Decomposition of the 605 kW Base-to-Peak Load Gap in a Hospital Building: Evidence of Occupancy Schedule Dominance over Cooling Load in Demand-Side Management Strategies

Abstract

The reliability of a hospital's power supply hinges on the accurate determination of backup source capacity; however, standard design practices typically rely on static installed power values ​​without accounting for dynamic load fluctuations. This study characterizes the electrical load profile of a healthcare facility using a reference load profile derived from building energy simulations, comprising 8,760 hourly observations over a full year. The analysis procedure includes timestamp validation, power balance verification, end-use decomposition, descriptive statistics for weekday and weekend profiles, percentile-based clustering to distinguish between base load (5th percentile) and peak load (95th percentile) regimes, and vulnerability zone mapping via load duration curves. The recorded average load was 1,156.3 kW, with an annual peak of 1,576.2 kW and a load factor of 0.734. The dynamic range between the base load (880.2 kW) and peak load (1,484.9 kW) was 604.7 kW (38.4% of the peak load), while the non-sheddable vital load measured 695.7 kW. Decomposition of this range revealed a decoupling between energy share and peak contribution: cooling systems accounted for 43.3% of annual energy consumption but contributed only 10.4% to the dynamic range, whereas lighting and interior equipment collectively contributed 59.7%. The weekend load deficit was only 14.7% (177.4 kW) and was concentrated during active hours; the difference was less than 1% during nighttime hours but reached 26.9% at 16:00. Vulnerability mapping indicates that a 17.5% reduction in generator capacity is achievable through a maximum load shed of 276.2 kW, all of which falls within the category of deferrable loads. These findings shift demand-side management priorities toward scheduled loads rather than air conditioning systems.