Classifying consumers; factors influencing demand

Significance of classifying consumers

Consumers are grouped (domestic, commercial, industrial, agricultural, street lighting, etc.) because each group has a different load pattern. Classification helps the utility to:

1. Forecast load: each class grows differently; class-wise forecasting is more accurate for generation and network expansion planning.
2. Plan the network and voltage level: domestic loads are fed at 230/400 V, medium industries at 11 kV, large industries at 33 kV and above.
3. Use diversity: different classes peak at different times (industry by day, domestic in evening), so the system maximum demand is less than the sum of individual demands; this reduces the installed capacity needed.
4. Design tariffs: energy and demand charges, time-of-day rates and power-factor penalties are set class-wise to recover cost fairly.
5. Demand side management: targeted programmes (peak shifting for industry, efficient lighting for households).
6. Operation and load dispatch: knowing which classes are on-line helps unit commitment, load shedding priority and reliability (hospitals and water supply get priority).
7. Reactive power and quality planning: industrial motor loads need capacitor compensation; commercial loads produce harmonics.

Factors influencing demand

Residential

• Household size and income; number and type of appliances.
• Weather and season (heating in winter, fans and AC in summer).
• Time of day: evening lighting and cooking peak.
• Electricity price and availability of substitutes (LPG, firewood).
• Urban vs rural location, awareness of efficient appliances (LED, inverter AC).
• Government programmes, e.g. promotion of induction cooking.

Commercial

• Type and size of business (hotel, hospital, mall, office).
• Business hours and occupancy; tourist season.
• Air-conditioning, lighting and lift loads; building design.
• Weekends and holidays; tariff level.

Industrial

• Type of process (continuous, batch) and number of shifts.
• Production level and market demand, economic conditions.
• Rating and efficiency of motors, furnaces and other equipment; power factor.
• Tariff structure (time-of-day, demand charge) and supply reliability; captive generation.
• Automation and technology level.