Strategic Renewable Energy Resource Selection Using a Fuzzy Decision-Making Method

Renewable energy is created by renewable natural resources such as geothermal heat,sunlight,tides,rain,and wind.Energy resources are vital for all countries in terms of their economies and politics.As a result,selecting the optimal option for any country is critical in terms of energy investments.Every country is nowadays planning to increase the share of renewable energy in their universal energy sources as a result of global warming.In the present work,the authors suggest fuzzy multi-characteristic decision-making approaches for renew-able energy source selection,and fuzzy set theory is a valuable methodology for dealing with uncertainty in the presence of incomplete or ambiguous data.This study employed a hybrid method for order of preference by resemblance to an ideal solution based on fuzzy analytical network process-technique,which agrees with professional assessment scores to be linguistic phrases,fuzzy numbers,or crisp numbers.The hybrid methodology is based on fuzzy set ideologies,which calculate alternatives in accordance with professional functional requirements using objective or subjective characteristics.The best-suited renewable energy alternative is discovered using the approach presented.

Intelligent Fractional-Order Controller for SMES Systems in Renewable Energy-Based Microgrid

An autonomous microgrid that runs on renewable energy sources is presented in this article.It has a supercon-ducting magnetic energy storage(SMES)device,wind energy-producing devices,and an energy storage battery.However,because such microgrids are nonlinear and the energy they create varies with time,controlling and managing the energy inside them is a difficult issue.Fractional-order proportional integral(FOPI)controller is recommended for the current research to enhance a standalone microgrid’s energy management and performance.The suggested dedicated control for the SMES comprises two loops:the outer loop,which uses the FOPI to regulate the DC-link voltage,and the inner loop,responsible for regulating the SMES current,is constructed using the intelligent FOPI(iFOPI).The FOPI+iFOPI parameters are best developed using the dandelion optimizer(DO)approach to achieve the optimum performance.The suggested FOPI+iFOPI controller’s performance is contrasted with a conventional PI controller for variations in wind speed and microgrid load.The optimal FOPI+iFOPI controller manages the voltage and frequency of the load.The behavior of the microgrid as a reaction to step changes in load and wind speed was measured using the proposed controller.MATLAB simulations were used to evaluate the recommended system’s performance.The results of the simulations showed that throughout all interruptions,the recommended microgrid provided the load with AC power with a constant amplitude and frequency.In addition,the required load demand was accurately reduced.Furthermore,the microgrid functioned incredibly well despite SMES and varying wind speeds.Results obtained under identical conditions were compared with and without the best FOPI+iFOPI controller.When utilizing the optimal FOPI+iFOPI controller with SMES,it was found that the microgrid performed better than the microgrid without SMES.

Hybrid Ensemble-Learning Approach for Renewable Energy Resources Evaluation in Algeria

In order to achieve a highly accurate estimation of solar energy resource potential,a novel hybrid ensemble-learning approach,hybridizing Advanced Squirrel-Search Optimization Algorithm(ASSOA)and support vector regression,is utilized to estimate the hourly tilted solar irradiation for selected arid regions in Algeria.Long-term measured meteorological data,including mean-air temperature,relative humidity,wind speed,alongside global horizontal irradiation and extra-terrestrial horizontal irradiance,were obtained for the two cities of Tamanrasset-and-Adrar for two years.Five computational algorithms were considered and analyzed for the suitability of estimation.Further two new algorithms,namely Average Ensemble and Ensemble using support vector regression were developed using the hybridization approach.The accuracy of the developed models was analyzed in terms of five statistical error metrics,as well as theWilcoxon rank-sum and ANOVA test.Among the previously selected algorithms,K Neighbors Regressor and support vector regression exhibited good performances.However,the newly proposed ensemble algorithms exhibited even better performance.The proposed model showed relative root mean square errors lower than 1.448%and correlation coefficients higher than 0.999.This was further verified by benchmarking the new ensemble against several popular swarm intelligence algorithms.It is concluded that the proposed algorithms are far superior to the commonly adopted ones.

