years, depending on the renewable energy configuration, emphasizing the economic attractiveness and potential return on investment. This research significantly contributes to the ongoing discourse on renewable energy integration and underscores the viability of the Integrated Renewable Energy-Driven Hydrogen System as a transformative solution for achieving energy independence. The employed model is innovative and transferable to other contexts. [Display omitted] • Integrating renewable energy and hydrogen for energy independence. • Advantages of Integrated Renewable Energy-Driven Hydrogen System: Zero emissions, resilient energy. • Economic viability: Payback period of 2.8–6.7 years. • Technological progress in hydrogen energy. • A novel and transferable system dynamics model for sustainable solutions is proposed. [ABSTRACT FROM AUTHOR]

In recent years, harvesting solar energy as a renewable and sustainable energy source has been studied extensively across engineering fields. Having reviewed more than 50 large-scale projects of Hydronic Asphalt Pavement (HAP), this paper offers a series of findings: the range of construction cost of asphalt collector varies between 25 and 151 €/m2 and 1.760–3.000 €/m2 for the heat exchanger and the total cost. The energy harvest capacity of asphalt solar collector systems (0,6–0,8 GJ/m2/year) and the required amount of heat for snow melting projects (100–900 W/m2) vary significantly in different projects. Using grid supports for easier pipe placement and protection of pipes against heavy loads during and after construction is recommended. Pavement solar collector systems reduced carbon dioxide emissions by 8–100% in different projects by changing their source of energy from fossil fuels to renewable and sustainable sources. Moreover, in order to further evaluate the sustainability of the HAP systems, a detailed life cycle assessment is required, including all available data related to the energy performance, pavement service life, material end-of-life recycling, etc. Finally, the paper identifies the knowledge gaps requiring further research especially in the area of energy output of the HAP systems, pavement service life and life cycle assessment. • A comprehensive review of large-scale hydronic asphalt pavement projects is provided. • Potential challenges in the large-scale hydronic asphalt pavement are investigated. • Technical specifications, operational aspects and performance are explored. • Construction cost and structural response of systems are analyzed. • The projects' performance is evaluated based on energy output and sustainability. [ABSTRACT FROM AUTHOR]

Distributed energy systems are becoming increasingly popular worldwide. The 100% renewable energy system can be an important energy supply alternative to reduce the carbon emissions and address energy shortage, especially for remote areas. However, the performance of 100% renewable energy system (RES) at community level needs further detailed analysis, which is affected by the climates, availability of renewable energy and local energy markets. This paper proposes a design optimization framework of 100% renewable energy systems for low-density communities and investigates the system performance. To investigate the integration and performance of 100% RES, thirty typical cities located in different regions of China were chosen considering different climates, geographical features, and renewable energy distributions. By taking the economic performance as the optimization objective, the optimal design for the 100% RES is obtained, and the energy and economic performance is analyzed. Results show that, under the current energy market conditions, the 100% RES is feasible for low-density communities in most regions of China. The payback periods of the systems in most cities are less than six years. When the cost of PV is reduced by half considering future technological developments, the payback period of a 100% RES can be reduced by 30%–60%. This paper would provide design suggestions and application recommendations in regard to promoting 100% RES in China. • Application of 100% renewable energy system at community level is studied. • 30 zones are selected considering climates, renewable energy sources and markets. • Solar energy and biomass can contribute to over 90% of the total energy supply. • Investment of 100% RES can be paid back in 6 years for most regions. • Payback periods can be reduced by 30%–60% when PV technology is further developed. [ABSTRACT FROM AUTHOR]

In order to mitigate the influence of global warming and greenhouse gasses emission, different proceedings are suggested such as utilizing renewable energies and demand response programs. This paper investigates the expansion of renewable resources and electrical energy storage units in distribution systems towards reducing investment costs and environmental pollution. Since the development of components is not possible in a single-stage due to the limitation of staff and funds, a multi-stage programming is applied to consider various restrictions. According to the penetration of crypto-currency miners in recent years, their impact is evaluated on the problem as the high-rate energy consumers. Moreover, the demand side management strategy and risk-averse scenario-based approach are implemented to analyze the role of responsive loads and model the renewable resources uncertainty, respectively. The results approve that simultaneous expansion of wind turbines, photovoltaics and electrical storage systems decreases the total pollution and cost by 100% and 99.98% after the third year, respectively. The simulations also validate that crypto-currency miners reduce the total revenue by 4.16%, whereas the responsive loads increase it by 9.89%. As well, the fluctuations of wind and solar power decrease the total revenue by 13.27%, in return, the robustness notably improves. [ABSTRACT FROM AUTHOR]

In 2020 the European Commission approved the GND (Green New Deal), a strategic plan aimed at the decarbonization of the EU by 2050. In this scenario, the diffusion of alternative renewable energy sources (RESs) play a key role, particularly electric energy production from wind and photovoltaic power plants. Regardless, the nonprogrammable nature of these power sources led recent studies to focus the interest on the power-to-gas solution (PtG), consisting of the electrolytic transformation of excesses of unused electric energy into hydrogen. The complexity of this technology requires the development of strategic optimization models aimed at finding the best locations for new PtG plants in specific territorial scenarios. This paper presents the development of a GIS-based optimization model that combines an operational research approach with territorial services based on geographic information system (GIS) data. The study is located in Sicily (Italy), considering the large renewable energy penetration in the larger Mediterranean island. The developed model allows us to find the best location for new PtG installations in the considered area by combining GIS automated processing with cost function resolution. The results of this work could be useful in the years to come in light of the rapid spread of hydrogen energy production in Italy. [Display omitted] [ABSTRACT FROM AUTHOR]

This research examines the effect of environmental policy stringency on green innovation in renewable energy technology and whether the green innovation response differs with varying degrees of environmental policy. Based on panel data of 33 countries over the period 1990–2015, we show that a stringent environmental policy does encourage green innovation in renewable energy technology, and this impact is more pronounced in OECD countries and high-income countries. More specifically, a stringent non-market-based environmental policy induces more patents in renewable energy generation. The findings also show that a stringent environmental policy yields green innovation for geothermal energy, hydro energy, and marine energy, but not for wind energy and solar energy. Heterogeneity analysis suggests that innovation capacity and environmental pressure enhance the impact of environmental policy stringency on green innovation in the renewable energy field. Finally, the paper presents that clean energy investment plays the role of a mechanism through which environmental policy stringency spurs green innovation in the renewable energy field, offering insights into the influence of environmental policy stringency on green innovation. [ABSTRACT FROM AUTHOR]

