Research On PV Energy Potential Of Rooftop In Urban Area

Solar energy utilization is an important measure for energy crisis solving,climate change mitigation,and urban sustainable development implement.The building-integrated photovoltaic(BIPV)technology is mature enough for large-scale applications in urban environment,thus assessing rooftop photovoltaic(PV)potential of in urban area is the essential part in urban solar energy utilization planning.Combined with urban planning index,studied on building rooftops PV utilization potential from aspects of urban planning,which may provide theoretical basis and practical guidance for large-scale application of PV systems and rational target setting of distributed PV power generation.Research contents are successively as follows:(1)Problems exploration.Described related theory of BIPV,levels of PV energy potential assessment,and solar energy resources assessment;recalled large-scale application of solar energy PV technology,exploration of PV energy potential improvement on building surface in urban planning and design process,and development status of quantitative evaluation of PV potential in built up area.Those provided basic information for later study in the paper.(2)Analysis and extraction.Analyzed on the complexity of urban building rooftops composition and solar environment,refined three levels influential factors of building rooftop PV utilization;proposed evaluation theory of building rooftops PV utilization potential specific to urban detailed regulatory plan phase in our country;set up evaluation index that “met standards of three hours sunshine duration on winter solstice ”-“RPVID” as rooftops PV installation condition.On that basis,we proposed specific assessment methods and procedures,which provided principles for the following research.(3)Solutions.Employed utilization coefficient method to study on calculation method of urban building rooftops PV utilization available area: including calculation method of rooftops total area according to regulatory detailed planning index,calculation formula and data range of rooftops PV available coefficient determination by three levels reduction factor determination of street space,building layout and individual building,and so on.Studied on calculation methods of PV module surface radiation and effective area as well as prediction of PV system power generation,and so on.(4)Empirical conclusions.For Tianjin urban central area,based on the solar energy resource status and urban detailed regulatory plan indicator in Tianjin,using GIS analysis method,calculated possible building rooftops solar PV utilization potential of existing and future building.Innovative research results of this paper included: proposed assessment theory of building rooftops PV utilization potential combined with urban detailed regulatory plan,set up index of “Rooftop Photovoltaic Installation Density(RPVID)”,and determined calculation formula and data range of rooftops PV available coefficient.Significances of these results are to evaluate PV utilization potential distribution of existing and future building rooftops in urban area;to guide and improve solar energy PV utilization planning in urban planning process;to raise awareness of architects and urban planners to consider building solar energy PV utilization early in the design process,thus to further improve urban building PV utilization potential.