Optimisation of Electrical Distribution System by Using Solar Thermal Powered Systems and Its Impact on Electrical Distribution Feeders

In this research, the performance of the solar thermal powered systems (STPS) is analyzed with different models (without inserts, with inserts and with Nano fluids with different concentrations) and its impact on the Electric load in a residential/Institutional Electrical Distribution system. For this purpose, the electrical and solar thermal water heater is tested and validated. Solar thermal powered systems and its impact on the Institutional electrical distribution feeders are tested and compared with the energy efficiency (EE) and cost optimization. The goal of this paper is to analyze the impact of solar thermal energy on electrical energy consumption in the electrical distribution feeder level. The electrical system cost and energy consumptions are tabulated and observed that there is a considerable savings.

Utilizing Solar Thermal Energy for Post-Combustion C02 Capture

Post-combustion amine absorption and stripping can remove 90% of the CO2 from power plant flue gas, but systems can reduce electrical output by approximately 30% due to energy requirements for stripping CO2 from solvent and CO2 compression. The CO2 capture energy penalty can be reduced while developing renewable energy technologies by meeting CO2 capture energy requirements with a solar thermal energy system, particularly when electricity demand and prices are the highest. This study presents an initial review of solar thermal technologies for supplying CO2 capture energy, with a focus on high temperature systems. Parabolic troughs and central receivers are technically able to provide energy for CO2 capture. However, the solar system＇s capital costs would be roughly half that of the base coal-fired plant with CO2 capture, and high electricity prices are required to offset the costs of operating the solar thermal system. For high temperature solar thermal systems, direct electricity generation is likely a more efficient way to use solar energy to replace output lost to CO2 capture energy. However, low temperature solar thermal systems might integrate better with solvent stripping equipment, and more rigorous analysis is required to definitively assess the feasibility of using solar energy for CO2 capture.

Proposal of a Solar Thermal Power Plant at Low Temperature Using Solar Thermal Collectors

To this day, only two types of solar power plants have been proposed and built: high temperature thermal solar one and photovoltaic one. It is here proposed a new type of solar thermal plant using glass-top flat surface solar collectors, so working at low temperature (i.e., below 100°C). This power plant is aimed at warm countries, i.e., the ones mainly located between -40° and 40° latitude, having available space along their coast. This land based plant, to install on the seashore, is technologically similar to the one used for OTEC (Ocean Thermal Energy Conversion). This plant, apart from supplying electricity with a much better thermodynamic efficiency than OTEC plants, has the main advantage of providing desalinated water for drinking and irrigation. This plant is designed to generate electricity (and desalinated water) night and day and all year round, by means of hot water storage, with just a variation of the power delivered depending on the season.

A switchable concentrating photovoltaic/concentrating solar power(CPV/CSP)hybrid system for flexible electricity/thermal generation

Due to the intermittency and indeterminacy of solar irradiance,balancing energy supply and load demand remains a challenge.This paper proposed a switchable hybrid system that combines concentrating photovoltaic/concentrating solar power(CPV/CSP)technology with thermal energy storage(TES)to achieve flexible electricity and thermal generation by adjusting the incident solar flux of photovoltaic(PV).The hybrid system can directly transfer surplus solar energy into high-quality heat for storage using a rotatable PV/heat receiver.The simulated results demonstrated that the hybrid system effectively improves power generation,optimally utilizes TES capacity,and reduces the levelized cost of electricity(LCOE).Over a selected seven-day period,the single-junction(1J)Ga As solar cells used in the hybrid system sustainably satisfied the load demand for more than five days without grid supplement,outperforming the CSP plant by an additional two days.The hybrid system utilizing the 1J Ga As with the base configuration of solar multiple(SM)of 1.26 and TES capacity of 5 h improved the annual power production and renewable penetration(RP)by 20.8%and 24.8%compared with the conventional CSP plant,respectively.The hybrid plant with monosilicon and a configuration of SM(1.8),PV ratio(1),and TES capacity(6 h)achieved an optimal LCOE of11.52$ct/k Wh and RP of 75.5%,which is 8.8%lower and 12.1%higher than the CSP plant,respectively.

