Maximum Demand Calculation -

For an electrical engineer or facility manager, performing a maximum demand calculation involves four key steps:

Demand charges typically constitute 30–60% of a commercial/industrial electricity bill. For example:

Maximum Demand (MD) is the highest level of electrical power consumed by a facility within a specific time interval during a billing period. Accurate calculation of MD is essential for sizing electrical infrastructure (transformers, switchgear, cables) and for minimizing utility costs, as many commercial and industrial rates are based on peak demand charges. This report outlines the definitions, calculation methodologies, and strategies for managing maximum demand. maximum demand calculation

For HVAC (often 40-60% of MD), make ice or chill water at night. Use that stored cooling during daytime peak hours. The chiller compressor runs at night (off-peak), reducing daytime MD by hundreds of kW.

Maximum Demand (MD) is the highest average power (kW, kVA, or A) drawn by an electrical installation over a specified time interval (typically 15, 30, or 60 minutes) during a billing or assessment period. For an electrical engineer or facility manager, performing

Key distinction: MD is not the instantaneous peak (which may last milliseconds), but the sustained peak over a sliding window (e.g., 30 minutes). Utilities use MD to size transformers, cables, and to penalize industrial users for poor load factor.

| Application | Typical Interval | Notes | |--------------|------------------|-------| | Residential | 15 or 30 min | Often not metered for demand | | Commercial (retail, offices) | 15 min | High granularity | | Industrial | 30 min | Most common worldwide | | Large industries (steel, cement) | 60 min | Smoothes heavy transient loads | | Generator sizing | 30 min | Sustained load capacity | Maximum Demand (MD) is the highest average power

Utility example (typical): If your 30-minute average load is 500 kW at any point in the month, that becomes your billed MD for the month — even if the rest of the month is 200 kW.