Study on the Impact of Climatic and Environmental Factors on the Development and Utilization of Rooftop Solar Energy Resources in Inner Mongolia

Based on the data of 8 solar radiation stations and 119 meteorological stations in Inner Mongolia from 1961 to 2017 as well as the comparative observation of rooftop solar distributed photovoltaic power generation equipment,the impact of climatic and environmental factors on the development and utilization of rooftop solar energy resources was studied.The results show that the main climatic factors affecting rooftop solar power generation were cloud cover,precipitation,relative humidity,visibility,gale,dust weather,temperature and lightning disaster.Except for temperature and lightning disaster,other meteorological elements were negatively correlated with rooftop solar power generation,namely reducing direct radiation.The high temperature in Inner Mongolia in summer could cause the solar cell efficiency to decrease by 40%-60%,while the low temperature in eastern region in winter was not suitable for the development of rooftop solar energy resources.Lightning is the main meteorological disaster affecting the safe operation of photovoltaic systems,and class-2 lightning protection equipment needs to be installed.Photovoltaic power generation equipment should be installed on a roof which is not covered by high buildings and on the windward side of a chimney as much as possible.Areas with heavy dust pollution need to remove dust on the surface of solar panels in time.Snow and ice should be removed timely during snowfall in winter.

Solar energy full-spectrum perfect absorption and efficient photo-thermal generation

Designing and manufacturing cost-effective absorbers that can cover the full-spectrum of solar irradiation is still critically important for solar harvesting.Utilizing control of the lightwave reflection and transmission,metamaterials realize high absorption over a relatively wide bandwidth.Here,a truncated circular cone metasurface(TCCM)composed of alternating multiple layers of titanium(Ti)and silicon dioxide(SiO_(2))is presented.Enabled by the synergetic of surface plasmon resonances and Fabry-Pérot resonances,the TCCM simultaneously achieves high absorptivity(exceed 90%),and absorption broadband covers almost the entire solar irradiation spectrum.In addition,the novel absorber exhibits great photo-thermal property.By exploiting the ultrahigh melting point of Ti and SiO_(2),high-efficiency solar irradiation absorption and heat release have been achieved at 700℃when the solar concentration ratio is 500(i.e.,incident light intensity at 5×10^(5) W/m^(2)).It is worth noting that the photo-thermal efficiency is almost unchanged when the incident angle increases from 0°to 45°.The outstanding capacity for solar harvesting and light-to-heat reported in this paper suggests that TCCM has great potential in photothermal therapies,solar desalination,and radiative cooling,etc.

Thermal Energy Collection Forecasting Based on Soft Computing Techniques for Solar Heat Energy Utilization System

In recent years, introduction of alternative energy sources such as solar energy is expected. Solar heat energy utilization systems are rapidly gaining acceptance as one of the best solutions to be an alternative energy source. However, thermal energy collection is influenced by solar radiation and weather conditions. In order to control a solar heat energy utilization system as accurate as possible, it requires method of solar radiation estimation. This paper proposes the forecast technique of a thermal energy collection of solar heat energy utilization system based on solar radiation forecasting at one-day-ahead 24-hour thermal energy collection by using three different NN models. The proposed technique with application of NN is trained by weather data based on tree-based model, and tested according to forecast day. Since tree-based-model classifies a meteorological data exactly, NN will train a solar radiation with smoothly. The validity of the proposed technique is confirmed by computer simulations by use of actual meteorological data.

Solar fuel production through concentrating light irradiation

The climate crisis necessitates the development of non-fossil energy sources.Harnessing solar energy for fuel production shows promise and offers the potential to utilize existing energy infrastructure.However,solar fuel production is in its early stages of development,constrained by low conversion efficiency and challenges in scaling up production.Concentrated solar energy(CSE)technology has matured alongside the rapid growth of solar thermal power plants.This review provides an overview of current CSE methods and solar fuel production,analyzes their integration compatibility,and delves into the theoretical mechanisms by which CSE impacts solar energy conversion efficiency and product selectivity in the context of photo-electrochemistry,thermochemistry,and photo-thermal co-catalysis for solar fuel production.The review also summarizes approaches to studying the photoelectric and photothermal effects of CSE.Lastly,it explores emerging novel CSE technology methods in the field of solar fuel production.

