def add_lv_load_area(self, lv_load_area):
        # TODO: check docstring
        """Adds a LV load_area to _lv_load_areas if not already existing
        
        Args
        ----
        lv_load_area: :shapely:`Shapely Polygon object<polygons>`
            Descr
        """
        self._lv_load_areas.append(lv_load_area)
        if not isinstance(lv_load_area, MVCableDistributorDing0):
            self.peak_load += lv_load_area.peak_load