Hybrid Renewable Energy Resources Management for Optimal Energy Operation in Nano-Grid

Renewable energy resources are deemed a potential energy production source due to their cost efficiency and harmless reaction to the environment, unlike non-renewable energy resources. However, they often fail to meet energy requirements in unfavorable weather conditions. The concept of Hybrid renewable energy resources addresses this issue by integrating both renewable and non-renewable energy resources to meet the required energy load. In this paper, an intelligent cost optimization algorithm is proposed to maximize the use of renewable energy resources and minimum utilization of non-renewable energy resources to meet the energy requirement for a nanogrid infrastructure. An actual data set comprising information about the load and demand of utility grids is used to evaluate the performance of the proposed nanogrid energy management system. The objective function is formulated to manage the nanogrid operation and implemented using a variant of Particle Swarm Optimization (PSO) named recurrent PSO (rPSO). Firstly, rPSO algorithm minimizes the installation cost for nanogrid. Thereafter, the proposed NEMS ensures cost efficiency for the post-installation period by providing a daily operational plan and optimizing renewable resources. State-of-the-art optimization models, including Genetic Algorithm (GA), bat and different Mathematical Programming Language (AMPL) solvers, are used to evaluate the model. The study's outcomes suggest that the proposed work significantly reduces the use of diesel generators and fosters the use of renewable energy resources and beneficiates the eco-friendly environment.     

Solar pond technology

Solar pond technology has made substantial progress in the last fifteen years. This paper reviews the basic principles of solar ponds and the problems encountered in their operation and maintenance. The factors which influence the technical and economic viability of solar ponds for thermal applications and power generation have been discussed.     

太阳能采暖设计探讨

概括太阳能利用现状,结合项目实例,介绍了某佛学院主动式太阳能采暖结合被动式太阳房系统的设计,对太阳能采暖系统设计中存在的问题进行探讨。     

太阳能选择性涂层的研制

分析了太阳能选择性吸收涂层的光学性能 ,介绍了利用电解着色方法制备Sn/Al2 O3 复合涂层的实验过程 ,报道了利用扫描电镜和俄歇能谱仪测量的结果     

Solar passive buildings for developing countries

This paper is meant to be an indicative survey of developments in solar passive building technology relevant to developing countries. The evolution of this area during the last fifty years is reported along with the scientific principles and design concepts underlying these developments. Factors to be considered for design strategies such as direct gain, isolated gain, indirect gain and roof evaporative systems are then described. Rating parameters for assessing the performance and benefit and cost parameters are then outlined. Successful examples illustrating each of the design concepts, mainly from Indian buildings constructed during the last fifteen years, are then detailed along with their performance based on actual monitoring, if available. Concluding remarks indicate the current and future trends. A survey is made of papers marking significant milestones in the development of solar passive building technology relevant to developing countries.     

太阳能在空调制冷系统中的研究现状及应用前景

随着空调能耗的日益增大，太阳能在空调制冷领域的应用已成为现代空调制冷技术研究的热点和重要发展方向。本文对近年来太阳能在吸收式、吸附式、喷射式等空调制冷技术等方面的研究进展进行了总结，并分析了其发展前景，认为在提高太阳能制冷技术效率及降低初投资成本后，将在空调制冷领域有广阔的应用前景。     

Solar Energy Materials

Solar energy materials have properties tailored to meet requirements set by the spectral distribution, angle of incidence, and intensity of the electromagnetic radiation prevailing in our natural surroundings. Specifically, the optimization can be performed with regard to solar irradiation, thermal emission, atmospheric absorption, visible light, and photosynthetic efficiency. Materials for thermal and electrical conversion of solar energy in man‐made collectors, as well as for energy‐efficient passive design in architecture, are typical examples. This paper reviews solar energy materials with emphasis on the thermal applications of a variety of types. Electrical applications are given a more cursory exposition, the reason being that a systems perspective—rather that a materials perspective—is most fruitful in this case.     

Optimal Implementation of Photovoltaic and Battery Energy Storage in Distribution Networks

Recently, implementation of Battery Energy Storage (BES) with photovoltaic (PV) array in distribution networks is becoming very popular in overall the world. Integrating PV alone in distribution networks generates variable output power during 24-hours as it depends on variable natural source. PV can be able to generate constant output power during 24-hours by installing BES with it. Therefore, this paper presents a new application of a recent metaheuristic algorithm, called Slime Mould Algorithm (SMA), to determine the best size, and location of photovoltaic alone or with battery energy storage in the radial distribution system (RDS). This algorithm is modeled from the behavior of SMA in nature. During the optimization process, the total active power loss during 24-hours is used as an objective function considering the equality and inequality constraints. In addition, the presented function is based on the probabilistic for PV output and different types of system load. The candidate buses for integrating PV and BES in the distribution network are determined by the real power loss sensitivity factor (PLSF). IEEE 69-bus RDS with different types of loads is used as a test system. The effectiveness of SMA is validated by comparing its results with those obtained by other well-known optimization algorithms.     

