Fuzzy modeling of solar irradiance on inclined surfaces

Weather Modeling and Forecasting of PV Systems Operation

“…For example, Gazela and Tambouratzis (2002) reported a model for hourly average solar radiation on tilted surface via Artificial Neural Networks. Gomez and Casanovas (2003) proposed a model for solar irradiance on arbitrarily-oriented inclined surfaces based on fuzzy logic procedures. The model considers the circumsolar and horizon zones with the geometry of the Perez et al (1987) model.…”

“…A model of estimating solar irradiance on arbitrarily oriented inclined surfaces based on hourly solar radiation average is proposed in Gomez and Casanovas (2003). Like the majority of the models for computation of solar irradiance on …”

“…(7.23) are regarded as constant for a given sky category: f = 0.122 and g = -0.063 for overcast sky, f = 0.994 and g = 0.078 for partly cloudy sky, f = 1.1363 and g = 0.358 for clear sky with high aerosol content in atmosphere and f = 1.765 and g = 0.921 for clear sky and clean atmosphere (Gomez and Casanovas 2003). The factor F b is computed by the weighted average procedure: Results of testing the fuzzy and Perez et al (1990) models against measured data on vertical surfaces in Valencia, Spain, during the years 1992-1995, are summarized in Fig.…”

“…As the author claims, the advantage of the fuzzy model is that it involves far fewer adjustable parameters and a smaller number of sky categories (while Perez et al model operates with eight sky categories, the fuzzy model needs only four). The model proposed in Gomez and Casanovas (2003), allows physical interpretation of the model parameters obtaining through fitting.…”

Artificial Intelligence Techniques in Solar Energy Applications

“…When compared with non-fuzzy models of solar irradiance, the fuzzy model shows an improved performance, and when compared with experimental data, the performance can be evaluated by fuzzy indices that take into account the uncertainty of the data and the model output. A fuzzy model of solar irradiance on inclined surfaces has been developed by Gomez and Casanovas (2003). The fuzzy model includes concepts from earlier models, though unlike these, it considers non-disjunctive sky categories.…”