Progress of semitransparent emerging photovoltaics for building integrated applications

With the rapid development of emerging photovoltaics technology in recent years,the application of building-integrated photovoltaics(BIPVs)has attracted the research interest of photovoltaic communities.To meet the practical application requirements of BIPVs,in addition to the evaluation indicator of power conversion efficiency(PCE),other key performance indicators such as heat-insulating ability,average visible light transmittance(AVT),color properties,and integrability are equally important.The traditional Si-based photovoltaic technology is typically limited by its opaque properties for application scenarios where transparency is required.The emerging PV technologies,such as organic and perovskite photovoltaics are promising candidates for BIPV applications,owing to their advantages such as high PCE,high AVT,and tunable properties.At present,the PCE of semitransparent perovskite solar cells(ST-PSCs)has attained 14%with AVT of 22–25%;for semitransparent organic solar cells(ST-OSCs),the PCE reached 13%with AVT of almost 40%.In this review article,we summarize recent advances in material selection,optical engineering,and device architecture design for high-performance semitransparent emerging PV devices,and discuss the application of optical modeling,as well as the challenges of commercializing these semitransparent solar cells for building-integrated applications.

Building Integrated Photovoltaic Systems for Single Family Dwellings: Innovation Concepts

Growing consumer interest in distributed Building Integrated Photovoltaic (BIPV) Systems and industry competition to reduce installation costs are stimulating the development of deploying these materials to the residential sector of the building industry. This emerging market continues to attract the attention of many stakeholders, yet cohesive opportunities to deploy in residential sectors, specifically detached single-family dwellings, is scattered. As a result, this study of literature and implementation strategies through simple examples looks to identify several characteristics related to BIPV. Characteristics that were studied in this initial pilot study were design considerations for system selection, applicability to residential construction, and system and material options and enhancements. A case-study home was analyzed demonstrating opportunity for implementation of BIPV on an existing residence. Strategies for maximizing the energy-generating capacity of the system to achieve net-zero energy performance, including all building surfaces and landscaping were also explored. This body of work provides a state-of-the-art review on common materials as well as the more customizable types.

Research on Key Technologies of Solar Photovoltaic Building Integration

On December 21,2020,The State Council Information Office issued a white paper titled"China's Energy Development in the New Era,"in which the installed capacity of hydropower,wind power,photovoltaic power and biomass power generation in China ranked first in the world[1].Solar photovoltaic power generation is the most important development direction of clean energy in the world.It is an important energy strategy to combine it with the field of construction in China.This paper mainly introduces the characteristics and problems of the key technologies of solar photovoltaic building integration,and explores its future development direction and ways,in order to constantly promote the industrialization of new energy technology in China.

A New Dynamic and Vertical Photovoltaic Integrated Building Envelope for High-Rise Glaze-Facade Buildings

Substantially glazed facades are extensively used in contemporary high-rise buildings to achieve attractive architectural aesthetics.Inherent conflicts exist among architectural aesthetics,building energy consumption,and solar energy harvesting for glazed facades.In this study,we addressed these conflicts by introducing a new dynamic and vertical photovoltaic integrated building envelope(dvPVBE)that offers extraordinary flexibility with weather-responsive slat angles and blind positions,superior architectural aesthetics,and notable energy-saving potential.Three hierarchical control strategies were proposed for different scenarios of the dvPVBE:power generation priority(PGP),natural daylight priority(NDP),and energy-saving priority(ESP).Moreover,the PGP and ESP strategies were further analyzed in the simulation of a dvPVBE.An office room integrated with a dvPVBE was modeled using EnergyPlus.The influence of the dvPVBE in improving the building energy efficiency and corresponding optimal slat angles was investigated under the PGP and ESP control strategies.The results indicate that the application of dvPVBEs in Beijing can provide up to 131%of the annual energy demand of office rooms and significantly increase the annual net energy output by at least 226%compared with static photovoltaic(PV)blinds.The concept of this novel dvPVBE offers a viable approach by which the thermal load,daylight penetration,and energy generation can be effectively regulated.

