屋顶计划催生光伏瓦

1前言 自从“屋顶计划”在美、德、日等国家实施以来，光伏产业在其政府政策强力推动下得到了迅速发展，屋顶发电的潜力凸现，商机无限。然而，标准光伏组件（无论是尺寸还是容量规格）并不适合安装在形式各异的普通屋面上，于是随着光伏建筑一体化（BIPV）理念的提出，一种光伏发电与建筑相结合的新产品——光伏瓦应运而生。理想的光伏瓦应满足以下条件：（a）适合普通屋顶的施工包括安装方法简易以及容易与屋顶融合为一体；（b）发电及与普通瓦片一样的建筑功能。     

绿色建筑标准下光伏发电系统屋面敷设面积比例分析

在绿色建筑标准要求下,对太阳能光伏发电系统提供电量比例进行了分析,结果表明λ(组件安装面积与标准层面积比值)与Q0(单位建筑面积用电负荷)、ηi(组件转换效率)及n(标准层楼层数)相关.在屋面面积有限的情况下,研究结果可为屋面光伏系统的敷设比例提供设计指导.     

浅谈金属屋面光伏发电系统的安装

通过对金属屋面上的光伏并网电站组件安装方式的介绍,分析了金属屋面上光伏组件的设计、安装及维护。     

植物布置模式对光伏组件和屋面被动降温及水分蒸发的影响

绿色光伏屋顶是一种光伏组件遮阳与植被绿化相结合的隔热屋顶,为了揭示植物布置模式对光伏组件和屋面降温的影响,提出了2种植物布置模式并建立了2个混凝土屋顶试验小室。分别对光伏组件背面和屋面上表面温度、植物叶片温度和蒸发量进行测试和对比分析。结果表明：1）相对于植物架空布置模式,植物直接实铺在屋面上可有效降低屋面上表温度平均值和波幅值;2）植物与光伏组件背面距离增加时会减弱其对光伏组件的冷却效果,间距为10 cm时冷却效果较为明显;3）植物与光伏组件背面距离变小时,叶片温度会变高,水分蒸发量变多。因此,植物直接实铺模式有利于绿植光伏屋面节水和节能。     

上海太阳能光伏一体化屋面应用现状

概述了上海光伏一体化屋面从与屋面结合安装到实现建材化和构件化的发展,并以崇明瀛东生态村项目为例介绍了光伏构件化屋面的设计、实施以及效果测评.     

屋顶分布式光伏发电项目坠落防护的探讨与实践

屋顶分布式光伏发电以其灵活、安装方便且可充分利用被闲置屋面的特点,受到各地政府和企业的青睐。随着碳达峰、碳中和目标的提出,屋顶分布式光伏发电已经在各地掀起了一场安装热潮,但随着屋顶分布式光伏发电的推广和普及,此类项目安装和运维过程中的屋面坠落风险也随之而来。探讨了中国屋顶分布式光伏发电项目坠落防护的现状,针对目前坠落防护措施缺失或不足的现状,引入基于风险控制的管理思路,结合目前国内有关坠落防护的相关要求及已有项目的实际情况,针对不同的屋面坠落场景提出了具体的坠落防护措施和建议,以期为屋顶分布式光伏发电项目坠落防护的标准化、规范化提供更多思路。     

上海市分布式光伏发电发展规划研究

在对本市太阳能光伏项目建设情况进行全面的调研与分析的基础上,明确了本市太阳能光伏发展的阶段与方向;并对本市光伏资源进行了进一步评估分析,其中包括本市太阳能辐射资源与建筑屋顶资源情况,经测算,本市约共有2亿m2的屋顶面积,其中可加以利用的屋顶约占40%,经对其建筑功能类型的组成结构分析后,提出本市大力推进分布式光伏发电的实施途径是先工业建筑再公共建筑,然后再别墅等居住建筑,建设类型分先新建建筑再既有建筑的实施路径,并结合本市目前城市建设重点,提出了规划布局建议。     

屋顶分布式光伏发电工程总承包管理实践经验

在新能源政策的促进下,中国光伏发电的装机容量、发电量持续提高.屋顶分布式光伏发电系统的优点是可以就近解决用户的用电问题,可充分利用建筑物屋面,减少土地面积的占用,且屋顶分布式光伏发电项目建设期间不影响项目所在企业的正常生产,因此该类光伏发电项目的建设规模稳步增长,区域构建超前性与实用性相结合.从总承包管理的角度,针对屋...     