Latest progress in hydrogen production from solar water splitting via photocatalysis,photoelectrochemical,and photovoltaic-photoelectrochemical solutions

Hydrogen production via solar water splitting is regarded as one of the most promising ways to utilize solar energy and has attracted more and more attention. Great progress has been made on photocatalytic water splitting for hydrogen production in the past few years. This review summarizesthe very recent progress (mainly in the last 2–3 years) on three major types of solar hydrogenproduction systems: particulate photocatalysis (PC) systems, photoelectrochemical (PEC) systems,and photovoltaic‐photoelectrochemical (PV‐PEC) hybrid systems. The solar‐to‐hydrogen (STH)conversion efficiency of PC systems has recently exceeded 1.0% using a SrTiO3:La,Rh/Au/BiVO4:Mophotocatalyst, 2.5% for PEC water splitting on a tantalum nitride photoanode, and reached 22.4%for PV‐PEC water splitting using a multi‐junction GaInP/GaAs/Ge cell and Ni electrode hybrid system.The advantages and disadvantages of these systems for hydrogen production via solar watersplitting, especially for their potential demonstration and application in the future, are briefly describedand discussed. Finally, the challenges and opportunities for solar water splitting solutions are also forecasted.

Recent progress on nanostructure-based broadband absorbers and their solar energy thermal utilization

Nanostructure-based broadband absorbers are prominently attractive in various research fields such as nanomaterials,nanofabrication,nanophotonics and energy utilization.A highly efficient light absorption in wider wavelength ranges makes such absorbers useful in many solar energy harvesting applications.In this review,we present recent advances of broadband absorbers which absorb light by nanostructures.We start from the mechanism and design strategies of broadband absorbers based on different materials such as carbon-based,plasmonic or dielectric materials and then reviewed recent progress of solar energy thermal utilization dependent on the superior photo-heat conversion capacity of broadband absorbers which may significantly influence the future development of solar energy utilization,seawater purification and photoelectronic device design.

Solar-heating boosted catalytic reduction of CO_(2） under full-solar spectrum

Catalytic converting CO2 into fuels with the help of solar energy is regarded as‘dream reaction’,as both energy crisis and environmental issue can be mitigated simultaneously.However,it is still suffering from low efficiency due to narrow solar-spectrum utilization and sluggish heterogeneous reaction kinetics.In this work,we demonstrate that catalytic reduction of CO2 can be achieved over Au nanoparticles(NPs)deposited rutile under full solar-spectrum irradiation,boosted by solar-heating effect.We found that UV and visible light can initiate the reaction,and the heat from IR light and local surface-plasmon resonance relaxation of Au NPs can boost the reaction kinetically.The apparent activation energy is determined experimentally and is used to explain the superior catalytic activity of Au/rutile to rutile in a kinetic way.We also find the photo-thermal synergy in the Au/rutile system.We envision that this work may facilitate understanding the kinetics of CO2 reduction and developing feasible catalytic systems with full solar spectrum utilization for practical artificial photosynthesis.

