This work presents a detailed analysis of a south-facing photovoltaic field with a fixed tilt angle, carried out through hourly simulation using the TRNSYS software and real meteorological data corresponding to the Pico Polio site (Asturias, Spain), provided by HUNOSA. The main objective is to characterise, with high temporal resolution, the energy behaviour of the photovoltaic field and to assess its response to the variability of local solar resources. The adopted methodology includes the implementation of a photovoltaic generation model based on a simplified formulation of the single-diode model, which estimates the instantaneous electrical power as a function of the tilted global irradiance and the module temperature (De Soto, Klein & Beckman, 2006; Duffie & Beckman, 2013). The hourly meteorological data includes irradiance, ambient temperature, and wind speed, and are processed to obtain annual energy performance time series. The simulation was conducted for a complete year, allowing the analysis of daily and seasonal production, as well as the characteristics of the generation curve under real radiation conditions. The results show how the south-facing orientation and fixed tilt influence the utilisation of solar resources, with maximum production peaks during summer and a significant reduction in winter, together with well-defined daily behaviour. The importance of intra-daily resource variability is discussed, as well as the ability of the model to capture irradiance fluctuation dynamics and their effect on instantaneous power output. This study not only provides an assessment of the performance of a photovoltaic field under real operating conditions in northern Spain but also offers a methodological basis for comparing different photovoltaic system configurations and their responses to climatic variability, thereby contributing to efficient system design and informed energy planning decisions.