The intermittent nature of renewable energy resources is a major obstacle in utilizing such resources for power generation despite their abundance. In this paper, a dynamic analysis of an integrated system based on photovoltaic (PV) panels and wind turbines coupled with pumped hydro energy storage is presented. When the power generation exceeds the power demand, surplus electricity is used to pump the water to the upper reservoir. The natural inflow of the river obviates the necessity for oversized reservoirs and saves costs. A recently introduced multi-objective equilibrium optimizer algorithm is developed to find the optimal size of the integrated hybrid energy system. The objectives are to minimize the levelized cost of electricity and maximize the reliability of the proposed system. The results show that the correlation between solar and wind power generation in the selected location is mildly strong with a value of 0.3. The total energy generation from hydro, solar, and wind resources are 77,508.7 kWh, 103,323 kWh, and 47,375.4 kWh, respectively. Comparing the results with other algorithms indicates that the equilibrium optimizer has a better performance in finding the optimal design. [ABSTRACT FROM AUTHOR]

With the increasing proportion of variable renewable energy characterized by fluctuation and the promotion of the "Clean Heating" policy, the problem of seasonal energy imbalance of the system has become increasingly challenging. There is a lack of effective means to mitigate this challenge under the background of gradual compression of the construction space for traditional thermal units. Concentrated solar power (CSP) is a promising technology to replace thermal units by integrating emergency boilers to cope with extreme weather, and can meet long-time energy balance as a seasonal peak regulation source. In this paper, we propose a long-term high-resolution expansion planning model of energy systems integrating CSP to address seasonal energy imbalances. The model takes into account both investment and operation considerations in full hourly resolution for the whole year based on a fast cluster optimization method. With the projection to 2050, we take the energy system in Xinjiang province which is a typical area of the "Clean Heating" project with rich irradiance as a case study. It shows that the optimal deployment of CSP and electric boiler (EB) can result in a 8.73 % reduction in costs, a 19.72 % decrease in the peak-valley difference of net load, and a substantial 58.24 % reduction in renewable curtailment at 65 % renewable penetration compared to the base scenario. [ABSTRACT FROM AUTHOR]

The global water scarcity crisis has led to increased demand for reverse osmosis (RO) desalination technology. In response to the rising global temperatures, there is a growing focus on renewable energy sources such as solar photovoltaic (PV) and wind energy to power small-scale RO plants. This paper presents a comprehensive techno-economic analysis of stand-alone photovoltaic reverse osmosis (PV-RO) systems in Pakistan. It focuses on the design and optimization of PV-RO systems for Karachi and Lahore, evaluating the systems with and without energy recovery devices. A parametric study was conducted to optimize system performance, considering various configurations. The analysis includes a comparison of costs when operating with PV, diesel, and grid power. It was found that for Karachi, a four-stage PV-RO system without an energy recovery device provides water at $1.359 per cubic meter, while in Lahore, a three-stage system with an energy recovery device achieves $1.336 per cubic meter. These systems offer significant annual savings compared to diesel-powered systems, with Karachi and Lahore saving up to $10,138 and $17,664 respectively over ten years. The findings of this study show that PV-RO systems, especially those with multiple stages and energy recovery devices, offer a cost-effective and sustainable solution for water desalination in these regions. [ABSTRACT FROM AUTHOR]

This paper proposes the first application of a split-range control technique on a concentrating solar collector to improve an absorption plant production. Solar absorption plants have solar power availability in phase with cooling demand under design conditions. Thus, it is a powerful cooling technology in the context of renewable energy and energy efficiency. These plants need control systems to cope with solar irradiance intermittency, reject irradiation disturbances, manage fossil fuels backup systems and dump closed-loop thermal-hydraulic oscillations. In this work, control techniques are proposed and simulated in an absorption plant in Spain. The plant consists of a concentrating Fresnel solar collector connected to an absorption chiller. The objectives are to operate with 100% renewable solar energy and avoid safety defocus events while reducing temperature oscillations and control actuators effort. Firstly, the current available plant controllers are defined, then two modifications are proposed. The first modification is a split-range controller capable of manipulating both flow and defocus of the Fresnel collector, the second modification is a PI controller to substitute the original chiller on-off controller. The results compare, through validated models, the different control systems and indicate that using both proposed controllers reduces 94% of the sum of actuators effort and 43% of the integral of absolute set-point tracking error compared to the plant's factory pre-set controllers. The suggested controllers increase 66% of energy production and 63% of exergy production. Besides, the split-range technique can be extended to any concentrating solar collector control. [Display omitted] [ABSTRACT FROM AUTHOR]

Poverty alleviation is an important work of the Chinese government in recent years. According to the international poverty standards of the world bank, China's poverty reduction population accounts for more than 70% of the world. Photovoltaic poverty alleviation is a significant way for regions rich in solar energy resources to transform the advantages of renewable energy resources into the driving force of social and economic development. It is also an effective means for China to implement power poverty alleviation. While promoting emission reduction in these regions, it accelerates economic development and implements targeted poverty alleviation. This paper analyzes the comprehensive benefits of typical market entities of photovoltaic poverty alleviation projects, and establishes the environment, economic and social benefit evaluation models for poor households, the state and government, photovoltaic enterprises and grid corporation. In the model, we creatively put forward an index system to characterize the poverty alleviation effect, and consider the additional industrial benefits brought by photovoltaic poverty alleviation projects. Finally, a typical photovoltaic poverty alleviation project in Haiyuan County, Northwest China is selected to verify the feasibility of this model. [ABSTRACT FROM AUTHOR]