粮仓光伏发电系统设计与分析

基于机械制冷低温储粮过程中耗电量大的特点及粮仓建筑屋顶面积大、无遮阳等具有可利用光伏屋顶发电的有利条件,研究了粮仓零能耗低温储粮技术。本文以安徽省合肥市国家粮库某粮仓为例,从气象条件、系统运行方式、太阳能电池方阵设计及安装和并网电气设计等方面综合设计了为低温储粮提供能源来源的粮仓光伏屋顶发电系统。系统直流总功率为162 kW,并辅助使用RETscreen清洁能源项目分析软件得到系统每年发电量为166.3 MWh。最后进行了系统节能减排效益分析,其能在静态回收期内节省标煤582 t,减排CO21 610 t。     

分布式光伏屋顶电站轻量化组件封装及轻型安装方式

受分布式屋顶光伏电站屋顶载荷的限制、屋顶出租方对屋顶防水层限制破坏性施工的要求、彩钢瓦屋顶的特殊结构、组件和电站高可靠性、低成本要求等,在对光伏组件密封和安装粘接材料技术研究、以及国内外同类材料的对比试验基础上,本文简要介绍了几种高性能封装技术的轻量化光伏组件,着重介绍了其轻型安装方式,对分布式屋顶电站安装建设中一些常见的应用案例进行了论述、分析和优缺点对比。     

晶硅光伏系统在高层建筑屋顶的应用探讨

晶硅光伏系统在高层屋顶上应用较为普遍,但由于受到风荷载、运输、加固、荷载、经济性等各方面的影响,在我国高层建筑中,目前应用还不广泛。本文主要通过对高层建筑屋顶上建设光伏系统各类影响因素的计算和量化分析,剖析高层建筑采用晶硅光伏系统的合理性,并最终给出相应建议。     

小型菲涅尔式CPV/T集热器光热特性研究

为充分利用建筑屋顶,解决光伏光热一体化(PV/T)集热器光电转换效率的高温减益问题,并提高太阳能综合利用率和集热品位,文章构建了一种基于太阳光谱分频利用技术的光伏/光热模块分离式的小型聚光式PV/T集热器。通过建立其光/电/热理论分析模型及TracePro/Fluent数值仿真模型,以南京地区气象数据为例,综合分析其光/电/热性能,结果表明:该集热器以与安装地纬度等值的倾角南北轴向放置时,其年均光学效率为64.97%,工质出口温度为90℃时的系统光电/光热效率分别为12.47%,40.09%,系统综合热效率达72.91%,且其结构简单、外形轻薄,有望实现与普通建筑的有效结合。     

基于天空辐射冷却系统的光伏组件降温研究

在南北向相邻两排光伏组件之间,背阳设置天空辐射冷却模块,不仅可有效利用屋顶面积,还可提升辐射冷却性能。辐射冷却模块产生的冷量通过水系统作用于光伏组件背面的换热模块,对光伏组件进行降温,提升光伏发电效率,延长使用寿命。实验结果表明：该系统在夏季和秋季可分别使光伏组件日平均温度降低13.6℃和10.6℃,发电效率可分别提升1.21%和0.96%。     

光伏/光热-地源热泵联合供热系统运行性能研究

为解决太阳电池的发电效率随温度升高而下降以及地源热泵系统供热引起的土壤热失衡问题,以典型居住建筑的光伏/光热-地源热泵（PV/T-GSHP）联合供热系统为研究对象,基于TRNSYS软件,采用土壤温度、地源热泵机组季节能效比、光伏发电效率和太阳能保证率为评价指标,对该联合供热系统进行运行性能分析。研究结果表明：夏热冬冷地区（以长沙为例）太阳能保证率相对较高,PV/T组件面积为满屋顶最大化安装（900 m²）时,第20年末土壤温度相比初始地温仅升高0.8 ℃,热泵机组季节能效比约为5.1,太阳能保证率为97.0%~98.7%;不同气候地区的太阳能保证率与PV/T组件面积和建筑全年累计供热量有关,通过定义单位建筑全年累计供热量PV/T组件面积指标,得到中国不同气候地区的太阳能保证率与该指标的耦合关系,回归方程的决定系数R²为0.983,得出在已知建筑全年累计供热量和太阳保证率设计目标值的条件下所需PV/T组件面积的计算方法。PV/T-GSHP联合供热系统的全年运行能耗显著小于平板太阳能集热器-地源热泵联合系统（最小降幅为沈阳,49.7%）,远小于空气源热泵（最小降幅为石家庄,79.8%）和燃气壁挂炉（最小降幅为沈阳,65.1%）。     