Design and performance testing of a novel building integrated photovoltaic thermal roofing panel

A novel building integrated photovoltaic thermal(BIPVT)roofing panel has been designed considering both solar energy harvesting efficiency and thermal performance.The thermal system reduces the operating temperature of the cells by means of a hydronic loop integrated into the backside of the panel,thus resulting in maintaining the efficiency of the solar panels at their feasible peak while also harvesting the generated heat for use in the building.The performance of the proposed system has been evaluated using physical experiments by conducting case studies to investigate the energy harvesting efficiency,thermal performance of the panel,and temperature differences of inlet/outlet working liquid with various liquid flow rates.The physical experiments have been simulated by coupling the finite element method(FEM)and finite volume method(FVM)for heat and mass transfer in the operation.Results show that the thermal system successfully reduced the surface temperature of the solar module from 88℃to as low as 55℃.Accordingly,the output power that has been decreased from 14.89 W to 10.69 W can be restored by 30.2%to achieve 13.92 W.On the other hand,the outlet water from this hydronic system reaches 45.4℃which can be used to partially heat domestic water use.Overall,this system provides a versatile framework for the design and optimization of the BIPVT systems.

Comprehensive energy, economic, environmental assessment of a building integrated photovoltaic-thermoelectric system with battery storage for net zero energy building

To realize the goal of net zero energy building(NZEB),the integration of renewable energy and novel design of buildings is needed.The paths of energy demand reduction and additional energy supply with renewables are separated.In this study,those two are merged into one integration.The concept is based on the combination of photovoltaic,thermoelectric modules,energy storage and control algorithms.Five types of building envelope systems,namely PV+TE(S1),Grid+TE(S2),PV+Grid+TE(S3),PV+Battery+TE(S4)and PV+Grid+Battery+TE(S5)are studied,from aspects of energy,economic and environmental(E3)performance.The new envelope systems can achieve thermal load reduction while providing additional cooling/heating supply,which can promote advance of NZEBs.It is found that there is a typical optimum setting of thermal energy load for each one of them with minimum annual power consumption.Except for the S1 system,the rest can realize negative accumulated power consumption in a year-round operation,which means the thermal load of building envelope could be zero.The uniform annual cost for S1 to S5 under interest rate of 0.04 are 19.78,14.77,23.83,60.53,64.94$/m2,respectively.The S5 system has the highest environmental effect with 3.04 t/m2 reduction of CO_(2) over 30 years of operation.

Adoption of wide-bandgap microcrystalline silicon oxide and dual buffers for semitransparent solar cells in building-integrated photovoltaic window system

We focused on developing penetration-type semitransparent thin-film solar cells(STSCs) using hydrogenated amorphous Si(a-Si:H) for a building-integrated photovoltaic(BIPV) window system. Instead of conventional p-type a-Si:H, p-type hydrogenated microcrystalline Si oxide(p-μc-SiOx:H) was introduced for a wide-bandgap and conductive window layer. For these purposes, we tuned the CO2/SiH4 flow ratio(R) during p-μc-SiOx:H deposition. The film crystallinity decreased from 50% to 13% as R increased from 0.2 to 1.2. At the optimized R of 0.6, the quantum efficiency was improved under short wavelengths by the suppression of p-type layer parasitic absorption. The series resistance was well controlled to avoid fill factor loss at R = 0.6. Furthermore, we introduced dual buffers comprising p-a-SiOx:H/i-a-Si:H at the p/i interface to alleviate interfacial energy-band mismatch. The a-Si:H STSCs with the suggested window and dual buffers showed improvements in transmittance and efficiency from 22.9% to 29.3% and from 4.62% to 6.41%, respectively, compared to the STSC using a pristine p-a-Si:H window.

A maximum power point tracking strategy applied to building integrated photovoltaics

To solve the problem of permanent-shadow shading of photovoltaic buildings,a maximum power point tracking(MPPT)strategy to determine the search range by pre-delimiting area is proposed to improve MPPT efficiency.The single correspondence between the solar-cell current-voltage(I-V)curve and the illumination conditions was proved by using the single-diode model of photovoltaic cells,thus proving that a change in the illumination conditions corresponds to a unique maximum power point(MPP)search area.According to the approximate relationship between MPP voltage,current and open-circuit voltage and short-circuit current of a photovoltaic module,the voltage region where the MPP is located is determined and the global maximum power point is determined using the power operating triangle strategy in this region.Simulation carried out in MATLAB proves the correctness and feasibility of the theoretical research.Simulation results show that the MPPT strategy proposed in this paper can improve the average efficiency by 1.125%when applied in series as building integrated photovoltaics.

