The fluorescent systems in there are likely older and less efficient, so at the lower end of the range. For this kind of industrial setup you can probably do mo

The fluorescent systems in there are likely older and less efficient, so at the lower end of the range. For this kind of industrial setup you can probably do more efficient DC directly to the lights with fewer and more efficient conversions from AC, and there may be other improvements available (solar tubes, dimmable LEDs, task lighting, etc.). 7x seems high but likely achievable.