Prof.  Emanuele  Calabrò
Technological Technical Institute of Messina (Italy),  Italy

Title: The problem of periodically changing the slope of fixed solar panels to acquire maximum solar energy

Abstract:

In the recent years renewable energy technology has largely developed by the installation of photovoltaic systems that generate power without emitting pollutants and requiring no fuel.
To this aim, the most used technic is represented by fixed solar panels installed in the top of buildings. Nevertheless, the problem to be solved is the optimum inclination of solar panels in order to acquire the maximum solar energy. Indeed, solar radiation varies with geographic latitude, season, and time of day due to the various sun positions in the sky.
Hence, the problem of designing the optimal tilt angle and the orientation of a solar panel arises for maximizing solar radiation collection at a fixed latitude. Several algorithms to solve this problem have been provided up to now [1-19]. In particular, a mathematical modeling based on the maximization of the theoretical expression of the global solar irradiation impinging on an inclined surface, with respect to the slope and orientation of the panel and to the solar hour angle was recently proposed [20]. In that study an algorithm to calculate the optimum tilt angle of solar panels by means of global horizontal solar radiation data due to Earth-based meteorological stations was provided by means of a set of transcendent equations, whose solutions give the optimum tilt and orientation of a solar panel. It resulted that the optimum tilt angle resulted was related to latitude by a linear regression with significant correlation coefficients. Anyway, both studies [19] and [20] highlighted significant differences among the values of annual global solar radiation acquired by a solar panel at different months, apart from the slope of the panel. In [19] the idea of planning semi-fixed solar panels, whose tilt angle can be changed twice a year, at least, was proposed, so that we can hypothesize that the tilt angle variation can be done manually. Nevertheless, the slope of solar panels should be changed every month to obtain an advantageous energy gain, as it was highlighted in [20]. Hence, the use of lighter materials for the construction of solar panels is desirable in order that an automatic periodic rotation system can be designed without onerous maintenance costs.

References
[1] B. Y. H. Liu and R. C. Jordan, Solar Energy, vol. 4, no. 3, pp. 1–19, 1960.
[2] D. G. Erbs, S. A. Klein, and J. A. Duffie, Solar Energy, vol. 28, no. 4, pp. 293–302, 1982.
[3] M. Iqbal, Solar Energy, vol. 24, no. 5, pp. 491–503, 1980.
[4] E. L. Maxwell, Tech. Rep. SERI/TR-215-3087, Solar Energy Institute, Golden, USA, 1987.
[5] R. R. Perez, P. Ineichen, E. L. Maxwell, et al. Proceedings of ISES Solar World Congress, pp. 951–956, Denver, Colo, USA, 1992.
[6] G. Qiu and S. B. Riffat, International Journal of Ambient Energy, vol. 24, pp. 13–20, 2003.
[7] J. I. Yellott, ASHRAE Journal, vol. 15, no. 12, pp. 31–42, 1973.
[8] G. Lewis, Solar and Wind Technology, vol. 4, no. 3, pp. 407–410, 1987.
[9] S. A. Klein, Solar Energy, vol. 19, no. 4, pp. 325–329, 1977.
[10] R. Perez, P. Ineichen, R. Seals, et al. Solar Energy, vol. 44, no. 5, pp. 271–289, 1990.
[11] L. Robledo and A. Soler, Energy, vol. 23,no. 3, pp. 193–201, 1998.
[12] F. J. Olmo, J. Vida, I. Foyo, et al. Energy, vol. 24, no. 8, pp.689–704, 1999.
[13] J. K. Page, Department of Building Science, University of Sheffield, Sheffield, UK, 1977.
[14] J. A. Duffie and W. A. Beckman, Solar Engineering of Thermal Process, JohnWiley & Sons, New York, NY, USA, 1991.
[15] J. LeQuere, Tech. Rep. CSTB TEAS 87, CSTB, Paris, France, 1980.
[16] J. E. Hay and J. A. Davies, Proceedings of the 1st Canadian Solar Radiation Data Workshop, J. E. Hay and T. K. Won, Eds., pp. 59–72, Toronto, Canada, 1980.
[17] T. M. Klucher, Solar Energy, vol. 23, no. 2, pp. 111–114, 1979.
[18] R. Perez, R. Seals, P. Ineichen, et al. Solar Energy, vol. 39, no. 3, pp. 221–231, 1987.
[19] E. Calabrò, Journal of Renewable and Sustainable Energy, vol. 1, Article ID 033104, 2009.
[20] E. Calabrò, Journal of Renewable Energy, Vol. 2013, Article ID 307547, 2013.

Biography:

Prof. Emanuele Calabrò studied physics at the University of Messina (Italy) where he obtained a Bachelor degree in Physics in 1990. Afterwards he obtained also a Bachelor  degree in  Civil Engineering, several post-graduate masters in various scientific topics and a PhD in the field of Applied Physics.

Emanuele Calabrò is Full Professor of Physics at the Technological Technical Institute of Messina (Italy). He have received the National Qualification as University Professor in Applied Physics and in Experimental Physics of Matter. Also, he was awarded with the International Prize for Excellence in Research by the Academic Brand Awards-2018. He is an expert collaborator at the Department of Mathematics and Informatics Sciences, Physics Sciences and Earth Sciences, University of Messina and he is member of the Interuniversity Consortium of Applied Physical Sciences (CISFA), Italy. He has published more than 100 refereed papers in ISI Journals, monographs and book chapters.

The fields of expertise of Prof. Emanuele Calabrò are as follows:

Study of effects of man-made electromagnetic fields on biological systems.

Resonant natural frequencies of electromagnetic fields in cancer cells.

Study of “non-resonant” frequencies in wireless communications networks.

Climatology. Solar energy. Astronomy and space sciences.