冰上运动建筑曲面光伏参数化集成设计研究

2022年冬奥会成功举办,国内掀起了冰上体育运动的热潮,冰上运动建筑需求量和能源消耗量随之增长。光伏建筑一体化(Building Integrated Photovoltaic,BIPV)作为建筑节能的主要手段之一,在体育建筑屋面具有较大的集成潜力。通过建立寒冷地区曲面冰上运动建筑典型模型进行集成设计研究,基于Grasshopper参数化平台实现新型柔性CIGS薄膜光伏组件沿屋面曲线形态的优化布置,从两个层级出发,提出参数化设计方法与构造措施。通过Honeybee进行能耗模拟,结果表明,该柔性光伏系统全年可以为冰上运动建筑降低15.82%的能量消耗,进而验证了该方案的节能性,为建筑师进行寒冷地区曲面冰上运动建筑设计的节能优化设计提供数据支撑及科学依据。

绿色金融支持我国东部地区BIPV建筑发展评价及耦合分析

以我国东部地区的10个省(市)为例,建立2017-2021年绿色金融和光伏建筑一体化(BIPV)发展的评价指标体系,并利用熵值法与耦合协调度模型开展实证分析。研究结果表明:从区域性发展差异上看,绿色金融发展和BIPV建筑发展水平较高的是上海市和北京市,相对落后的是河北省和海南省;从发展态势上看,绿色金融和BIPV建筑发展总体上呈上升趋势;从耦合特征上看,近年来我国东部地区绿色金融和BIPV建筑发展两系统之间的耦合度及耦合协调度均较高,且总体呈逐步增长的趋势。

光伏光热一体化建筑热负荷能效分层调度仿真

光伏光热一体化系统中涉及多种能源,包括太阳能和热能等。由于不同能源的产生、存储和使用特性不同,加之系统内部的复杂性,使得实现多能源协同调度变得复杂。为了获取满意的建筑热负荷能效分层协同调度结果,提出一种光伏光热一体化建筑热负荷能效分层协同调度方法。研究光伏光热一体化建筑中热负荷的热量传递过程,对热负荷自身和热惯性展开分析,获取热负荷热惯性大小和室内热量需求两者的关系。以最大[火用]效率和最小调度成本为目标,分别建立光伏光热一体化建筑热负荷能效上层和下层协同调度模型。通过量子粒子群算法对模型展开分析计算,确定最优建筑热负荷能效分层协同调度方案。实验分析表明,所提方法的热负荷能效分层协同调度效果好,且节能效益高。

光伏建筑一体化光伏幕墙体系与经济性研究

在当今全球能源转型的大背景下,建筑行业作为主要能源消费领域,其能源消费模式的革新对于实现国家层面的可持续发展目标至关重要。鉴于此,显著削减建筑领域对化石燃料的依赖,并积极拓宽可再生能源的利用渠道,成为了推动绿色建筑革命的重要策略。光伏建筑一体化(BIPV)技术,作为一种将高效光伏发电系统与现代化建筑设计、建造工艺深度融合的创新实践,不仅展现了太阳能这一清洁、可再生资源的巨大应用潜力,而且也预示着未来建筑领域在能源自给自足方面广阔的发展蓝图。为了探究光伏建筑一体化的现状,文章对光伏建筑一体化的背景及常用的应用场景进行研究,通过案例分析光伏幕墙增量成本,并采用静态投资回收期和效益费用比两个参数对薄膜类光伏幕墙、晶硅类光伏幕墙、薄膜类光伏采光顶三种光伏方案的经济性进行分析,为后续光伏建筑一体化中光伏幕墙的经济性提供参考。

外显、灵活、多维、高效——从2022中国国际太阳能十项全能竞赛看建筑与光伏一体化设计趋势

建筑光伏一体化技术是实现建筑行业节能减碳的重要途径。以第三届中国国际太阳能十项全能竞赛(SDC2022)为例,对15个参赛作品在建筑与光伏一体化设计上的特征进行了比较,从美学表现、构造整合、功能复合、性能提升4个维度分析了当前建筑与光伏一体化的设计新趋势,指出:在美学表现上,通过光伏组件材质外观和光伏方阵形成积极外显的形态;在构造上,采用不同类型光伏灵活组合衍生多种应用场景;在功能上,将光伏发电与建筑围护结构的采光、集热、遮阳、防护等功能进行多维度复合;在性能上,通过光伏朝向与倾角、散热设计和电气系统综合提升产能效率。为建筑与光伏一体化技术的推广和应用提供新思路。

基于IPSO-BPNN的楼宇屋顶光伏出力功率超短期预测

在建筑光伏一体化技术的背景下,准确预测屋顶光伏输出功率对于优化建筑能源管理和确保光伏电力的稳定并网至关重要。提出了一种基于IPSO-BPNN的楼宇屋顶光伏出力功率超短期预测模型,该模型引入Sine混沌序列初始化和精英粒子反向学习策略,改进了基本的PSO算法,并利用此算法对基本BPNN模型的超参数进行优化,从而实现了对屋顶光伏出力功率更加准确的预测。预测模型性能测试实验表明,所提出的IPSO-BPNN预测模型在不同季节的预测准确性和稳定性都有显著提高。该模型能够准确预测屋顶光伏发电功率,为建筑光伏一体化系统的稳定运行和能源管理提供切实可行的解决方案。

