It all depends on what temperatures you are cooking at.
At higher temperatures 450-600˚F / 230-315 C the grills use 3-4 lbs / 1.5-2 kg per hour. When smoking over longer periods of time at lower temperatures (200-300˚F / 95-150C), the grills use 1-2 lbs / 0.5-1 kg per hour. Our pellet bags are 20 lbs / 9kg, which powers your grill for about 15-20 hours for smoking and about 6 hours per bag when searing.
Please note: them, these are approximate informations.