西藏高原村镇住宅冬季典型热电负荷特征研究

针对当前村镇住宅负荷特征表征中缺少基于用能行为差异的热电负荷关联性分析,以西藏高原村镇居住建筑为研究对象,通过走访与调研归纳出典型建筑结构特征、人员活动等信息,提炼出8种典型用能情景。利用EnergyPlus模拟计算不同用能行为下典型居住建筑全年逐时热电负荷,根据k均值聚类分析提取村镇住宅热电负荷特征,并提出基于逐时负荷系数的动态负荷典型化方法。最后基于特征参数化分析得到用能行为差异下西藏高原村镇建筑各类用户的用能特征。

考虑多类型电解槽差异化特征的分布式电热氢系统优化设计

为了提升可再生能源利用率和分布式电热氢系统的经济性和环保性,从风光发电的强波动性和多类型电解槽的差异化特征出发,建立了多类型电解槽统一模型,提出了考虑多类型电解槽差异化特征的分布式电热氢系统优化设计方法,综合利用碱性电解槽、质子交换膜电解槽以及固体氧化物电解槽在经济性、灵活性和高效性方面的差异,分别消纳不同波动特征的可再生能源。算例结果表明,该方法能够综合利用多类型电解槽的差异化特征,使多类型电解槽的运行灵活性与风光出力波动相匹配,综合提升分布式电热氢系统的经济性和环保性。

光-风电协同的低碳综合能源生产单元优化模型

为提升可再生能源发电并网消纳水平,协助传统燃煤电厂低碳化改造,推动电力系统低碳能源转型,以周孝信院士提出的综合能源生产单元架构为基础,建立光-风电协同的低碳综合能源生产单元优化模型,利用光热电站和风力发电为碳捕集系统稳定供能,减少碳捕集过程中消耗的燃煤资源。结果表明,与传统模型相比,光-风电协同的低碳综合能源生产单元优化模型将系统运行成本降低了9.6%,碳排放量降低了11.7%,产品收益提高了80.4%,具有良好的经济性与低碳性。

链式热氧化与槽式碱抛光工艺条件对PERC单晶硅太阳电池光电转换效率的影响

针对PERC单晶硅太阳电池制备工艺中3合1工序的链式热氧化工艺的氧化性能与槽式碱抛光工艺酸洗槽的去氧化能力的工艺窗口及匹配性进行了研究。首先设计实验分别测试链式热氧化工艺条件(包括温度、氧气流量)、槽式碱抛光工艺的酸洗槽液体浓度对扩散后硅片表面掺杂浓度及PERC单晶硅太阳电池光电转换效率的影响;再根据初步实验结果对链式热氧化工艺与槽式碱抛光工艺的匹配性进行分析,得到整体3合1工序的优化工艺方案;然后采用电化学微分电容电压(ECV)测试扩散后硅片表面掺杂浓度及结深的变化情况,对研究结果进行了佐证,最终达到提升PERC单晶硅太阳电池光电转换效率的目的。研究结果表明:3合1工序中的链式热氧化工艺与槽式碱抛光工艺对扩散后硅片表面掺杂浓度及PERC单晶硅太阳电池电性能存在重要影响,优化链式热氧化工艺的温度、氧气流量与槽式碱抛光工艺的酸洗槽液体浓度,提高二者的匹配性,使氧化能力与去氧化能力均达到临界点,可以最大程度地提高PERC单晶硅太阳电池的光电转换效率。

抛物面槽式太阳能集热器热损失因素研究

将太阳能热发电技术与分布式能源系统相结合,有利于加大可再生能源在能源消费结构中的比重。抛物面槽式太阳能集热器是目前太阳能热发电中应用最为广泛的太阳能-热能转化设备,其运行特性决定了太阳能热发电技术与分布式能源系统中其他能源技术是否能够相互协同。因此,针对影响槽式集热器运行特性的热损失,开展了基于现场的规模化实验系统测试工作,验证了所建槽式集热器数学模型,并且进一步应用该模型对真空区残留气体量、风速和吸热体发射率等因素开展了参数比较分析研究。

