In the industrial plant context, especially in the case of a large increase in production, the risk of layering new acquisitions on top of an existing layout without questioning previous choices can lead to increasing inefficiencies. Under these conditions, the analysis of power demand in a reference period is a useful activity to be carried out. Therefore, a very fast and easy approach, based on the analysis of the energetic behaviour of an existing plant, in the present case a wine production facility, is proposed here with the aim to support management in addressing efficiency choices. It foresees, first of all, the acquisition of electricity consumption printouts, relevant to the last few years and detailed up to the day, from the national energy provider. Then, thanks to some analysis on weekly, monthly, seasonal and/or yearly trends, it is possible to evaluate: the basic power absorption levels (e.g. due to the plant auxiliary services, production machinery, product storage cells), the surplus power absorption levels due to seasonal trends (i.e. due to different environmental weather conditions) and the peaks due to the core production activities (concentrated mainly during the autumn, i.e. after the grape harvest). This approach allows connoting an industrial plant basically with two metrics, i.e. numerical parameters, both mathematically expressible as ratios between homogeneous quantities referred, respectively, to power demand levels and to periods of the year with different power demands. In the examined case, the analysis revealed a strongly-connoted yearly trend that evidences the existence of two, very different periods: an ordinary and an extraordinary period, corresponding to the grape harvesting term, having a “duration ratio” of 0.18 (18% of the year) and a “power request level ratio” of 4 (+300% of increment on the average request). The period with the higher request is, therefore, very short but intense in its power demand. This first analysis, together with the “weekly normalized average profile of power request” (second tool belonging to this methodology), allow evidencing: (1) the contribution of the activities, related to the wine making process, to the net increase of power demand, and (2) the possibility to flatten the weekly trend, now having a decrease of about 0.45-0.50 normalised power units between the working week and the weekend, by attributing some consumption to Saturdays and Sundays, e.g. by providing for a different staff rotation.