A power system with 80% renewable energy sources (RES) requires significant provision of flexibility to balance the deviations of fluctuating solar and wind power. This paper focuses on how a smart mix of renewable generation technologies can reduce the demand for flexibility and therefore the overall system costs. To measure the demand for flexibility in systems with high RES generation, the term flexibility is defined and described using predictable indicators such as the difference between the highest and the lowest residual demand or the number of hours with negative residual load during a year. This definition is required to determine the optimal mix of RES installations. Optimization is performed for Germany based on the grid development plan of the transmission system operators. In contrast to most studies of the future energy system that foresee a further expansion of onshore wind, this paper shows that higher shares of offshore wind and, to some extent, photovoltaic are better suited to reducing the demand for flexibility and thus the cost of integrating fluctuating RES into the system. • Extended definition of flexibility demand for power systems based on renewables. • Offshore wind and photovoltaic requires less flexibility than onshore wind. • Uncertainty about the future renewable mix increases system integration costs. • Challenge: trade-off between levelized cost of generation and system integration. [ABSTRACT FROM AUTHOR]

The increasing generation of renewable energy and its concurrent technological innovation are driving the transformations of the energy sector, but little effort has been made at the regional level to specify the heterogeneous impacts of different types of renewable energy development on multi-dimensional energy security. Therefore, this paper establishes a four-dimensional energy security assessment system based on the current energy market situation and economic context of China. Renewable energy generation and technological innovation were simultaneously used as the core proxies for renewable energy development. Then, the panel quantile regression method was used to analyze the heterogeneity of the impact of solar, hydro, and wind energy on energy security, covering 30 provinces in China from 2006 to 2019. The empirical results show that renewable energy power generation generally promotes energy security, but it cannot be effectively applicable to all levels of energy security. Renewable energy technology innovation has surprisingly hindered energy security. These results can serve as a policy and practical guide, suggesting that provincial governments in China should implement energy security and renewable energy policies in line with local characteristics. • The redefined provincial energy security presents obvious spatial heterogeneity. • Panel quantile regression was applied to balanced provincial panel data. • Hydropower contributes only to medium and low levels of energy security. • Wind and solar power contribute differently to all levels of energy security. • Renewable energy technological innovation impedes energy security. [ABSTRACT FROM AUTHOR]

This paper aims to provide a scientific approach that indicates the need to focus on renewable energy potential to meet energy needs in Turkey. Turkey began to take advantage of renewable energy technologies a few years ago. Accordingly, the issue of determining the best renewable resources for the country has been brought to the agenda in recent years. The issue was considered to be a limited multi-objective optimization problem allowing us to achieve a reliable result. However, the parameter of each resource was considered as a range value, rather than traditionally expressed as an exact value, and a multi-objective decision problem was developed with an interval coefficient. This method allows us to obtain more accurate and reliable results without the need to resort to normalization methods used to eliminate unit differences. According to the results of this study, the most convenient alternatives for Turkey are hydro, wind, and solar power. The findings also support decision policies aimed at reaching targets for the electricity sector in 2023, as put forth by the Ministry of Energy and Natural Resources (MENR). • Multi-dimensional analysis of optimum renewable energy resources for a sustainable economy. • Selection of renewable energy sources under uncertainty. • More sensitive selection of resources by representing the instability in expert opinions with interval numbers. • The most optimum renewable energy resources for Turkey: "geothermal, solar, and wind.". [ABSTRACT FROM AUTHOR]

The curtailment of renewable energy worsens with increasing penetration in power systems, so it is necessary to explore the upper limit value of the penetration of renewable energy (PRE). This paper uses artificial neural networks (ANN) to study the historical data of California independent system operator (CAISO), analyze the fluctuation balance strategy of wind and solar power, and predict the upper limit value of the PRE, which will peak at 40.5% in 2025. In addition, this paper also simulates the inclusion of energy storage unit (ESU) with an installed capacity of 3 GWh in the grid to reduce curtailments, and analyzes the grid operating conditions and the upper limit value of the PRE, showing that the storage units with an installed capacity of only 3% of the average daily power output of solar energy recover 58% of the annual curtailments (2021), and the maximum PRE is 41.2%. [ABSTRACT FROM AUTHOR]

With the ongoing increase of variable renewable energy sources (VRES), such as wind or solar power, weather dependent production profiles induce uncertainty on the supply side and change operations at large in wholesale power markets. In this paper, we study how an increasing market share of VRES affects spot power price dynamics and the forward price premium. Using data from simulated power markets, we analyse the forward premium in three identical power markets with a varying market share of VRES supplied to the system. We demonstrate that markets with a high share of supply from VRES yield a significantly lower forward premium than markets with a low market share of wind or solar supply. Our results further confirm that, regardless of the market share of supply from VRES, forward power prices contain information about future spot power prices. These insights generate important implications for producers, retailers and other market participants exposed to wholesale price risk. • Variable renewable energy sources impact price dynamics in forward and spot power markets. • Supply from variable renewable energy sources decreases power price forward premiums. • Forward power prices contain information about future spot power prices. • The study suggests implications for market participants exposed to power price risk. [ABSTRACT FROM AUTHOR]

Worldwide, the emerging trend of hybrid renewable energy sources integration in modern power systems is increasing due to privileged prices and clean electricity supply. However, the optimal planning of rural hybrid systems is a challenging and complex task, especially when different alternatives and sustainability aspects are considered. This paper develops an integrated decision-making approach for the optimal planning of a 100% renewable energy supply system comprising solar, wind, hydro, and biomass sources in a rural area located in Pakistan. An hourly-based design optimization analysis of twelve on/off-grid electrification alternatives is performed. The optimization model simultaneously addresses five sustainability criteria related to economy, reliability, ecology, society, and topography aspects. Furthermore, a novel hybrid decision-making model has developed to identify the unique best configuration with on-grid and off-grid options. The proposed model combines fuzzy analytic hierarchy process, multi-objective optimization based on ratio analysis technique for order of preference by similarity to an ideal solution, and evaluation based on distance from average solution methods. The results reveal that the solar-hydro-biomass battery with a life cycle cost of 10.9 M$ is the top-ranking off-grid system. When the hybrid system is connected to the grid, the solar-hydro-battery has found the most appropriate design with a life cycle cost of 12.96 M$. Both scenarios have a negligible capacity shortage of 0.09%. Ecologically, the optimal off-grid system produces only 408.37 kg/yr of CO 2 due to the significant energy share of solar and hydro sources (99.3%). The optimal on-grid system produced the minimum CO 2 with 29,177.89 kg/yr compared to other alternatives. Also, employing the optimal on/off-grid designs require land area and jobs of 96.6 m2, 14 jobs, and 118 m2, 15 jobs, respectively. Overall, the developed approach with the presented case study offers a valuable benchmark and guidelines for investors and stakeholders to create realistic investment plans for the energy industry looking to push efficient inducements to encourage the high dissemination of renewables. [Display omitted] • 100% renewable energy system is established for on/off grid rural electrification. • Twelve distinctive solar/wind/hydro/biomass-based hybrid energy alternatives are optimized. • An integrated fuzzy-AHP/TOPSIS/EDAS/MOORA decision-making model is proposed. • Cost, reliability, emission, social, and topographical criteria are simultaneously considered. • Results prove the long-term sustainability of 100% renewable in rural Pakistan. [ABSTRACT FROM AUTHOR]

