This study focuses on integrating Photovoltaic rooftops in the food sector. Addressing global energy demand, with 30% attributed to electrical energy, the study highlights the industrial refrigeration sector's significance, consuming 20–30% of electrical energy. The incorporation of renewable energies, particularly solar, holds promise for reducing fossil fuel dependence. Photovoltaic technology, with reduced costs and high solar availability, emerges as a viable solution for large and the small-scale installations, fostering self-consumption systems that enhance competitiveness in the industrial sector. The study aims to share lessons learned from the project “Development of an advanced analysis system for integrating distributed solar photovoltaic generation into the industrial sector”. The methodology uses various indices to analyse electrical demand and generation in three industries, aiming to evaluate the feasibility of integrating photovoltaic systems into industrial refrigeration. Results reveal undersized generators in these industries. The indices, restricted to sunshine hours, provide optimal values for sizing, preventing nighttime consumption from influencing outcomes. In this case, the Zero Energy Industry point in sunshine hours (ZEISH) vary between 67.59% and 68.65%, with generator powers of 44.19 kW and 69.14 kW among the industries analysed. Findings contribute to knowledge advancement in integrating photovoltaic systems in industrial environments, supporting a sustainable and energy-efficient future. Lessons learned can extend to diverse industries in the food sector, emphasizing the potential for renewable energy diversification.