An Overview on Advanced Grid-connected Inverters Used for Decentralized Renewable Energy Resources

并网逆变器是分散式可再生能源接入配电网的重要接口,随着分布式可再生能源渗透率的不断提高,并网逆变器在传统配电网中的地位越发突出。为了高效完成可再生能源分散式并网,并有效降低并网逆变器对电网的冲击,一些在装置上、结构上和功能上更加先进的并网逆变器成为了迫切的需求。针对现有的一些先进并网逆变器进行比较、分析和研究,从装置级、功能级和控制级的角度对现有先进并网逆变器进行综述。给出一些在结构上能更加灵活地将可再生能源分散接入配电网的硬件电路。研究一些适用于可再生能源分散接入的,使并网逆变器能虚拟同步发电机完成自治运行、电能质量治理、系统阻抗检测、网络阻抗控制等辅助控制功能。同时还对并网逆变器的并网同步算法和电流跟踪控制策略进行了探讨。最后,提出一个适合于可再生能源分散并网的先进并网逆变器框架。

Multi-objective planning model for simultaneous reconfiguration of power distribution network and allocation of renewable energy resources and capacitors with considering uncertainties

This research develops a comprehensive method to solve a combinatorial problem consisting of distribution system reconfiguration, capacitor allocation, and renewable energy resources sizing and siting simultaneously and to improve power system's accountability and system performance parameters. Due to finding solution which is closer to realistic characteristics, load forecasting, market price errors and the uncertainties related to the variable output power of wind based DG units are put in consideration. This work employs NSGA-II accompanied by the fuzzy set theory to solve the aforementioned multi-objective problem. The proposed scheme finally leads to a solution with a minimum voltage deviation, a maximum voltage stability, lower amount of pollutant and lower cost. The cost includes the installation costs of new equipment, reconfiguration costs, power loss cost, reliability cost, cost of energy purchased from power market, upgrade costs of lines and operation and maintenance costs of DGs. Therefore, the proposed methodology improves power quality, reliability and security in lower costs besides its preserve, with the operational indices of power distribution networks in acceptable level. To validate the proposed methodology's usefulness, it was applied on the IEEE 33-bus distribution system then the outcomes were compared with initial configuration.

China puts more money in renewable energy resources

In 2010, over 300 billion yuan ($47.31 billion) are invested in renewable energy sources in China, outranking every other country. Hence, China has become one of the world’s biggest investors in renewable energy sources.

Tapping Renewable Energy Resources -with A Combined Capacity of 1236 MW as Target for the Year 2000

China began the research and development of renewable energy generation since 1970s, in particular in the Eighth Five-year Plan period, the State made closer attention to the research and development of renewable energy, therefore the technical level, application scale and economic, social benefits have seen greater progress. The combined capacity of renewable energy generation reached 100 MW at the end of 1994. And it is planned a combined capacity of 1236 MW will be targeted for the year 2000.

Study of the development road map of China’s renewable energy

Renewable energy (RE) has been attached high attention around the world due to its carbon-free and indigenous production in a sustainable way. China enjoys plenty of renewable energy resources, particularly the wind, solar, hydro- and biomass energy, which could be a sound basis for a large-scale exploitation. This report examines the current status of RE technology and industry, analyzes the challenges of promoting RE in China. In order to pave the way for a long-term development of RE, this paper outlines the basic principles and priorities for individual RE technology. In line with these, the paper puts forward the RE targets and further describes the RE road map by 2020, 2030 and extend to 2050, taking consideration of China’s RE resources, industrial basis and energy demand etc. At last, this paper provides some recommendations to ensure the achievements of the RE targets.

Communication Resources Allocation for Time Delay Reduction of Frequency Regulation Service in High Renewable Penetrated Power System

The high renewable penetrated power system has severe frequency regulation problems.Distributed resources can provide frequency regulation services but are limited by com-munication time delay.This paper proposes a communication resources allocation model to reduce communication time delay in frequency regulation service.Communication device resources and wireless spectrum resources are allocated to distributed resources when they participate in frequency regulation.We reveal impact of communication resources allocation on time delay reduction and frequency regulation performance.Besides,we study communication resources allocation solution in high renewable energy penetrated power systems.We provide a case study based on the HRP-38 system.Results show communication time delay decreases distributed resources'ability to provide frequency regulation service.On the other hand,allocating more communication resources to distributed resources'communica-tion services improves their frequency regulation performance.For power systems with renewable energy penetration above 70%,required communications resources are about five times as many as 30%renewable energy penetrated power systems to keep frequency performance the same.Index Terms-Communication resources allocation,commun-ication time delay,distributed resource,frequency regulation,high renewable energy penetrated power system.

Energy Economic Dispatch for Photovoltaic-Storage via Distributed Event-Triggered Surplus Algorithm

This paper presents a novel approach to economic dispatch in smart grids equipped with diverse energy devices.This method integrates features including photovoltaic(PV)systems,energy storage coupling,varied energy roles,and energy supply and demand dynamics.The systemmodel is developed by considering energy devices as versatile units capable of fulfilling various functionalities and playing multiple roles simultaneously.To strike a balance between optimality and feasibility,renewable energy resources are modeled with considerations for forecasting errors,Gaussian distribution,and penalty factors.Furthermore,this study introduces a distributed event-triggered surplus algorithm designed to address the economic dispatch problem by minimizing production costs.Rooted in surplus theory and finite time projection,the algorithm effectively rectifies network imbalances caused by directed graphs and addresses local inequality constraints.The algorithm greatly reduces the communication burden through event triggering mechanism.Finally,both theoretical proofs and numerical simulations verify the convergence and event-triggered nature of the algorithm.