Assessment of High Concentrated Photovoltaic/Thermal Collector in Hot Climate

This work investigates the performance of combined hybrid high concentrated photovoltaic/thermal collector (HCPV/T) in Kuwait harsh climate. The proposed system consists of triple junction solar cells (InGaP/InGaAs/Ge) attached to heat source to discharge thermal energy to cooling media. Published HCPV/T models do not consider the effect of shunt resistance which greatly affects the system performance. So, a single diode model employing five parameters including the effect of shunt resistance is adapted to analyze the proposed system. To analyze the thermal performance of the proposed system, a two-dimensional thermal model based on the technique of finite difference is introduced to determine the efficiency of the hybrid HCPV/T system. The present developed subroutines are integrated with other involved codes in TRNSYS software to calculate HCPV/T system efficiency. Electrical and thermal as well as the whole system efficiency at different weather circumstances are evaluated and assessed. The effect of different weather conditions, cell temperature, concentration ratio and the temperatures of the coolant fluid on system performance are studied. Current results indicate that the model of single diode is a reliable one rather than using the two-diode complex model. Compared to measurements provided by high concentrated PV manufacturer, the current results revealed a total root mean square error of approximately 1.94%. Present predictions show that PV cell temperature has logarithmic increase with the rise in concentration ratio but with low values till concentration ratio of 400 suns after that the rise is faster at higher concentration values up to 1500 suns. Results also revealed that hybrid HCPV/T system works effectively specially in severe hot climate where thermal efficiency increases with high surrounding temperature for higher values of concentration ratio. In addition, an increase of approximately 15% in thermal efficiency and 10% in total efficiency can be achieved by utilizing active cooling device in HCPV/T system.

Assessing the Potential Use of Solar Energy Source in Urban Areas Located in Natural Protected Sites

The main aim of this paper is to present an easy to use methodology for assessing the potential amount of electricity or thermal energy production in urban areas located in natural protected sites. The methodology is based on two different steps: a territorial analysis for the evaluation of solar radiation and usable surfaces for photovoltaic or solar thermal plant, and a plant analysis for highlighting those photovoltaic and solar thermal technologies which installation will not generate significant impacts in areas characterized by high environmental and landscaping value. The methodology was successfully applied in two case studies inside two different Italian natural protected areas. The obtained results were provided to local administrations and communities as a useful tool for sustainable energy planning.

考虑电热需求响应的光热-电热综合能源系统源荷协调经济调度

负荷侧灵活性资源协同源侧多模式供热有利于电热综合能源系统低碳运行,为缓解“三北”地区“风热冲突”现象、提高风电消纳量从而降低系统碳排放量提出一种计及电热需求响应的光热-电热综合能源系统源荷协调经济调度模型。源侧通过配备储热装置的光热电站(Concentrated Solar Power,CSP)和电加热装置(Electric Heater,EH)协同热电联产机组(Combined Heat and Power,CHP)供热在一定程度上解耦其“以热定电”工作模式,网侧建立了稳态电热潮流,荷侧计及电热需求响应,模型的综合优化目标考虑了系统总运行成本、弃风惩罚成本及碳交易成本。基于改进的IEEE30电网与6节点热网系统对所建立模型进行仿真,算例结果表明源荷协调运行可有效降低系统总调度成本、提高风电并网发电量及减少系统碳排放量。

电极片检测熔盐储罐泄漏的实验研究

提出利用电极片检测熔盐储罐泄漏的方法并实验研究其可行性。结果表明,不同温度的熔盐发生泄漏时,熔盐会使电极片的回路立即形成通路,从而灵敏地检测到熔盐储罐的泄漏。并且,熔盐的运行温度越高、电极片布置位置越靠近地基材料顶部,熔盐泄漏到电极片上时导电性越强,电路中的电流越大,电极片检测熔盐罐泄漏的灵敏性和持续性越好。

Impacts of solar multiple on the performance of direct steam generation solar power tower plant with integrated thermal storage

Solar multiple （SM） and thermal storage capacity are two key design parameters for revealing the performance of direct steam generation （DSG） solar power tower plant. In the case of settled land area, SM and thermal storage capacity can be optimized to obtain the minimum levelized cost of electricity （LCOE） by adjusting the power generation output. Taking the dual-receiver DSG solar power tower plant with a given size of solar field equivalent electricity of 100 MWe in Sevilla as a reference case, the minimum LCOE is 21.77 /kWhe with an SM of 1.7 and a thermal storage capacity of 3 h. Besides Sevilla, two other sites are also introduced to discuss the influence of annual DNI. When compared with the case of Sevilla, the minimum LCOE and optimal SM of the San Jose site change just slightly, while the minimum LCOE of the Bishop site decreases by 32.8% and the optimal SM is reduced to 1.3. The influence of the size of solar field equivalent electricity is studied as well. The minimum LCOE decreases with the size of solar field, while the optimal SM and thermal storage capacity still remain unchanged. In addition, the sensitivity of different investment in sub-system is investigated. In terms ofoptimal SM and thermal storage capacity, they can decrease with the cost of thermal storage system but increase with the cost of power generation unit.