Exergy Analysis of Photo-Thermal Interaction Process between Solar Radiation Energy and Solar Receiver

A unified theory of non-equilibrium radiation thermodynamics is always in search as it is meaningful for solar energy utilization.An exergy analysis of photo-thermal interaction process between the solar radiation energy and solar receiver is conducted in this paper.The non-equilibrium radiation thermodynamic system is described.The thermodynamic process of photo-thermal interaction between the solar radiation and solar receiver is introduced.Energy,exergy and entropy equations for the photo-thermal process are provided.Formulas for calculating the optimum receiving temperatures of the solar receiver under both non-concentration and solar concentration conditions are presented.A simple solar receiver is chosen as the calculation example to launch the exergy analysis under non-concentration condition.Furthermore,the effect analysis of solar concentration on the thermodynamic performance of the solar receiver for solar thermal utilization is carried out.The analysis results demonstrate that both the output exergy flux and efficiency of the solar receiver can be improved by increasing the solar concentration ratio during the solar thermal utilization process.The formulas and results provided in this paper may be used as a theoretical reference for the further studies of non-equilibrium radiation thermodynamic theory and solar thermal utilization.

Performance Analysis of Multi-Energy Hybrid System Based on Molten Salt Energy Storage

This paper briefly summarizes the current status of typical solar thermal power plant system,including system composition,thermal energy storage medium and performance.The thermo-physical properties of the storage medium are some of the most important factors that affect overall efficiency of the system,because some renewable energy sources such as solar and wind are unpredictable.A thermal storage system is therefore necessary to store energy for continuous usage.Based on the form of storage or the mode of system connection,heat exchangers of a thermal storage system can produce different temperature ranges of heat transfer fluid to realize energy cascade utilization.Founded upon the review,a small hybrid energy system with a molten-salt energy storage system is proposed to solve the problems of heating,cooling,and electricity consumption of a 1000 m2 training hall at school.The system uses molten-salt storage tank,water tank and steam generator to change the temperature of heat transfer fluid,in order to realize thermal energy cascade utilization.Compared to the existing heating and cooling system,the proposed system needs more renewable energy and less municipal energy to achieve the same results according to simulation analysis.Furthermore,by improving the original heating and cooling system,PMV has been improved.The comprehensive efficiency of solar energy utilization has been increased to 83%.

太阳能利用工程对生态系统、生物多样性及环境的影响与应对

太阳能利用工程是减缓气候变化、实现“双碳”目标的重要措施,全面认识这些工程对生态环境的影响,对科学规划和实施工程有重要的理论和现实意义.该文总结分析了太阳能利用工程对生态系统、生物多样性与环境的影响及应对方面的研究,对存在的问题进行了讨论,并对未来的研究方向提出了展望.结果表明:①在一些太阳能利用工程区,土壤有机质和养分含量及植被盖度增加,而一些工程区却降低;工程建设对植被和土壤的干扰导致水土流失;工程占用土地和耗水及影响微气候条件等对生态系统碳排放和能量平衡造成影响;区域性布局这些工程对植被功能也将产生一定的影响,包括工程设备遮荫造成一些作物产量下降或增加.②工程设施引起的水分改变和遮荫使一些植物的丰富度增加,使一些植物种子在土壤种子库中的存活率提高,但光伏板对鸟类和昆虫等动物将会造成碰撞以及不适宜的产卵而将可能带来死亡风险;施工过程导致的植被清除和景观破碎化等对生物多样性也将造成不利影响;施工过程造成的水网损失、破碎化以及洗涤沙尘而耗水对水生生物多样性也将造成不同程度的影响;光伏板对草地土壤微生物多样性也造成一定影响.③施工期和运营期间将带来扬尘、噪声、废弃物等污染;不合理生产、利用光伏材料对生态环境也将造成负面影响.有效应对这些不利影响的措施包括:①科学规划选址,加强生物多样性保护措施的规划设计,循环利用光伏材料和加强科学管理等;②加强环境影响评价,实施生态恢复方案,加强生态系统及生物多样性保护和水土流失治理等;③发展屋顶和浮动式太阳能装置及光伏农业技术;合理选择和利用光伏材料,加强固体废弃物治理和风险管理,有效落实环境影响评价措施等.目前研究太阳能利用工程对生态系统、生物多样性与环境影响及应对方面尚不充分,随着太阳能利用工程规模的扩大,需要加强这些工程对生态系统、生物多样性及环境方面的不同影响与应对方面的研究.