Stochastic Security-constrained Unit Commitment Considering Electric Vehicles, Energy Storage Systems, and Flexible Loads with Renewable Energy Resources

In this paper, a new formulation for modeling the problem of stochastic security-constrained unit commitment along with optimal charging and discharging of large-scale electric vehicles, energy storage systems, and flexible loads with renewable energy resources is presented. The uncertainty of renewable energy resources is considered as a scenario-based model. In this paper, a multi-objective function which considers the reduction of operation cost, no-load and startup/shutdown costs, unserved load cost, load shifting, carbon emission, optimal charging and discharging of energy storage systems, and power curtailment of renewable energy resources is considered. The proposed formulation is a mixed-integer linear programming(MILP) model, of which the optimal global solution is guaranteed by commercial solvers. To validate the proposed formulation, several cases and networks are considered for analysis, and the results demonstrate the efficiency.

Optimal Day-ahead Dynamic Pricing of Grid-connected Residential Renewable Energy Resources Under Different Metering Mechanisms

Nowadays,grid-connected renewable energy resources have widespread applications in the electricity market.However,providing household consumers with photovoltaic(PV)systems requires bilateral interfaces to exchange energy and data.In addition,residential consumers’contribution requires guaranteed privacy and secured data exchange.Dayahead dynamic pricing is one of the incentive-based demand response methods that has substantial effects on the integration of renewable energy resources with smart grids and social welfare.Different metering mechanisms of renewable energy resources such as feed-in tariffs,net metering,and net purchase and sale are important issues in power grid operation planning.In this paper,optimal condition decomposition method is used for dayahead dynamic pricing of grid-connected residential renewable energy resources under different metering mechanisms:feed-intariffs,net metering,and net purchase and sale in conjunction with carbon emission taxes.According to the stochastic nature of consumers’load and PV system products,uncertainties are considered in a two-stage decision-making process.The results demonstrate that the net metering with the satisfaction average of 68%for consumers and 32%for the investigated electric company leads to 28%total load reduction.For the case of net purchase and sale mechanism,a satisfaction average of 15%for consumers and 85%for the electric company results in 11%total load reduction.In feed-in-tariff mechanism,in spite of increased social welfare,load reduction does not take place.

Environmental impact of energy imports:Natural resources income and natural gas production profitability in the Asia-Pacific Economic Cooperation Countries

Environmental degradation is a pressing global concern,with the energy sector being one of the major contributors to this issue.The environmental impact of energy imports,particularly regarding natural resources income and natural gas production profitability,cannot be ignored.Countries must assess the environmental consequences of their energy choices and take steps to minimize their impact.By transitioning to cleaner and more sustainable energy sources,countries can ensure a better future for the environment and their economies.This study examines the impact of energy imports and natural resources income on environmental degradation in the Asia-Pacific Economic Cooperation(APEC)countries from 1990 to 2020,using revenue minus the production cost of natural gas and electricity production from renewable sources as moderating variables.Long-run estimates are derived using the Generalized Method of Moments and robust least squares.Our findings elucidate that importing energy from countries specializing in renewable energy can help reduce reliance on fossil fuels.This diversification of energy sources decreases the overall carbon footprint and contributes to a cleaner environment.Natural gas production often involves infrastructure construction,such as drilling rigs and pipelines,which can disrupt natural habitats and wildlife corridors.This destruction of ecosystems can have long-term consequences on biodiversity and ecological balance.The environmental impact of energy imports,particularly related to natural resource income and natural gas production profitability,requires BRICS countries to take proactive measures.These nations can address the environmental challenges associated with their energy demands by implementing policies prioritizing sustainable resource management,carbon pricing,stringent regulation,and investment in research and development.By doing so,they can balance economic growth and environmental sustainability,ensuring a greener future for the BRICS countries.

Evaluation and re-understanding of the global natural gas hydrate resources

Natural gas hydrate(NGH)has been widely considered as an alternative to conventional oil and gas resources in the future energy resource supply since Trofimuk’s first resource assessment in 1973.At least 29 global estimates have been published from various studies so far,among which 24 estimates are greater than the total conventional gas resources.If drawn in chronological order,the 29 historical resource estimates show a clear downward trend,reflecting the changes in our perception with respect to its resource potential with increasing our knowledge on the NGH with time.A time series of the 29 estimates was used to establish a statistical model for predict the future trend.The model produces an expected resource value of 41.46×1012 m3 at the year of 2050.The statistical trend projected future gas hydrate resource is only about 10%of total natural gas resource in conventional reservoir,consistent with estimates of global technically recoverable resources(TRR)in gas hydrate from Monte Carlo technique based on volumetric and material balance approaches.Considering the technical challenges and high cost in commercial production and the lack of competitive advantages compared with rapid growing unconventional and renewable resources,only those on the very top of the gas hydrate resource pyramid will be added to future energy supply.It is unlikely that the NGH will be the major energy source in the future.

