Time-of-Day Load Shifting & Demand Charge Sheet

How to read this sheet

Energy is charged per unit at the rate of the window it was drawn in; maximum demand is charged on the highest simultaneous draw of the month whenever it occurred. Shifting a load changes the first in a way everyone quotes and the second in a way nobody does, which is why both are reported and the net is the headline. Loads placed in the same window are taken to run together - the conservative reading, and the one a demand meter agrees with, since a meter records the coincident peak and not an average. Where the loads in a window genuinely interlock rather than overlap, the real peak is lower than this sheet shows and the case for shifting is stronger than it reports. Continuous loads must be entered: they draw in every window and form the base that every shiftable load is added to, and omitting them understates every peak on the sheet. A load cannot run longer than the window it is placed in - an eight hour off-peak window will not absorb a twelve hour load - so the arithmetic is capped at the window length and the load is flagged rather than the shortfall being absorbed silently. What is not modelled: the demand ratchet many tariffs apply, which bills a fraction of the highest peak of the preceding year and makes a single bad month expensive for eleven more; any contracted demand ceiling and the penalty for exceeding it, which the load schedule tool on this site handles; and whether the process can actually be run at the proposed hour, which is a production question and not an electrical one.