Powering Renewable Programs: The Utility Perspective

In order to make renewable energy projects successful, there are many factors that utilities need to consider. These include policy drivers, assessing what renewable technologies it will employ, identifying the rates and pricing incentives that could be made available, and how customers can be better engaged. Utilities have created renewable programs with varying degrees of customer participation: some have taken the initiative to provide customers with 100% renewable generated power, others rely exclusively on customers to participate to meet renewable energy goals and the last alternative is a blend of both in which utilities offer customers the option to purchase renewable power matches or install and generate their own renewable power. Overall, the economics of solar and wind technologies are trending in the upward direction—the costs of the technologies are decreasing and the yields are getting higher. Better still, predictive modeling, energy storage and the plethora of research in this area will only make the prospects of integrating renewables more viable.

拱架送/回风方式对日光温室冬季作物冠层区热环境的影响

传统日光温室被动的热环境调控模式难以满足温室作物冠层区空气温度和速度调控需求,且能源利用效率低下。为了改进日光温室热环境精准调控方法和提高温室能源利用效率,该研究结合日光温室围护结构特点,提出了一种日光温室拱架的送/回风方法,并基于温室作物多孔介质模型,建立了拱架送/回风系统温室的数值传热模型。采用空气温度与速度不均匀系数、气流速度适宜区面积比、能量利用系数以及累计有效积温等评价参数,研究了下送上回、中间回风和上送下回等3种温室拱架送/回风方式对日光温室冬季作物冠层区热环境的影响。结果表明,与中间回风和上送下回通风方式相比,下送上回通风方式对不同作物冠层高度处的空气温度和速度调控的结果最优,且不同作物冠层高度处气流速度适宜区面积比和累计有效积温都最大。当采用下送上回通风方式时,与送风干管风速为9、11和12 m/s相比,送风干管风速为10 m/s的能量利用系数最大,在作物冠层高度0.4、0.6、0.8和1.0 m处的能量利用系数分别为0.976、0.982、0.985和0.987,并且不同作物冠层高度处的空气温度不均匀系数和速度不均匀系数也都最小。因此,下送上回通风方式的推荐送风干管风速为10 m/s。该研究可为日光温室热环境的精准调控提供参考。

CFD Simulations of Wind Effect on Net Solar Heat Gain of South Walls with Internal Insulation

Computational fluid dynamics( CFD) techniques are used to investigate effects of both wind direction and wind speed on net solar heat gain of south wall with internal insulation in winter.Results show that wind effect has a significant influence on the net solar heat gain,where the impact of wind direction is stronger than that of wind speed. For regions in lower reaches of the Yangtze River,difference of their average net solar heat gains( NSHGS) is about 20% due to various wind speeds and wind directions.Buildings in districts with a dominant wind direction of north achieve the highest solar energy utilization.

青海湟源民居太阳能利用空间性能验证及优化研究

以青海省湟源县现代民居和传统民居为研究对象,通过实地调研提取民居的被动式太阳能利用空间,分析其实际应用情况。基于太阳能利用空间的性能原理,提取出水平式阳光间、垂直式阳光间、庭院阳光间、双层墙、缓冲空间。为实现严寒条件下民居的高效节能、舒适居住的目标,借助模拟工具Design Builder软件,针对典型民居案例进行模拟验证,详细分析了水平式阳光间、垂直式阳光间、庭院阳光间、双层墙和缓冲空间的性能,并据此提出优化策略,为青海高原地区太阳能建筑技术的发展与应用提供有益指导。

