## 3 Results and Discussion  
### Power Consumption Results  
The graphs of the power consumption over time during fermentation (Figure 9; Tables 3 and 4) are quite clear in their interpretation. The electric motors used were those of the transfer pump and the diffuser in the wine tank with this circulation system and those of the compressor in the wine tank with the pneumatic system. In the first case, the average active power consumption was 11.0 kW (Figure 10; Table 5), corresponding to an energy consumption of 197.0 kWh and a specific consumption of 0.20 kWh/hL (Table 3). Similar electrical consumption of pumps was found in another study carried out on pneumatic presses. In the second case, however, the average active power consumption was 25 kW (Figure 10; Table 4), corresponding to a power consumption of 2.6 kWh, a specific power input of 0.025 kW/hL, and a specific power consumption of 0.0026 kWh/hL (Table 4). The specific consumption of the pneumatic system is 80 times lower, thanks to the particularly energy-efficient method of breaking the cap. In fact, 378 insufflations, each lasting 1 s, were sufficient to carry out the disintegration operations (Figure 11) of a solid mass that, in a 1000 hL wine tank, often exceeded a thickness of 1.5 m. In addition, the technique used allowed for the use of a centralised compressed air system, rather than low-power machines on board the wine tank, with the advantage of having a high-power compressor that always runs at the optimum speed with maximum power factor. In addition, the pneumatic system allowed for punctual insufflation interventions, depending on the density monitoring of the must wine under fermentation (Figure 10). On the other hand, in the pump-over system, the interventions were programmed over time, with the possibility that some of them may be superfluous or, on the contrary, insufficient. Figure 10: Electrical power consumption during the first and last pump-over (**above**) and during the interventions of the compressor of the compressed air plant (**below**). During the racking phase of the tank in which the pump-over was carried out, the pomace extraction unit had to run for 110 min, with an average power input of 1.16 kW (Figure 12; Table 3) and a power consumption of 2.12 kWh or 0.0021 kWh/hL (Table 3). On the other hand, the tank extractor using the pneumatic system operated for 45 min, with an average power input of 1.57 kW (Figure 12; Table 4) and a power consumption of 1.23 kWh, or 0.0012 kWh/hL (Table 4), i.e., almost half the power consumption in the latter tank. This can be explained by the different consistency of the unloaded mass, which, in the case of the pneumatic system, was more liquid, with a higher percentage of suspended solids, and could be easily unloaded by gravity. On the other hand, in the tank where the pump-over was used, the pomace was more consistent and, therefore, a lower percentage of solids was removed with the liquid, requiring a longer and more energetic action of the extraction unit. Figure 11: Variation in density over time (blue line) of must wine in fermentation during the test in the fermenter where the pneumatic system was used; the red vertical lines correspond to the injections of compressed air (total no. 378). Figure 12: Electrical power absorption of the marcs extraction unit during racking: in the fermenter where pump-over was performed (**left**) and in the fermenter where compressed air was used (**right**). The above was also confirmed by the evolution of the energy consumption of the draining-pressing lines (Figure 13; Tables 3 and 4). In fact, during the processing of musts from the fermenters undergoing cracking, after a short start-up phase, there was a succession of two phases, in which the active power absorbed by the line was between 2.0 kW and 4.5 kW, for a total duration of about 90 min; this trend was interrupted for about 10 min between phases, during which the line absorbed an average of 10.2 kW (Figure 13).