The State of Illinois is examining prospects to increase the development of in-state renewable energy resources on public lands. In response, this research develops a scalable decision-support tool for identifying suitable areas for solar energy generation in the state. This paper provides guidance for state agency-driven solar development by evaluating the suitability of potential generation areas in terms of environmental impact, socioeconomic costs, and energy productivity, and providing a forum for critical decision-making. More specifically, geospatial technologies are combined with a suitability analysis to reveal the potential for solar energy generation on public lands. This study demonstrates the usefulness of the resulting information for supporting both regional and local decision-making as a Planning Support System (PSS). Our analysis suggests that the large-scale analysis using fine resolution data is useful for comparison and site-specific decision making - with site verification protocols in terms of physical implementation. We find that planning decisions for solar development should use a fine-grained suitability approach at a large scale and a feasibility analysis at a specific scale. We present our findings in statewide application along with a scalable PSS tool to optimize and support solar decision-making process and democratize the information for engaging a broader audience. [Display omitted] [ABSTRACT FROM AUTHOR]

Hybrid solar and geothermal utilisation is a promising option for effective exploitation of renewable energy sources. Concentrated solar power (CSP) systems with geothermal preheating are acknowledged as an attractive solution, with supercritical CO 2 (SCO 2) cycle systems adopted for power generation thanks to the favourable properties offered by CO 2 as a working fluid. In order to further improve the overall performance of such systems, organic Rankine cycle (ORC) systems can be added as bottoming cycles to recover the heat rejected from the topping SCO 2 cycle system and also to utilise surplus geothermal heat available after the brine is used for preheating in the SCO 2 system. This paper proposes four configurations of combined SCO 2 -ORC system for hybrid solar and geothermal power generation and performs detailed thermodynamic and economic assessments based on actual conditions in Seville, Spain. The results reveal that combined systems in which the geothermal-brine stream is split into two parallel flows and utilised separately by the topping SCO 2 cycle and bottoming ORC systems are preferable. A split geothermal-stream combined system with the ORC working fluid first utilising geothermal heat followed in series by heat from the topping SCO 2 cycle system delivers a net power output of 2940 kW, which is the maximum among all the proposed configurations and is 45% higher than that of a standalone SCO 2 plant. A similar combined system with a reversed ORC flow direction such that the organic fluid is preheated first by utilising heat from the SCO 2 cycle system and then by geothermal heat has a specific cost corresponding to the maximum net power output of 2880 $/kW, which is the lowest among all the configurations and is 22% lower than that of the standalone SCO 2 plant. Annual performance evaluation shows that the combined systems can achieve significant improvements, ranging from 22% to 45%, over the total electricity generation of the standalone SCO 2 plant, which demonstrates the significant potential of deploying such novel and promising combined systems for hybrid solar and geothermal power generation. [ABSTRACT FROM AUTHOR]

The Canary Islands are still largely dependent on expensive imported fossil fuels, are stressed by the increasing touristic impact and are extremely vulnerable to climate change due to water scarcity. Water desalinisation is an energy-demanding process and is essential to the sustainable development of these islands. The aim of this study is to explore the potential advantages of a hybrid installation, exploiting two different renewable energy sources, specifically waves and solar, to supply a large desalination plant in Tenerife. The paper ultimately provides a generally applicable procedure for the design of hybrid installations, including three steps: the assessment of available renewable energy sources, the optimal combination of these sources and finally the economic assessment. The wave and solar resources are assessed first, then the hybrid installation is conceptually designed, proposing a criterion for the optimal mixing of the renewable energy sources that can be applied to other resources and other sites. The basic idea is to maximise the exploitation of the renewable power, minimizing the need of the fossil-based back-up system. The costs of the hybrid installation are finally assessed considering the sensitivity to government incentives, showing that the project parity point is reached within the lifetime of typical desalination plants (i.e. 40 years) and can be significantly more attractive in case of Feed-In-Tariffs available in other European countries. [ABSTRACT FROM AUTHOR]