太阳能与常规能源复合空调/热泵系统在别墅建筑中的应用研究

为实现太阳能在绿色节能建筑中的应用,根据别墅建筑特点,结合溴化锂吸收式制冷／热泵系统的特点,提出太阳能与常规能源复合的空调／热泵系统。系统内采用了潜能储存和常规莆能综合技术,提高了系统的蓄能密度,并解决了吸收式热泵系统运行必须有16℃以上热源的问题。系统可为别墅建筑提供夏季空调,冬季采暖以及全年的卫生用水。建立了太阳能综合系统运行特性分析的计算模型,并以北京、西安、兰州三处太阳能较为丰富的地区为例,结合气候条件对系统运行特性进行了计算分析,给出了系统内能量分配与平衡的关系,并对系统运行作了简要的经济性评价。     

浅谈我国能源现状和水电资源利用的飞速发展

面对化石能源逐渐枯竭的现状,积极开发和使用新能源和可再生能源,实施可持续发展的能源政策已成为我国今后能源开发战略的基本选择。本文分析了我国能源面临的形势和挑战;介绍了我国可再生能源的利用状况及发展规划;详细阐述了我国水电能资源的发展情况。我国是一个水能资源丰富的国家,近几十年来,我国的水电事业取得了举世瞩目的成就,极大地推动了我国的经济发展和社会进步。     

Optimal Selection of Hybrid Renewable Energy System Using Multi-Criteria Decision-Making Algorithms

Several models of multi-criteria decision-making (MCDM) have identified the optimal alternative electrical energy sources to supply certain load in an isolated region in Al-Minya City, Egypt. The load demand consists of water pumping system with a water desalination unit. Various options containing three different power sources: only DG, PV-B system, and hybrid PV-DG-B, two different sizes of reverse osmosis (RO) units; RO-250 and RO-500, two strategies of energy management; load following (LF) and cycle charging (CC), and two sizes of DG; 5 and 10 kW were taken into account. Eight attributes, including operating cost, renewable fraction, initial cost, the cost of energy, excess energy, unmet load, breakeven grid extension distance, and the amount of CO₂, were used during the evaluation process. To estimate these parameters, HOMER^® software was employed to perform both the simulation and optimization process. Four different weight estimation methods were considered; no priority of criteria, based on a pairwise comparisons matrix of the criteria, CRITIC-method, and entropy-based method. The main findings (output results) confirmed that the optimal option for the case study was hybrid PV-DG-B with the following specification: 5 kW DG, RO-500, and load following control strategy. Under this condition, the annual operating cost and initial costs were $ 5546 and $ 161022, respectively, whereas the cost of energy was 0.077 $/kWh. The excess energy and unmet loads were 40998 and 2371 kWh, respectively. The breakeven grid extension distance and the amount of CO₂ were 3.31 km and 5171 kg per year, respectively. Compared with DG only, the amount of CO₂ has been sharply reduced by 113939 kg per year.     

太阳能热泵技术在中央热水系统中的应用

随着能源价格的上涨，太阳能的利用问题越来越引起人们的重视。本文主要介绍太阳能热泵装置的工作原理及技术特点，对太阳能热泵中央热水系统的效率进行分析，提出应大力推广太阳能热泵技术在我国的应用。     

一种新型的太阳能与地源热泵联合运行系统

本文分析了太阳能与地源热泵的技术优点及存在的问题，针对目前常规太阳能与地源热泵联合运行系统的缺陷，构思出了一套以生态理念构建的复合式新型能源系统。进而论述了该新型能源系统的工作方式，并阐述了该新系统的技术经济性。最后指出研究及开发中存在的问题，展望了其应用前景。     

太阳能热水系统与跨临界二氧化碳热泵系统双向优化组合

太阳能是可再生能源。它资源丰富,既可免费使用,又无需运输,对环境无任何污染。为了促进节能与环境保护,太阳能热水系统已得到广泛应用。二氧化碳作为制冷工质具有一些独特的优势:环境友好物质(ODP=0,GWP=1),无回收问题;良好的安全性和化学稳定性;具有与制冷循环和设备相适应的热力学性质;具有良好的输运和传热性质。与常规制冷剂相比,二氧化碳跨临界循环的压缩比较小,约为2.5～4.0。介绍一种太阳能热水系统与跨临界二氧化碳热泵系统的组合系统,包括太阳能热水系统,二氧化碳热泵系统。针对不同气候条件,本系统分别采用制冷、热水、制热运行模式,从而实现热水、空调与热泵三大功能。     