某15MW太阳能屋顶光伏发电工程的应用分析

在对太阳能屋顶光伏发电系统构成及发展意义阐述的基础上,通过对某15MW屋顶光伏发电工程大量实际数据的分析,表明太阳能屋顶光伏发电工程具有良好的社会、经济效益和广阔的发展前景。     

PV building lements

The LESO-PB has been working on the architectural integration of photovoltaic elements with the financial support of the Swiss Federal Office of Energy since 1990. In this paper, we discuss the advantages and the feasibility of the integration of photovoltaics, focusing on the following test-installations:— The DEMOSITE, an international exhibition centre of photovoltaic building elements, which was set up to inform potential users (architects, authorities and anybody who might commission a building) about the architectural integration possibilities of photovoltaics.— Two new photovoltaic systems integrated into buildings on the campus of the Swiss Federal Institute of Technology: (1) cladding on the facade of one of the buildings of the Department of Electricity, and (2) an innovative flat roof installation situated on the building of the Department of Materials where photovoltaic panels are mounted on low supports of reinforced concrete.     

Photovoltaic collectors efficiency according to their integration in buildings

A model for building integrated photovoltaic systems has been developed and implemented in a dynamic simulation tool. This tool takes into account the thermal interactions between the PV collector and the building. The influence of the type of integration upon the PV collector efficiency has been evaluated and hybrid PV/air collectors have been studied. An overall efficiency is defined, including the production of electricity and heat. A case study has been performed on two different typical buildings. In the case of a multi-crystalline silicon PV collector integrated on the roof of a single family house located in Paris, the efficiency of unventilated PV modules fixed on the roof is 14%. If the PV collector is used to preheat the ventilation air, the efficiency reaches 20%. A proper building integration also improves the environmental balance of PV technologies over their life cycle.     

Field thermal performance of naturally ventilated solar roof with PCM heat sink

For decades, residential and commercial roofs have been considered a prime location for installation of building integrated solar systems. In climatic conditions of East Tennessee, USA, an experimental solar roof was tested during 2009/2010, by a research team representing Metal Construction Association (MCA), and a consortium of building insulation companies, photovoltaic (PV) manufacturers, and energy research centers. The main objective was to thermally evaluate a new roofing technology utilizing amorphous silicon PV laminates integrated with the metal roof panels. In order to mitigate thermal bridging and reduce roof-generated thermal loads, this novel roof/attic assembly contained a phase change material (PCM) heat sink, a ventilated air cavity over the roof deck, and thermal insulation with an integrated reflective surface. During winter, the experimental roof was expected to work as a passive solar collector storing solar heat absorbed during the day, and increasing overall attic air temperature during the night. During summer, the PCM was expected to act as a heat sink, reducing the heat gained by the attic and consequently, lowering the building cooling-loads.In this paper, field thermal performance data of the experimental PV-PCM roof/attic system are presented and discussed. Performance of the PV-PCM roof/attic is evaluated by comparing it to a control asphalt shingle roof. The test results showed about 30% heating and 50% cooling load reductions are possible with the experimental roof configuration.     

A prototype photovoltaic/thermal system integrated with transpired collector

Building-integrated photovoltaic/thermal (BIPV/T) systems may be utilized to produce useful heat while simultaneously generating electricity from the same building envelope surface. A well known highly efficient collector is the open-loop unglazed transpired collector (UTC) which consists of dark porous cladding through which outdoor air is drawn and heated by absorbed solar radiation. Commercially available photovoltaic systems typically produce electricity with efficiencies up to about 18%. Thus, it is beneficial to obtain much of the normally wasted heat from the systems, possibly by combining UTC with photovoltaics. Combination of BIPV/T and UTC systems for building facades is considered in this paper - specifically, the design of a prototype façade-integrated photovoltaic/thermal system with transpired collector (BIPV/T). A full scale prototype is constructed with 70% of UTC area covered with PV modules specially designed to enhance heat recovery and compared to a UTC of the same area under outdoor sunny conditions with low wind. The orientation of the corrugations in the UTC is horizontal and the black-framed modules are attached so as to facilitate flow into the UTC plenum. While the overall combined thermal efficiency of the UTC is higher than that of the BIPV/T system, the value of the generated energy - assuming that electricity is at least four times more valuable than heat - is between 7% and 17% higher. Also, the electricity is always useful while the heat is usually utilized only in the heating season. The BIPV/T concept is applied to a full scale office building demonstration project in Montreal, Canada. The ratio of photovoltaic area coverage of the UTC may be selected based on the fresh air heating needs of the building, the value of the electricity generated and the available building surfaces.