Abstract The main goal in this paper is to supply a national load by multiple renewable power connections to utility grid at different geographic locations. The national load demand of the country of Jordan is supplied in this case study by finding the optimal configurations and locations (near cities). Cities of higher potential for wind and/or photovoltaic (PV) energy location are selected for connecting to renewable power. The annual system cost of energy (ASCE) for this optimized renewable energy system is shown to be 32.57% less than the conventional grid energy price. Further, the Carbon Dioxide (CO 2) emissions are reduced by 80.13%. These are excellent indications for the feasibility and environmental benefits of retrofitting conventional grid with renewable power in developing countries. Multi-figure of merits (MFOM) based on a Nondominated Sorting Genetic Algorithms (NSGA) optimization cases are investigated which include annual emission indicator (AEI), ASCE, levelized cost of energy (LCOE) and renewable penetration (RP). Results are either two dimensions (2D) or three dimensions (3D) Pareto frontier, where various competitive non-dominant solutions exist. A sweet spot selection (triple-S) procedure is proposed to help select the best point in the two (figure of merits) FOMs Pareto frontier to have both environmental and feasible solutions. Highlights • The contributions of this paper are multi-point connection to a national grid, holistic definition and modeling of the engineering and financial problems, optimal design tool solutions to the multi-point connection problem definition and model, suggesting this as a case study of the concept of "local solutions for a global problem." Such a holistic approach is recommended especially in the developing countries. • The importance of moving toward sustainable energy stems from global climate change and the need to provide access to affordable energy to all of humanity. The ultimate goal is to satisfy a country's national load demand by establishing multiple utility grid connections to various geographic locations of high wind or solar energy resources. This is done by building a new optimization design tool which investigates economic feasibility and environmental impacts. Then, Single figure of merit and multi-figure of merits optimizations have been investigated. • A mathematical modeling is developed for each component, and the optimal configuration is determined for each city. The annual system cost of energy (ASCE) is optimized to be 32.57% less than grid energy price, and the CO 2 emissions (AEI) are reduced by 80.13%. These are excellent indications for the economic feasibility and the environmental benefits of the designed system. The levelized cost of energy (LCOE), total net present cost, renewable penetration (RP) and AEI are 0.058212 $/kWh, $8.713857 billion, 59.49817% and 4.576 Megatonne/year respectively. • A new equation to calculate the salvage cost has been developed in this paper. Moreover, a new procedure in a multi-optimization problem was developed in this paper, which is the Sweet Spot Selection (triple-S) procedure. It is developed to help select the sweet point in the two FOMs Pareto frontier to have both environmental and economic feasible solutions. • Multi-figure of merits (MFOM) optimization cases based on a non-sorting genetic algorithm are investigated such as: AEI vs. ASCE, AEI vs. LCOE, AEI vs. RP and (RP, LCOE, AEI). The MFOM optimization results are either 2D or 3D Pareto frontier, where exists various competitive non-dominant solutions. The sweet spot selection (triple-S) procedure is proposed to help select the sweet spot in the two figure of merits Pareto frontier in order to have both environmental and feasible solutions. [ABSTRACT FROM AUTHOR]

Using conventional fossil fuels causes both energy crisis and environmental pollution. Renewable energy with the merits of almost unlimited availability and environmental-friendliness provides a perfect solution to the problem. Solar energy is widely recognized as one of the most important renewable energy resources due to its even distribution, safety and serving as sources for others. In past decades, global solar thermal capacity increases rapidly and now it has been widely used worldwide to provide heating and cooling. To understand the current progress of relevant technologies and the future development, this paper briefly summarizes the current situation of solar heating and cooling, and then some new achievements in related areas and potential future market penetration are discussed. It is found that solar hot water heating system's development is in fast lane in recent years with evacuated tube solar collector dominating the mass market. How to integrate solar collecting system with different types of buildings is the main research and development direction for solar building heating system. Large-scale district water heating system and solar PVT system as the most promising solutions attract extensive attentions. For solar cooling, efforts have been made to improve the efficiency of conventional solar thermal cooling methods in terms of adsorption and absorption technology. In addition to technical development, economic analysis of solar heating and cooling system is also discussed. Return of investment period is widely adopted to evaluate the economic performance. Results reveal that low initial cost and advantageous allowance are the most efficient ways to make solar heating and cooling system economically attractive. This paper is presented and recommended by 5th International Conference on Nuclear and Renewable Energy Resources. [ABSTRACT FROM AUTHOR]

China, India, and the USA are the world's biggest energy consumers and CO 2 emitters. Being the leading contributors to climate change, these economies are also at the core of environmental solutions. This paper investigates the causal relationship among solar and wind energy production, coal consumption, economic growth, and CO 2 emissions for these three countries. To do so, we use an advanced methodology in Machine Learning to verify the predictive causal linkages among variables. The Causal Direction from Dependency (D2C) algorithm set CO 2 emissions as the target variable. The obtained results were disaggregated and estimated in a supervised prediction model. The findings, confirmed by three different Machine Learning procedures, showed an interesting output. While a reduction in overall carbon emissions is predicted in China and the US (resulting from the intensive use of renewable sources of energy), India displays critical predictions of a rise in CO 2 emissions. This indicates that curbing CO 2 emissions cannot be achieved without conducting a comprehensive shift from fossil to renewable resources, although China and the U.S. present a more promising path to sustainability than India. Being an emerging renewable energy leader, India should further enhance the use of low-carbon sources in its power supply and limit its dependence on coal. • Renewable energies, coal consumption, economic growth, and CO 2 we examine. • We investigate the causal predicted relationship on China, India, and the USA. • An advanced methodology in Machine Learning is used. • India has a prediction of an increase in emissions of CO 2. • China and the U.S. present a more promising path to sustainability than India. [ABSTRACT FROM AUTHOR]

Under the worldwide carbon neutralization targets, concentrating solar power (CSP) is arousing great attention. With the thermal energy storage (TES), CSP is friendly to the power system operation by supplying controllable renewable energy. The capacities of its solar field and TES are essential parameters for maximizing the profit of a CSP plant. This paper formulates an explicit expression of the CSP plant's profit instead of using a simulation-based method. Then, an unconstrained optimization model is proposed to calculate its optimal configuration directly. This model provides insights into the optimal configuration of CSP with different penetrations of wind power in the case study. The results show that to obtain a better profit for the CSP plant, large solar multiple (more than 3.0) and TES (more than 13 h) are preferred to collaborate with high penetration of wind and photovoltaic plants. The effectiveness of the proposed method is verified compared to the enumeration searching method. The economy and feasibility of installing an electric heater (EH) in CSP are also demonstrated. Generally, the optimal investment in EH is linearly correlated to the penetration of variable energy resources. [Display omitted] • A flexible operation model of CSP with EH is proposed. • An explicit model of CSP's profit based on the solar radiation curve and prices is constructed. • The configuration of the CSP plant is optimized through the first-order optimality conditions on the profit function. • The optimal configuration of CSP with high renewable energy is provided in the case study. [ABSTRACT FROM AUTHOR]

