“…Gonz alez-Gonz alez et al (2014) analyzed the energy self-sufficiency for the hybridization of biogas and photovoltaic system focused on a pig slaughterhouse; however, this study did not consider the types of roof in implementing PV system (Gonz alez-Gonz alez et al, 2014). Hassanain et al (2011) analyzed the solar thermal energy storage effect based on the roof type (gable roof, flat roof, or dome roof), but did not analyze the implementation of the PV system (Hassanain et al, 2011). Gupta and Chandra (2002) analyzed the energy-saving effects of different roof types (gable roofs, Quonset roofs, and gothic arch roofs) and orientations (east-west and north-south), but did not analyze the implementation of the PV system (Gupta and Chandra, 2002).…”