Thermal Pyranometer Using the Open Hardware Arduino Platform

Abstract

Thermal Pyranometers are very important devices for evaluating the intensity of solar radiation under different climatic conditions. These devices utilize thermal radiation for comparison and determination of their efficiency. Because of this wide use associated with the development of new technologies, a simple and low-cost version of thermal pyranometer has been studied, designed and manufactured. A blackened aluminum disk is used as a hot junction, and the cold junction is exposed to ambient air. The two terminals are connected to a digital amplifier with output signal directed to an Arduino board. A device calibration was performed by comparing the results with a commercial photodiode sensor. Statistical analysis of the calibration data considering a 99% confidence level leads to an estimated standard error of 20.8 W/m². An analysis of its response time also estimated from a dynamic model. This model uses a numerical solution of the energy balance on heat exchange between the aluminum disc and the environment. The instrument response time based on the average of the estimates obtained from the dynamic model is about 1.5 minutes. Based on these studies it was concluded that the characteristics of the sensor are adequate for most solar energy tests and the final cost of US $ 60.00 is much lower than the large majority of such commercial devices.

Keywords

• Pyranometer; Radiometer; Thermal sensor; Arduino

References

1. [1] I. Zanesco and A. Krezinger, “On the threshold of the accuracy of using silicon solar cells to measure global solar irradiance,” in 11th Photovoltaic energy conference, Montreux Swizerland, Montreux - Suíça, 1992.[2] S. Awasthi, A. Dubey, J. M. Kellar, and O. Mor, “Design and simulation of eletronic instruments for solar energy measurement system,” Int. J. Sci. & Eng. Res., 3, 1, Jan-2012.[3] H. Vera Luiz, A. J. Busso, and F. Benitez, “Piranómetro fotovoltaico con sistem autónomo de adquisición de datos,” Avances en Energías Renovables y Medio Ambiente, 9, 2005.[4] I. Zanesco, “Analise e Construçao de um Piranômetro Fotovoltaico,” Dissertação de Mestrado, Universidade Federal do Rio Grande do Sul, Porto Alegre, 1991.[5] M. A. Martínez, J. M. Andújar, and J. M. Enrique, “A new inexpensive pyranometer for the visible spectral range,” Sensors, 9, 4615–4634, 2009.[6] D. W. Medugu, F. W. Burari, and A. A. Abdulazeez, “Construction of a reliable model pyranometer for irradiance measurements,” African Journal of Biotechnology, 9, 1719–1725, 2010.[7] ISO 9847, Solar Energy — Calibration of field pyranometer by comparison to a reference pyranometer. 2013.[8] ISO 9060, Standard & Pyranometer Measurement Accuracy. 2012.[9] W. A. Vilela, “Estudo, desenvolvimento e caracterização de radiômetros para medição da raciação solar,” Tese de Doutorado, Instituto Nacional de Pesquisas Espaciais - INPE, São José dos Campos - SP, 2010.[10] WMM, “Instruments and observing methodos - Report No 98.” World Meteorological Organization, 2009.[11] M. et al Krazenerg, “Rastreabilidade de radiômetros para medida da energia solar,” in Meteorologia 2003 - Meteorologia para a vida, Recife - PE, 2006.[12] M. A. M. Bohórquez, J. M. E. Gómez, E. D. Aranda, M. J. V. Vázquez, and J. M. A. Márquez, “Sistema de instrumentación de bajo coste para la medición de irradiancia en el rango espectral visible,” in XXXII Jornadas de Automática, Sevilla - Espanha, 1, 2011. 1.[13] S. N. Nwankowo, M. N. Nnabuchi, and J. E. Ekpe, “Construction and characterization of a pyranometer using locally avaliable materials for global solar radiation measurement,” Asian Transactions on Basic and Applied Sciences, 2, 2012.[14] J. L. Souza and J. F. Escobedo, “Construção de um saldo radiômetro com termopilha de filme fino e avaliação de sua performance,” Revista Brasileira de Meteorologia, 10, 29–36, 1995.[15] J. F. Escobedo, V. A. Frisina, R. P. Ricieri, and A. P. Oliveira, “Radiômetros solares com termopilhas de filmes finos - I Descrição e custos,” Revista Brasileira de Aplicações de Vácuo, 16,, 1997.[16] J. M. Gomes, P. M. Ferreira, and A. E. Ruano, “Implementation of an intelligent sensor for measurement and prediction of solar radiation and atmospheric temperature,” in Sensors Journal, IEEE, Floriana - Malta, 2011, 1–6.[17] E. Avallone, “Avaliação da Eficiência Térmica de um Coletor Solar Tipo Tubo Evacuado Modificado,” Master Thesis, Universidade Estadual Paulista - Júlio de Mesquita Filho, Campus de Bauru, 2013.[18] J. A. Duffie and W. A. Beckman, Solar Engineering of Thermal Process, 4a., vol. 1. USA: John Wiley & Sons, 2013.[19] S. A. Kalogirou, “Solar thermal collectors and applications,” Progress in Energy and Combustion Science, 30, 231–295, 2004.[20] S. A. Kalogirou, Solar Energy Engineering, 1a., vol. 1. United States of America: British Library Cataloguing-in-Publication, 2009.[21] P. Berdahl and M. Martin, “Emissivity of clear skies,” Solar Energy, vol. 32, no. 5, p. 663, 1984.[22] K. G. T. Hollands, T. E. Unny, G. D. Raitby, and L. Konieck, “Free convection heat transfer across inclined air layers,” Trans ASME J. Heat Transfer, 98, 1976.[23] F. P. Incropera, D. P. Dewit, T. I. Bergman, and A. S. Lavine, Fundamentos de transferência de calor e massa, 6th ed., vol. 1, 1 vols. Rio de Janeiro: LTC - Livros técnicos e científicos Editora Ltda, 2008.[24] V. L. Scalon and S. D. R. Oliveira, “Theoretical analysis of a flat pyranometer,” presented at the VII SiAT - Simpósio de Análise Térmica, Universidade Estadual Paulista “Júlio de Mesquita Filho,” 4, 2015.