神经网络驱动的建筑自适应表皮产出性能预测方法

作为应对环境与能源问题的解决办法,耦合动态光伏遮阳与建筑表皮种植的建筑自适应表皮(Adaptive Facade)为城市可持续性提供了新机会,但如何快速准确预测电能与作物产出是设计前期关键问题之一。为解决此问题,以城市居住建筑为例,提出基于机器学习神经网络模型的产出性能预测方法,以替代传统光伏软件模拟与作物产出估算方法。首先建立由实测数据训练并进行差异性激活函数对比择优的机器学习神经网络预测模型,进而搭建交互界面预测平台。结果显示,与基础案例相比,建筑自适应表皮显著提高室内热舒适时间比,降低室内眩光,且满足家庭年用电需求9.3%~10.9%(新加坡)、8.4%~9.8%(海口)以及家庭全年蔬菜需求32%(新加坡)、27.6%(海口),该预测方法展现了预测过程的便捷性与预测结果的可靠性,推动了建筑自适应表皮在可持续城市人居环境建设领域的应用。

从BIPV(光伏建筑一体化)到BIPVES(光伏储能建筑一体化)

[目的]随着光伏、储能、新型建材及装配式建筑产业的发展,将光伏组件与屋面、墙体、遮阳等构件进行一体化设计与制造的光伏建筑一体化(Building Integrated Photovoltaic,BIPV)技术开始延伸为光伏储能建筑一体化(Building Integrated Photovoltaic and Energy Storge,BIPVES)技术。[方法]文章提出世界首个可充电水泥电池,将建筑墙体与光伏发电装置、储放电装置相融合;对设备和材料进行跨界创新,在玻璃表面打印高清晰度、高透光率花纹图案,制造高效光伏建材;研发预制式储能墙体,与各类钢结构装配式建筑体系进行结合,实现订制式生产、装配式施工,形成建筑构件与光伏、储能一体化的变革趋势。[结果]水泥基电池实现了建筑墙体具有光伏发电、储电以及供电等多种功能;新一代光伏建材可节省建筑外立面装饰材料的成本,降低建筑物碳排放;光伏和储能等可再生能源技术在建筑中的一体化集成,可取得最大化收益。[结论]新型光伏建材技术和水泥电池等新型储能技术具有发展前景,将可充电电池构件、光伏外墙板与装配式建筑墙体及预埋件进行组合集成并推广应用具有可行性。

基于试验测试的光伏阵列建模与发电量估算

本文以建筑光伏一体化系统作为研究对象,计及光伏板受内部材料和温度、光照等外部条件对其输出电压和电流的影响,建立光伏板的准确数学模型;并基于实际光伏板的测试性能,着重研究光伏阵列的串并联计算、光伏阵列的建模和发电量估算三个关键问题。通过数值仿真验证方法的正确性和有效性。

光伏储能系统在零能耗建筑的应用

本文从零能耗建筑角度出发,以北京地区为例,在结合实际项目用能情况的基础上,通过不同光伏组件种类、发电特性对比进行太阳能光伏组件选型分析与系统设计。结合储能装置应用属性,分析得出光伏储能系统的最佳配置方式与充、放电控制逻辑,并通过实际运行数据验证光伏储能系统在零能耗建筑应用的可行性。在提高光伏发电的自我消纳能力、光伏储能系统应用的协调性和灵活性,以及提升经济效益等方面提供了良好的案例实践,证明了光伏储能系统在华北地区有广泛的应用场景。

用于光伏玻璃幕墙的聚光系统设计与研究

为了能同时满足光伏玻璃幕墙的采光和建筑发电需求,设计了一种由双抛物线结构和导光板组成的混合式聚光器。主要介绍了聚光器的构成,并对其性能进行了初步的测量分析。这种新型的聚光器的几何聚光比为6,系统效率在90%,通过比较不同单元模块宽度的聚光器和不同移动距离的聚光器模型,测量了变量与入射偏角的曲线,得到聚光器的接收范围为±3°。在垂直入射条件下,聚光系统的光伏模块效率可以达到70%,减少室内的眩光。最后使用DIALUX软件对新型系统采光进行了辐照度分析,全天辐照度超过300 lx,照度均匀度达到了0.956。结果表明聚光系统用于光伏玻璃幕墙是可行的,可以提高使用舒适度,也降低了建筑成本,该系统的实用性可以替代传统中空玻璃。