MEO shadowring method for measuring diffuse solar irradiance: Corrections based on sky cover
| Autor: | João Francisco Escobedo, Enzo Dal Pai, Georgia Codato, Jacyra Soares, Alexandre Dal Pai, Amauri Pereira de Oliveira |
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| Přispěvatelé: | Universidade Estadual Paulista (Unesp), Universidade de São Paulo (USP) |
| Rok vydání: | 2016 |
| Předmět: |
Pyranometer
Diffuse radiation Mean squared error Renewable Energy Sustainability and the Environment 020209 energy media_common.quotation_subject Irradiance 02 engineering and technology Solar irradiance RADIAÇÃO SOLAR E TERRESTRE Measuring methods Sky 0202 electrical engineering electronic engineering information engineering Anisotropy Environmental science Sky cover Shadowring Pyrheliometer Order of magnitude Remote sensing media_common |
| Zdroj: | Repositório Institucional da USP (Biblioteca Digital da Produção Intelectual) Universidade de São Paulo (USP) instacron:USP Scopus Repositório Institucional da UNESP Universidade Estadual Paulista (UNESP) instacron:UNESP |
| ISSN: | 0960-1481 |
| DOI: | 10.1016/j.renene.2016.07.026 |
| Popis: | Made available in DSpace on 2018-12-11T17:04:36Z (GMT). No. of bitstreams: 0 Previous issue date: 2016-12-01 The present paper deals with atmospheric corrections factors proposed as a function of the atmospheric transmissivity in order to correct the diffuse solar irradiance measured with the Melo-Escobedo-Oliveira Shadowring Measuring Method (MEO shadowring Method). Global irradiance was measured by an Eppley-PSP pyranometer; direct normal irradiance by an Eppley-NIP pyrheliometer fitted to a ST-3 sun tracking device and diffuse irradiance by an Eppley-PSP pyranometer fitted to a MEO shadowring. The Solar Radiometric Laboratory at Sao Paulo State University provided the measurements during the years 1996–2005. Two correction models for diffuse solar irradiance were proposed: All Sky Correction Model (ASC Model) and Sky Cover Correction Model (SCC Model). The MBE and RMSE statistical indicators performed the validations. The correction models showed results in the same order of magnitude: ASC Model showed 0.81% deviation, while SCC Model showed 0.66% deviation. Therefore, the correction models proposed as a function of the sky covering (atmospheric transmissivity) were efficient to correct the isotropic diffuse irradiance, approaching the measured and reference diffuse irradiance less than 1%. Corrections show dependence on sky coverage and seasonality. The results presented that the sky cover corrections improve the MEO shadowring method, allowing the generation of a reliable global, direct and diffuse radiation database without high financial investments. College of Agricultural Sciences / FCA / UNESP Department of Bioprocess and Biotechnology College of Agricultural Sciences / FCA / UNESP Department of Rural Engineering Institute of Astronomy Geophysics and Atmospheric Sciences USP College of Agricultural Sciences / FCA / UNESP Department of Bioprocess and Biotechnology College of Agricultural Sciences / FCA / UNESP Department of Rural Engineering |
| Databáze: | OpenAIRE |
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