Seasonal pumped storage (SPS) is a sustainable and effective energy storage solution that can mitigate the seasonal fluctuations of renewable energy sources and provide flexibility to power systems. Despite its huge potentials, the operational mechanism of SPS, particularly for the multi-energy complementary operation, remains poorly understood. In this paper, we propose an optimal scheduling model of a regional power system with SPS and evaluate its potential contribution to energy efficiency, power system stability, and environmental impact. A case study in Qinghai, China, demonstrated that SPS effectively managed seasonal fluctuations of renewable energy sources, improved hydropower generation during the dry season, and stored excess power from renewable energy sources and the main power grid. Furthermore, our analysis revealed that SPS significantly improved energy efficiency compared to traditional pumped storage by increasing system energy efficiency by 11.21%, reducing wind and solar power by 72.97%, and lowering carbon emissions by 94.41%. Overall, SPS has immense potential in providing power system flexibility and enhancing the decarbonization of power systems. [Display omitted] [ABSTRACT FROM AUTHOR]

To mitigate the effects of climate change, energy systems are becoming increasingly reliant on renewable energy sources. Since these energy sources are typically dependent on the prevailing weather, renewable energy systems are susceptible to shortages during certain weather conditions. As renewable sources become larger contributors to the energy mix, the risks associated with these shortages, referred to as energy droughts, increase. Techniques are therefore required that can help policymakers to understand and mitigate the impacts associated with energy droughts. In this paper, two standardised indices are introduced to monitor droughts in renewable energy systems. The indices incorporate energy demand and renewable energy production, and constitute analogues to the standardised precipitation index (SPI) and standardised precipitation evapotranspiration index (SPEI), two indices regularly employed operationally to monitor meteorological droughts. The indices are straightforward to construct, can be defined on any timescale, and facilitate comparisons between regions with different climates and installed capacities. We demonstrate how the standardised energy indices proposed herein can be used to define renewable energy droughts, and illustrate the practical utility of these indices in an application to reconstructed time series of electricity demand and wind and solar power generation across Europe. [ABSTRACT FROM AUTHOR]

With the large-scale integration of wind and solar power in China, the consumption of these intermittent renewable energies is severely restricted by the capacity of the transmission channel, which leads to massive renewable energy curtailment. Therefore, it would be beneficial to use limited transmission channels to absorb as much renewable energy as possible. In this paper, we propose a chance constraint-based multistage nested hydro-wind-solar coordinated optimal scheduling model to aid peak shaving while ensuring maximum power generation. First, multistage partitioned section chance constraints are introduced to mitigate the power congestion of the transmission network. Then, based on the principle of using hydropower to complement the uncertainty of wind and solar power, the compensation chance constraints are considered. To quantify the uncertainty of wind and solar power, their prediction errors are analyzed using the Gaussian mixture model. Finally, the model is recast and linearized into a mixed integer linear programming model. A case study of a hydro-wind-solar base in Southwest China demonstrates that the proposed model can effectively leverage the regulation ability of hydropower to coordinate multiple power sources with the restrictions of multistage transmission sections, effectively alleviating the congestion of transmission channels and reducing the curtailment of renewable energy. [ABSTRACT FROM AUTHOR]

This paper presents geographic maps of the profitability of PV and CPV solar projects over 1,960,000 km 2 . Such maps supplement the irradiance maps used in solar project planning and are relevant to government policy makers to assess the impact of incentives on profitability. Also, they are useful to solar project developers to identify geographical areas in which a required rate of financial return can be expected. Eight such maps of central Canada are presented in this paper and show the impact on profitability of different levels of government incentives, the difference in profitability between PV and CPV and the impact on profitability of delaying a project start date from 2016 to 2020. Government incentives of 10%–30% of the capital cost improve the internal rate of return (IRR) by between 0.7 and 4.67. For PV, the orientation of the modules is optimized to achieve maximum IRR resulting in an IRR increase of between 1.3% and 8.2%. Since CPV is a more recent technology than PV, its capital costs are projected to decline faster and we quantify the impact on IRR by showing that CPV has a higher IRR than PV of between 0.55 in 2016 and 3.6 in 2020. [ABSTRACT FROM AUTHOR]

The paper addresses the assessment of the Stirling engine performance by comparing biomass and solar energy as external renewable energy sources. A program-code was developed in the MatLab® to solve the thermal model of an alpha-Stirling engine, accounting for the limitations in the heat transfer processes in the regenerator and the losses due to pumping effects. The solar energy source was modelled as a concentric solar dish collector, considering a receiver located at the focal point and designed to absorb the maximum possible of the solar radiation. Regarding the biomass system, the temperature of the flue gases leaving the bed is computed through an energy balance, considering the fuel energy introduced into the bed, the energy that is provided by the bed and the incident radiation in the bed. The simulation results show that the biomass-fuelled Stirling engine provided 87.5% more power output than the solar energy source, with an efficiency of 46.67%. Also, the average receiver temperature from the solar source is about 775 K, whereas, in the boiler bed, the temperature reaches the value of 1288 K. In the solar-dish modelling, the reflected radiation that passes into the cavity receiver depends on the aperture ratio and rim angle. It was proved that a rim angle of at least 45° is required to ensure lower focal distances. Otherwise, the Stirling receiver needs to be far from the surface of the dish, resulting in higher thermal losses and lower temperature inside the receiver cavity. In biomass-fuelled system, it was shown that the temperature of the flue gases increases with the increasing the radiation flux, and decreases for higher split percentages between the primary and secondary air. The study also revealed the need to investigate the combustion stability regarding the particle emission in the flue gas, which can reduce the temperature close to the hot cylinder of the Stirling engine. The LCoE for the solar-power system is of about 1658 €/kWh, which is 52% higher when compared with the biomass-fuelled system (0.109 €/kWh). In conclusion, biomass-fuelled Stirling engines are able to provide a higher power output with higher thermal efficiency, avoiding the problems usually related to solar energy intermittency. Image 1067 • The solar energy source was modelled as a concentric solar dish collector. • A bed model was developed to predict the flue gas temperature. • The biomass-fuelled Stirling engine provided 87.5% more power output than the solar. • The solar dish Stirling produces 2.3 kW of power with an efficiency of 31.3%. • The biomass-fuelled system produces 4.3 kW of power with an efficiency of 46.7%. [ABSTRACT FROM AUTHOR]