集成碳捕集的1000 MW超超临界燃煤机组热力系统优化与性能研究

为降低CO_(2)的能耗并且提高发电效率,以超超临界二次再热-碳捕集系统为参考系统,提出了耦合太阳和ORC系统的二次再热-碳捕集优化方案。利用Ebsilon软件构建了优化系统模型,并进行了热力性能、经济性和运行性能分析。结果表明:与参考系统相比,优化系统热效率提高了4.78%,热耗降低了1005 kJ/(kW·h),煤耗降低了36.50 g/(kW·h);太阳能辅助系统年运行时间占比为60%,均省煤量可达到2.0×10^(4)t。优化方案具有更好的热经济性并且减少了发电耗煤量,为CO_(2)捕集和减排提供优化思路。

建筑中的“遮用阳”及其案例研究

“双碳”背景下,建筑行业不仅要注重节能,同时要强化可再生能源的利用。“遮用阳”是指将遮阳与太阳能利用(用阳)相结合的方式,既实现建筑的遮阳需求,又争取最大限度地利用太阳能资源。本研究分别梳理了遮阳的需求和太阳能利用的方式,以遮阳研究为切入点,提出了遮阳与太阳能光照、光热及光电利用结合的不同方式,并收集整理国内外的建筑设计案例,直观展示“遮用阳”的结合形式,以期在建筑设计中能够将“遮用阳”方式有效地应用。

利用光驱动的生物杂合系统实现CO_(2)转化生产化学品

太阳能作为清洁能源之一,为缓解化石燃料枯竭和温室气体排放等问题提供了一种高效、经济、可持续的解决方案.自然界中的植物和光合微生物通过自身的光合系统收集并转化太阳能,从而生产生物燃料和生物化学品.然而,由于自然光合系统存在光吸收范围相对较窄、光生电子在传输过程中易损耗等问题,限制了太阳能到化学品的转化效率.为了解决上述难题,科研人员模仿自然光合作用中的关键部分,探索构建人工光合系统,相关研究引起了广泛关注.本文通过将碲化镉量子点(CdTe QDs)与大肠杆菌(E.coli)相耦合,构建了一种光驱动无机-生物杂合系统(IBPHS),用于捕获太阳能并驱动CO_(2)转化合成高价值化学品.该系统主要由光催化模块和生物催化模块组成.在光催化模块中,通过生物合成CdTe QDs进行光能捕获,并将其转化为电子.通过敲除E.coli的Cd2+外排蛋白(ZNTA)编码基因,实现了E.coli胞内Cd2+过量积累.通过“时空耦合”方式,并借助共聚焦显微镜、高分辨率透射电镜和X射线能谱分析,确认了CdTe QDs在E.coli胞内的组装合成.利用紫外-可见分光光度计研究了光催化模块对光子的吸收能力.结果表明,光催化模块的吸收峰位于400-420 nm.利用瞬时光电流,评估了光催化模块的光生电子能力.实验发现,该模块可以产生0.07μA光电流,表明完成了光催化模块的构建.在生物催化模块中,将光催化模块产生的电子用于还原NAD+再生NADH.采用NADH生物传感器,分析了E.coli胞内NADH含量,结果表明,在蓝光照射下E.coli胞内NADH含量比黑暗条件下提高了5.1倍.在此基础上,通过表达NADH依赖型乳酸脱氢酶(LDH)将丙酮酸还原为乳酸,在蓝光光照下乳酸积累量达到了0.44 g/L,而黑暗条件下无乳酸积累,从而验证了生物催化模块的有效性.基于光催化模块和生物催化模块,进一步组装构建了IBPSH,用于驱动CO_(2)还原合成甲酸和丙酮酸.在蓝光照射下,IBPHS能够合成0.65 g/L甲酸和0.18 g/L丙酮酸,其CO_(2)利用速率分别达到51.98 mg/gDCW/h和21.92 mg/gDCW/h,超过了光合细菌.综上所述,本文利用光催化模块与生物催化模块相耦合的方式,组装构建了一种新型的人工光合系统,实现了光驱动CO_(2)还原合成高附加值化学品,为理性设计材料-生物杂合系统提供了借鉴,同时也为挖掘绿色生物制造潜力、开发太阳能化学制造平台提供参考.