反射式GaAs光电阴极的热增强光电发射能量转换理论研究

热增强光电发射是一种新的太阳能转换技术,它可以将光电发射和热电发射结合到一个过程中。本文在细节平衡条件下对光子增强热电子发射进行了理论计算,并给出了反射式GaAs光电阴极的增强热电子发射电流密度和能量转换效率。计算结果表明,阴极的电子亲和势增高会降低发射电流密度,提高输出电压,影响能量转换效率。当电子亲和势为负时,平台期能量转换效率约为15%,当电子亲和势为正时,能量转换效率可以超过25%。实验测得反射式GaAlAs/GaAs真空光电二极管的光电发射过程随温度提高而增强,在短波段更为明显。若以低功函数金刚石薄膜为阳极,可计算其能量转换效率约为2.7%,并随温度提高而略有提升。     

Toward an Aqueous Solar Battery: Direct Electrochemical Storage of Solar Energy in Carbon Nitrides

Graphitic carbon nitrides have emerged as an earth‐abundant family of polymeric materials for solar energy conversion. Herein, a 2D cyanamide‐functionalized polyheptazine imide (NCN‐PHI) is reported, which for the first time enables the synergistic coupling of two key functions of energy conversion within one single material: light harvesting and electrical energy storage. Photo‐electrochemical measurements in aqueous electrolytes reveal the underlying mechanism of this “solar battery” material: the charge storage in NCN‐PHI is based on the photoreduction of the carbon nitride backbone and charge compensation is realized by adsorption of alkali metal ions within the NCN‐PHI layers and at the solution interface. The photoreduced carbon nitride can thus be described as a battery anode operating as a pseudocapacitor, which can store light‐induced charge in the form of long‐lived, “trapped” electrons for hours. Importantly, the potential window of this process is not limited by the water reduction reaction due to the high intrinsic overpotential of carbon nitrides for hydrogen evolution, potentially enabling new applications for aqueous batteries. Thus, the feasibility of light‐induced electrical energy storage and release on demand by a one‐component light‐charged battery anode is demonstrated, which provides a sustainable solution to overcome the intermittency of solar radiation.     

新型太阳能热水站与太阳能制冷空调综合系统设计探讨

介绍通过热水需求量来确定空调负荷供应量的太阳能空调和热水站综合系统,建立常年生活热水和夏季空调冷水综合应用的太阳能利用系统.提出几点不足.     

Fuzzy Multi-Criteria Decision Making for Solar Power Plant Location Selection

Vietnam is one of Southeast Asian countries with a rapid GDP growth rate, ranging from 6.5% to 7% annually, leading to an average increase in energy demand of 11% per year. This demand creates many new opportunities in the energy industry, especially renewable energy, to ensure sustainable development in the future for the country with applications of solar energy growing at the present, and other opportunities to expand in the future. In Vietnam, thanks to favorable weather, climate, terrain characteristics and many preferential support policies, there are many great opportunities in the field of solar energy exploitation and application. Location selection is an important problem in all renewable energy projects. Therefore, the author proposed a fuzzy Multi-criteria Decision-Making Model (MCDM) model for solar power plant location selection in this study, and as a result, location 5 is the optimal solution. The contribution of this study is to propose a MCDM for solar power plant location selection in Vietnam under fuzzy environmental conditions.     

热泵在开发可再生能源领域的作用及其贡献率的计算方法

热泵是可再生能源的"开采机械",可以用一份电能或机械能,得到数倍的可再生能源,是重要的节能和环保技术。随着我国能源需求剧增和电力工业的快速发展,需要提高我国可再生能源的比例,热泵技术有着极其重要的作用。本文介绍了欧盟把热泵技术列为可再生能源的政策,进而说明了我国相应的政策。通过对我国燃煤电厂的发电效率和电网的输电效率的数据进行分析,得出热泵是获得可再生能源的一种技术。文中提出了我国热泵一次能源倍数α和可再生能源贡献率β两种计算方法供业内参考。由于电厂的烟气排放指标远比一般燃煤锅炉严格得多,用热泵代替燃煤锅炉可改善大气质量。因此本文建议把热泵可再生能源贡献率的计算方法写入国家标准,以促进我国热泵制造产业,大力推广热泵节能技术。     

热管真空管太阳能集热器研究进展及应用

太阳能集热装置是将太阳辐射能转换为热能的设备,国内外学者对太阳能集热器的核心部件之一的真空管进行了广泛研究。本文首先介绍了热管真空管集热器工作原理并对部分影响集热器性能的性能指标、主要技术参数等进行探讨;其次分析了热管真空管集热器在使用中存在的问题并提出了解决途径,再次讨论了热管真空管太阳能集热器的应用;最后从集热器结构、换热器内工质及性能参数等方面提出了改进热管真空管太阳能集热器性能的方式。