Food spoilage represents an urgent issue in tropical developing countries because of the lack of correctly refrigerated post-harvest storage, transportation and distribution facilities. This paper searches for the best choice of configuration and design parameters of food refrigeration systems integrated with renewable conversion units in tropical areas using a multicriteria approach (energetic, exergetic and economic). Fourty-four technically feasible integrated configurations are identified for three preservation temperatures of the food (8, 2 and −20 °C). Each configuration is simulated from the energetic, exergetic and economic point of view during one year of operation using detailed design and off-design models. A thermal storage or the connection with the electric grid is considered in the integrated configurations fuelled by solar energy to guarantee a continuous operation. Results show that the PV-powered flash-intercooled compression system is the most efficient integrated configuration for each food storage temperature (annual average COP in the range 2.3–5.7) but it represents the most economically viable option only for the highest food preservation temperature. At lower temperatures, the single-effect absorption cycle coupled with a bagasse-fired boiler shows lower costs because of the very low price of bagasse in tropical countries. On the other hand, all options including the half-effect absorption cycle result to be the less promising in terms of both COP and costs. • Flesh-intercooled systems show the highest COP (2.2–4.5) for T food = 8,2,-20 °C. • Best annual COPs (0.9–2.1) are obtained by compression systems + PV-panels. • Best average annual η e x are of the order of 10% (compression) and 5% (absorption). • Compression systems show the lowest total annual costs (575 to 935 € / k W c o o l i n g ). • Selling the electricity from absorption + biogas-ICE options leads to economic gains. [ABSTRACT FROM AUTHOR]

This paper investigates the local complementarity of three types of renewable sources (solar, wind and tidal). One of the main drawbacks of non-conventional renewable energy sources is their intermittent nature. Wind energy depends on the wind speed, which varies throughout the day. The generation of photovoltaic solar energy is strongly affected by clouds, that cause an abrupt drop of power to less than 50% of its rated capacity. In contrast, tidal energy is characterized by a high degree of predictability. This article raises important features of local complementarity of these renewable sources. These properties can be exploited to improve the firm power of isolated microgrids, leading to a variety of beneficial operational consequences. The contributions and conclusions presented here are supported by case studies and real data measured in the coastal region of northern Brazil. [ABSTRACT FROM AUTHOR]

In recent years, the sun has been used as one of the main sources of renewable energy and supplying energy through solar cells has been quickly increased. This paper develops a two-echelon multi-period multi-product solar cell supply chain (SCSC) with three scenarios including (1) The presence of domestic supplier in a monopoly market, (2) The arrival of a foreign rival to the competitive market, and (3) The government intervention in a competitive market. Three scenarios under non-cooperative Nash game are modeled and formulated for two types of solar cells, dye-sensitized and perovskite. The obtained solutions of three scenarios from the game models are put in a mathematical model for a solar cell powerhouse. In this multi-period multi-product mathematical model, the degradation of the solar cells is considered. In the meantime, solar cell powerhouse as one of the end-users of solar energy deals with the degradation by substitution solar panels. The proposed model determines how many solar panels/modules from two kinds of it should be installed and substituted in each period and which scenario to be selected. Finally, it is represented a numerical example, sensitive analysis, and management insights for the proposed model. • Developing a two-echelon multi-period multi-product solar cell supply chain (SCSC) with three scenarios. • Studying three scenarios under non-cooperative Nash game for two types of solar cells (dye-sensitized & perovskite). • Considering the degradation of the solar cell in the mixed-integer mathematical model. • The results show that the government intervention along with applying subsidy and tax has the best performance. [ABSTRACT FROM AUTHOR]

In light of the latest regulations in the energy sector, renewable energy sources are quickly becoming more important. Among renewable energy sources, the one that has the greatest potential for use in Poland is natural and waste biomass. Application of solar energy to biomass thermal conversion methods e.g., pyrolysis, affords the opportunity for additional solar energy storage as well as amplification of the pro-ecological effect of the entire conversion process. Precise control of waste biomass pyrolysis via an investigation into the process thermodynamics, kinetics, and heat transfer phenomena allows to direct the reaction for production of desirable products, ranting reduction in of disposal cost of biomass, even sewage sludge. The goal of this study was to develop new design of laboratory-scale solar pyrolytic reactors to investigate the solar pyrolysis of waste biomass. Within presented paper, pyrolysis fundamentals, including process thermodynamics and kinetic principles, were reviewed. In addition, recently-developed, and artificial-powered solar pyrolytic reactors were discussed with a brief comparison of popular light sources for solar pyrolysis studies. After numerous consultations with artificial light sources producers and researchers, own design of a solar pyrolytic reactor is presented, along with a project development, preliminary experiment results and basic methodology for future studies. • Solar pyrolysis is promising way of waste biomass conversion, free of greenhouse gases emissions. • Pyrolysis principles with emphasis on process thermodynamics and kinetics are presented. • Proper kinetic modelling of biomass pyrolysis is crucial to predict feedstock behaviour inside the reactor. • Solar pyrolysis studies performed on artificial light reactors in last 20 years are discussed. • Finally, solar pyrolysis reactor powered by 1.6 kW xenon-arc lamp, reaching 500 °C at 85.5% of lamp power is presented. [ABSTRACT FROM AUTHOR]

Economic emission dispatch (EED) problem of an electrical power system can be considered as one of the most popular constrained multi-objective optimization problems to minimize the cost and emission simultaneously subjecting to various constraints. Although many approaches have been presented to deal with this problem, it is still a challenge issue especially when more and more renewable energy sources such as wind power and solar power are incorporated into the system due to their intermittence and uncertainty. To improve the EED performance with those renewable power generations, a constrained multi-objective population extremal optimization algorithm called CMOPEO-EED is proposed by utilizing an advanced constraint handling technique, i.e., the superiority of feasible solution approach. To demonstrate the effectiveness of the proposed method, three versions of a modified IEEE 30-bus and 6-generator system with renewable power generations are considered as the test systems. The comprehensive experimental results and analyses fully validate that the proposed CMOPEO-EED method in this paper outperforms these recently reported single-objective success history based adaptive differential evolutionary algorithm (SHADE)-based EED method and constrained non-dominated sorting genetic algorithm-based EED (CNSGAII-EED) method in terms of cost and emission indices. Image 1002310 • Three cases of renewable power are incorporated for EED problem. • Superiority of feasible solutions is embedded in CMOPEO to handle constraints. • CMOPEO is developed firstly for multi-objective EED problem. • Three test systems illustrate its superiority to CNSGAII-EED and SHADE. [ABSTRACT FROM AUTHOR]