太阳能被动式通风与建筑相变蓄热耦合技术研究进展

太阳能被动式通风(Solar Passive Ventilation,SPV)技术与建筑相变蓄热(Building Phase Change Heat Storage,BPCHS)技术是当前建筑节能的有效策略,两者有机结合能够显著提高太阳能利用效率、降低建筑能耗与改善室内热环境。通过对国内外有关文献调研分析,概述了太阳能被动式通风与建筑相变蓄热技术各自原理与分类,同时阐述了技术特点及其研究进展。基于太阳能被动式通风与相变蓄热在建筑应用的现状,论述了相变蓄热强化太阳能被动式通风原理及其有机耦合形式,包括相变Trombe墙、相变烟囱、相变通风屋顶等多种结合方式。此外,为了有效反映被动式通风特征与相变蓄热耦合流动-传热过程,系统总结了通风数值模型、相变蓄热求解模型以及耦合系统模型与相关实验研究。概括了太阳能被动式通风与建筑相变蓄热耦合(SPV-BPCHS)技术关键影响因素及其评价指标,指出了其对建筑室内热环境影响特性。调研结果表明,SPV-BPCHS技术能有效降低建筑能源消耗、提高太阳能建筑利用率和改善室内热环境效果,但仍应加强对高效低碳材料的研究及耦合技术稳定性研究,同时该耦合技术实验可行性也需要进一步验证。将为提高太阳能利用率和建筑室内环境耦合强化提供新的技术途径。

低纬度海岛太阳能建筑逆向热工设计方法

为了利用太阳能资源实现超低能耗建筑、创建绿色宜居的岛礁人居环境,课题组首次提出极端热湿条件下建筑“全遮阳”设计原则,创立了以太阳能光伏制冷系统与建筑防热设计相耦合的超低能耗建筑“逆向”热工设计方法,形成了适宜于低纬度海岛的超低能耗建筑新模式。实验及工程实践结果表明:全遮阳设计可大幅降低空调负荷和能耗,以南海美济岛示范建筑为例,经“全遮阳”设计后,该建筑的空调负荷可降低30%以上。若遵从逆向热工设计原则,可显著提高海洋建筑外墙、屋面和窗户的传热系数限值,实现全部依靠太阳能即可将建筑环境控制在舒适水平。低纬度海岛的超低能耗建筑新模式可有效减少对建筑设备的依赖,在建筑本体层面营造更舒适的室内热环境。

多因素耦合的光伏水泵提水系统配置优化方法

为探究提水效率影响因素及系统配置对光伏水泵提水系统性能影响,该研究利用光伏水泵循环提水系统,探究不同辐照强度、阀门开度、提水高度下光伏组件利用效率、水泵运行效率、管路效率变化规律,并构建系统流量计算模型,根据该模型计算各个区间的提水量占比及不同提水高度下提水系统的参数,根据该系统整体效率和太阳能利用率确定最优提水高度;在此基础上,通过增加光伏组件面积及蓄水池数量降低提水系统提水成本及提高太阳能利用率,并确定提水成本最低时光伏组件面积和蓄水池数量。研究结果表明:确定光伏组件利用效率随辐照强度变化关系及水泵高效率运行区间,并确定光伏水泵最优提水高度为20 m,太阳能利用率为64.05%,整体利用效率为4.521%,提水成本为0.151元/m^(3);在最优提水高度的基础上,讨论了增加光伏板面积及蓄水池数量对太阳能利用率与提水成本的影响,当提水成本最低时,光伏板面积为3.71 m2,成本为0.143元/m^(3),太阳能利用率为90.83%;蓄水池数量为4个,成本为0.145元/m^(3),太阳能利用率为94.62%,表明增加光伏板面积和蓄水池数量有效降低提水成本和提高太阳能利用率,为光伏水泵提水系统配置的优化提供新思路。