code: def add_peak_demand(self):
          
          peak_load = peak_load_satellites = 0
          for lv_load_area in self.lv_load_areas():
              peak_load += lv_load_area.peak_load
              if lv_load_area.is_satellite:
                  peak_load_satellites += lv_load_area.peak_load
          self.peak_load = peak_load
          self.peak_load_satellites = peak_load_satellites
docs: Summarizes peak loads of underlying load_areas in kVA.
          
          (peak load sum and peak load of satellites)