This paper reports the optimal integration of a hybrid renewable energy system consisting of wind turbines and/or photovoltaics with membrane-based seawater desalination units to meet freshwater demand. To conveniently accommodate renewable energy generation towards a cost-effective process design, the possibility of variable freshwater storage is considered. The minimization of the total cost is the objective function. The real data about renewable resources were tacking from NASA. No electrical grid connection is considered as well. The implemented model has the potential to assess to what extent variable freshwater demands can be covered by wind and solar energy under given meteorological data. As the study cases, two cities in the South of Argentina were selected: Rio Grande and Camarones. Optimal solutions obtained using solar and/or wind systems are compared in detail for both cities. Hybrid solar/wind systems obtain freshwater costs of 0.60 $/m3 to 0.66 $/m3 in both cities. [ABSTRACT FROM AUTHOR]

Abstract The aim of this study is first to make a critical evaluation of the present situation of the power system in Spain making use of the latest available data. The other main objective is to make an analysis of the optimal mix for the intensive deployment of variable renewable energies (VRES). The VRES considered are wind, solar photovoltaics (PV) and concentrating solar power (CSP), which by 2030 should provide all together about 45–50% of the total electricity demand in order to comply with the European Union (EU) Directives and the Paris 2016 Climate Agreements. As we will show, these levels of VRES would create important problems of surplus and needed backup energies, especially in the lack of sufficient electricity storage facilities. Therefore, it will be needed during the transition period the parallel use of fossil conventional backup plants, with their corresponding associated emissions. By applying linear programming optimization techniques we try in this paper to make optimal the large deployment of VRES. By "optimal" we mean that the shares of VRES would simultaneously minimize both the backup and the surplus power components for the whole set of hours (8760) in the year. For the most viable Scenario to be implemented around 2030, we have also studied the statistical distribution of slacks (surpluses and backups) so that the demand could always be covered, providing a valuable data for the provision of additional storage. In summary this scenario assumes a large reduction of coal power plants, the continuation of present nuclear power plants and the preservation of combined cycle power plants which will be used for backup due to their high flexibility and ramping speed. [ABSTRACT FROM AUTHOR]

Abstract Distributed solar photovoltaic systems are considered an important renewable energy source for meeting renewable energy targets and mitigating climate change. In several markets, emerging firms have established new business models to offer residential customers solar panel systems. In California, the third-party ownership business model has been successfully established during the last decade, and is currently spreading to other markets. Through a longitudinal case study, this paper explores how a startup firm in the Netherlands set up the third-party ownership business model on the Dutch market. The case shows that the process of bringing a business model to a new market is not sufficiently understood as a process of diffusion. Alternatively, it is a process of business model translation, in which the actors involved play a central role in adapting and successfully establishing the business model in a new market. The results have implications for both practitioners and policy makers, as well as the emerging literature on business models for sustainability. Highlights • Case study on the spread of business models for solar energy between markets. • TPO business model brought from California to the Netherlands by Dutch start-up. • Parts of TPO business model changed and adapted to fit new market circumstances. • Background and experience of entrepreneurs influence the adaptation process. • Rather than diffused, the business model is translated to fit the new market. [ABSTRACT FROM AUTHOR]

Abstract The growing integration level of wind and solar energy resources introduces new regulating and operating challenges in the electric grid. Ramp-rate limits of conventional power plants in the generation mix impose an operating constraint on renewable energy sources to the point that, at high integration levels, the ramp-rates of wind and solar resources must be managed by situational awareness tools that are based on forecasts, especially the ramp events forecasts. To leverage such tools, a post-processing adjusting approach is developed in this paper for improving the capability of hour-ahead combined forecasts of solar power to capture ramp events. The performance evaluation is conducted with several evaluation metrics that consider the accuracy of forecasts in terms of ramp events. The results of a case study demonstrate the efficacy of the adjusting approach. Probabilistic forecasts are also generated to quantify the uncertainty associated with the solar power ramp event forecasts and the uncertainty analysis is carried out. Highlights • A post-processing approach combines and improves the solar power forecasts. • The approach also adjusts the combined forecasts in terms of ramp events. • A classification of all possible thresholds and classes of ramp event forecasts. • Suitable metrics for the feature selection and the performance evaluation. • An uncertainty analysis for the probabilistic forecasts of solar power ramp events. [ABSTRACT FROM AUTHOR]

The objective of this paper is to calculate the single diode model parameters ( A , R s , R sh , I L , and I 0 ) of photovoltaic modules in most straightforward way no using iterative techniques and an additional information of pre-measured/digitized current-voltage curves. For that purpose, a new method based on solely datasheet information is introduced. The novelty of this method is to use a dark saturation current as an initial parameter as calculating the single diode model parameters. The effectiveness of proposed was validated using current-voltage curves of five commercially available photovoltaic modules at standard test conditions. The current-voltage curves were simulated using the proposed method and compared with datasheet supplied current-voltage curves by means of a root means square error tool. It has been founded that the new method, which proposes a very simple calculation procedure to obtain the single diode model parameters, meets international standards as simulating current-voltage curves of photovoltaic modules. [ABSTRACT FROM AUTHOR]

Spain must reduce its energy consumption by 23% and achieve 100% renewable energy in electricity generation by 2030. This paper presents the current energy scenario en Spain, and the outlooks for different renewable options, with special focus on photovoltaic (PV) solar energy. In 2012, Spain was the number two European country in terms of installed rewnewable energy power. Solar PV technology has the potential to meet Spain's future energy demand and its associated environmental challenges. This paper gives a review of solar energy economy at global scale for both PV and thermal power technologies. The Spanish energy scenario shows actual trends and progress made by solar power. Economic concepts of levelised cost of electricity and grid parity are presented. The financial analysis shows that PV electricity achieves grid parity at a plant profitability rate up to 7.26%. [ABSTRACT FROM AUTHOR]