## 3 Results and Discussion
### Energy Demand Forecasts  
Once the evidence of including socioeconomic variables to improve energy demand predictions is retrieved, three different approaches were considered: weekly, daily and hourly forecasts (Figures 5-7).  
Figure 4: Histogram of the residuals for all customers (ALL, left) and the sum of the residuals of each ACORN individually (right).  
Figure 5: Energy consumption observations (kWh, black line) across the latest 270 days of data against RF mean predictions by week of the year (average 24 h and 7 days observations) for each ACORN group (blue line). Represented observed data are average values. Error bars represent predictions square deviation of the 24 h and 7 days average observations.  
Considering the errors made in weekly predictions, it is especially significant how the errors are very low for the first five weeks but they start increasing from then to the week number ten, when there is no only an error increment but also a remarkable deviation between the prediction and the real value, indicating the temporal limit of the algorithms applicability. For both weekly and daily predictions, ACORN E presents very high deviations from observation, which indicates the model does not perform well. ACORN F also suffers a slight deviation, especially for the intermediate period during the week number ten, which is not a significant difference between the prediction and the real value, indicating the temporal limit of the algorithms applicability.  
Figure 6: RF mean predictions by day of the week (average values of 24 h observations) for each ACORN group across the latest 270 days of data. Error bars represent predictions square deviation considering average 24 h errors.  
Figure 7: RF mean predictions by hour of the day for each ACORN group across the latest 270 days of data. Error bars represent predictions square deviation.  
validation, while the other groups are very adjusted to expected values. ACORN E and F are also the ones with higher demands, which could indicate that the groups of high social status do not have the highest needs as their households are more energetically sustainable, there are additional variables not considered in this study that could be influencing consumption for middle class population.  
Hourly forecasts follow a different pattern to the previous predictions for all groups, with a clear variation of consumption along the day, emphasizing daily predictions miss important information for short term applications. In general terms, errors rise during the evening (15.00-20.00) coinciding with the hours of maximum energy demand, due to a more variable behaviour not covered by the meteorological or general socioeconomic variables studied. Nevertheless, the errors remain low for all groups but again ACORN E, emphasizing the need of more information to characterize this group. Heterogeneity of members of ACORN E must be affecting the prediction, which is defined as \"Career Climbers\"; young people, single couples, and families with young children who own mortgages on apartments, flats, or small houses, living normally in urban locations. It is surprising that in general, energy demand for ACORN E is higher than groups A or B, with higher socioeconomic status, but considering the model uncertainties and the residuals bias, this group must be not well characterized and a deeper analysis should be made to detect undetected subgroups.