The different wattage settings let you match the brightness to the specific location. The 80W setting is sensible for smaller walkways, residential entrances, or areas that do not need very strong light. The 100W setting works well for medium entrances, pathways, and business fronts. The 120W setting should be used for larger walls, corridors, and areas where extra brightness helps with visibility or security. Adjusting the wattage helps you get the right level of light without using more energy than necessary.