太阳能热发电项目支架隔热层厚度优化研究

针对某100 MW储热型太阳能热发电项目隔热支架,依据样本所选择隔热层厚度过大的问题,提出一种隔热层厚度的计算方法,并进行优化设计,分析隔热层厚度的主要影响因素。优化结果为隔热层的设计变更提供依据,优化后节约了项目成本,提高了项目的经济性。

不同薄膜对n型IBC太阳电池性能的影响

叉指背接触式(IBC)太阳电池因正面没有金属栅线遮挡,具有较高的光电转换效率。但由于IBC太阳电池在制备过程中需要采用光刻掩模技术进行发射极和背电场隔离,导致工艺流程复杂、电池片稳定性较差,难以实现大规模生产。研究了不同厚度的SiO_(2)薄膜、SiNx薄膜和SiO_(2)-SiNx叠层薄膜对IBC太阳电池钝化性能、减反射效果、热稳定性能和电性能的影响,实验结果表明,SiO_(2)-SiNx叠层薄膜在较宽的光谱范围内减反射效果更佳,高温热生长的20 nm厚的SiO_(2)薄膜便表现出良好的热稳定性,当选用SiO_(2)-SiNx(厚度分别为20和40 nm)叠层薄膜时,制备的IBC太阳电池光电转换效率稳定,可达24.1%,对应的开路电压为698 mV,短路电流密度为43.25 mA/cm^(2),填充因子为79.87%。

太阳能光热电站熔盐管道及其防凝设计研究

为降低系统后续跟踪运维难度系数,确保太阳能光热发电系统安全,开展太阳能光热电站熔盐管道及其防凝设计分析研究,为后续安装、施工及运维做好铺垫,保证工程的顺利进行。介绍太阳能光热电站熔盐管道的塔式太阳能光热电站熔盐管道系统与槽式太阳能光热电站熔盐管道系统,明确高温熔融盐的介质优势,重点进行太阳能光热电站二元熔盐管道及其防凝设计的分析研究,得出太阳能光热电站二元熔盐管道保温伴热系统设计与电伴热电缆安装设计、加热功率设计、结构设计结果。

采用热管冷却技术的太阳能光伏电–热一体化系统性能分析

太阳能光伏电–热(photovoltaic-thermal,PV-T)一体化系统将光伏组件与太阳能热利用系统组合在一起,具有较高的太阳能综合利用效率。针对热管具有高效传热和均温性能的特点,提出一种采用热管冷却技术的太阳能光伏电-热一体化系统;基于光伏电池板传热过程特点及换热器的传热有效度——传热单元数(ε-NTU)法,对热管式PV-T系统的电池板温度、冷却流体出口温度以及系统电效率和热效率等热电转换性能进行了理论分析和计算。结果表明,热管式PV-T系统的电池温度变化幅度在2.5℃以内,系统电效率和热效率分别达到6.99%～7.46%和51.0%～63.2%。该文提出的理论方法为研究热管式PV-T系统热电转换性能提供了一种新的途径,可用来分析和讨论相关参数对热管式PV-T系统性能的影响。

塔式太阳能热发电全寿命周期成本电价分析

塔式太阳能热发电是全球新能源近年发展的新亮点之一,成本电价高是制约其发展的主要原因。文中给出了塔式太阳能热发电站成本电价计算的全寿命周期模型,并结合建造成本、运营维护成本及发电量的预测,对影响成本电价的因素逐一分析,测算了中国塔式太阳能热发电站的预期成本电价。重点从材料、加工和安装运输3个维度对定日镜成本的变化趋势进行了分析。计算结果表明,成本电价随产能规模、单机装机容量及技术工艺因素的发展而下降,其中产能规模作用最为明显。

太阳能与风力发电的现状与展望

二十一世纪，人类期望着进入经济、社会与生态环境持续、协调、稳定发展的新时代。在我国，为满足迅速增长的能源与电力的需求，还难以扭转以煤为主的能源结构，在高效、低污染燃煤发电方面还要做出很大努力。与此同时，必须大力促进核能与太阳能（广义）的发展及其产业化，尽快改变以化石能源为主的能源结构，走上持续、协调、稳定发展的道路。本文介绍了近年来，世界与我国在太阳能热发电、太阳光发电和风力发电等方面科学、技术与应用的进展。对二十一世纪上半叶可能的进展进行了展望。