Observations of Snow and Ice Formation on Solar Photovoltaic Panels and an Enhanced Method of Modelling Snow Melting from Solar Photovoltaic Panels

• Author / Creator

  Robert Elliott Pawluk

• One of the fundamental limitations of solar photovoltaic (PV) generating systems in cold regions is snow accumulations blocking irradiance from reaching the PV cells. Snow accumulations on PV panels result in both reduced electricity generation and increased uncertainty in electricity generation predictions. A comprehensive literature review summarizes existing research that is targeted at quantifying and modelling the impact of snow on the electricity generation of PV systems. Furthermore, it analyses factors that influence the effect snow has on PV panels and mitigation methods to reduce the effect of snow. In order to better understand the formation of snow accumulations and improve the prediction of snow clearing on PV panels, an experiment was set up in Edmonton, Canada. The experimental setup gathered data that served as the foundation for the remaining analyses in the thesis. Observations of the formation of ice between the snow accumulations and the panel surface are presented, and analysis identifies the sources of moisture for icing: snow melting on contact with a warm panel, ice pre-existing on the panel before the snow accumulation formed, and partial melting of the existing snow accumulation. The formation of ice provided evidence that adhesion between the panel, ice, and snow acts together with friction to prevent snow accumulations from sliding clear of PV panels. An enhanced empirical model is presented to predict the meteorological conditions under which snow accumulations will likely begin sliding or melting from PV panels. The key enhancement is using an estimation of the radiation being absorbed by the panel rather than the plane-of-array irradiance on a snow-covered panel. This empirical model is evaluated using data collected iii through experimentation. The proposed changes increase the modelling precision by up to a factor of four. Lastly, a simple first-principle model to predict PV panel temperature is established. The model is a transient state model and accounts for the heat capacity of the PV panels. The model was employed to further enhance the developed empirical threshold models by accounting for the heat capacity of the panels. The heat capacity was accounted for in the threshold by using time dependent-weighted values of the current and preceding irradiance, for which the weighting coefficients were determined with the first principle model.

• Subjects / Keywords

  • mitigation
  • Solar
  • renewable energy
  • snow
  • photovoltaic
  • ice
  • model

• Graduation date

  Spring 2019

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/r3-1hgj-gw06

• License

  Permission is hereby granted to the University of Alberta Libraries to reproduce single copies of this thesis and to lend or sell such copies for private, scholarly or scientific research purposes only. Where the thesis is converted to, or otherwise made available in digital form, the University of Alberta will advise potential users of the thesis of these terms. The author reserves all other publication and other rights in association with the copyright in the thesis and, except as herein before provided, neither the thesis nor any substantial portion thereof may be printed or otherwise reproduced in any material form whatsoever without the author's prior written permission.