An Analysis of Renewable Water Sources in Saudi Arabia

Kingdom of Saudi Arabia (KSA) is located in a very harsh natural desert environment with no rivers or lakes and an average yearly rainfall of less than 100 mm. The country is under extreme water shortage conditions. KSA utilizes conventional (natural) and unconventional water resources to satisfy the ever increasing water demand. The purpose of this paper is to analyze two approaches to obtaining fresh water from renewable water resources, namely they are seawater distillation using solar energy and gathering liquid water from fog. In order to conduct the study for seawater distillation a solar still basin has been designed, manufactured and tested in selected day for saline water in month of April, 2012. The solar still consists of insulated metal box with channels. Pyramidal glass covers attached to the basin at an angle (=45°), and the basin area of the still is 0.25 m2 and filled with 6 liters of seawater. The average daily output was found to be 3.924 liters/day. Further, to harvesting water from fog a Standard Fog Collector (SFC) was designed and manufactured in Asir region with locally available materials and imported mesh. This SFC was installed in April 2012. The site was chosen based on topography and altitude and data from April 2012 to March 2013 were obtained. Measurements with the SFC were made for region with 3200 m elevation. The results indicate that the average water production was 6.225 L/(m2·day) over the studied period and the highest average water production was recorded in December 11.20 L/(m2·day). The highest water collection was 20 L/(m2·day) and recorded in Jan. 05, 2013 at Rayda site, and furthermore for the same site, the best average water production of 10.52 L/(m2·day) was obtained in winter three months period namely (December, November and January).

Bioeconomy in the Agrarian Resources Potential System of Ukraine

The main goal of this research is to determine the importance and prospects of bioeconomy development in agriculture of Ukraine for international economic integration.Actual reason for this research is military occupation of west regions and the macroeconomic instability.Available resources form supply potential for agrarian production,renewable energy,and sustainable development.However,unemployment of labour,land,and capital determine the inflationary gap,which could be closed in two main ways:The innovative economic growth in business and households’sectors in accordance to bio-based principles and rational government state regulation with fiscal and monetary policies instruments.The external and internal effects of bioeconomy development in the agrarian resources system are determined in accordance to strengths,weaknesses,opportunities,and threats(SWOT)-analysis.European integration requires entrepreneurial initiative,environmental protection,social benefits in the satisfaction of individual needs of the population,modern principles of competition,such as mutual beneficial cooperation and new market creation for food security and human resources development.

水风光大基地资源分析要求和方法

近年来,由于“极热无风”“晚峰无光”“云来无光”“冬季枯水”甚至极端天气导致的“汛期反枯”等气象问题加剧了能源保供的压力,能源开发方式将不能局限于单一能源品种,而应呈现多能互补方式,清洁可再生的“水风光”多能互补开发,可以最大程度地带动流域内风光资源的开发利用,弥补新能源发电的出力不足,是保障电量可靠供给的有效方式。水风光资源的特性与时空分布是水风光多能互补规划设计和调度运行的基础与依据,本文首先论述了水风光资源特性及其评估方法,进而开展对水风光互补特性的研究,最后针对水风光大基地在规划设计和调度运行中的资源分析方法进行论述。

Optimal Operation of an Integrated Electricity-heat Energy System Considering Flexible Resources Dispatch for Renewable Integration

Large fluctuations may occur on the energy supply and the load sides when large-scale renewable energies are integrated,leading to great challenges in power systems.The renewable power curtailment is especially numerous in the integrated electricity-heat energy system(IEHES)on account of electricity-heat coupling.The flexible resources(FRs)on both the energy supply and load sides are introduced into the optimal dispatch of the IEHES and further modeled to alleviate the renewable fluctuations in this paper.On the energy supply side,three kinds of FRs based on electricity-heat coordination are modeled and discussed.On the load side,the shiftable electricity demand resource is characterized.On this basis,the solution for FRs participating in IEHES dispatch is given,with goals of maximizing the renewable penetration ratio and lowering operation costs.Two scenarios are performed,and the results indicate that the proposed optimal dispatch strategy can effectively reduce the renewable energy curtailment and improve the flexibility of the IEHES.The contribution degrees of different FRs for renewable integration are also explored.