Premises

Air lost to leaks	About 10 percent of the compressors' electricity is lost to leaks that can be found and fixed. We heard no leak on the walk, so this share is assumed. The guidance puts leaks at 20 to 30 percent of the air where nobody looks for them. If this is wrong: the reading at a meal break finds the compressors pumping for less than about two of twenty minutes, and there is little to find.
Pressure above the need	The compressors' setting stands about 6 psi above what the presses need. We read no gauge and no panel, so these psi are assumed and there may be none. If this is wrong: the panel's pressure is within a few psi of the highest set at any press, and the setting stays where it is. Each two psi that does come off is worth about $720 per year.
Compressors' share of the bill	About 12 percent of the electricity bill goes to the compressors. The bills give one total for the plant, so this is our estimate from the compressors' rated power. If this is wrong: the running hours on each panel add up to less, and the figure falls with the share. Each point of the share is worth about $780 per year.