Electricity Cost Formula for Factories
How to calculate factory electricity cost from load, operating hours and tariff.
The Formula
Energy (kWh) = Power (kW) × Time (hours)
Cost (₹) = Energy (kWh) × Tariff (₹/kWh)
For motors:
Actual Power (kW) = Rated kW × Load Factor% × (100 ÷ Efficiency%)
Factory-Level Example
Connected load: 200 kW, demand factor: 75%, operating 8 hrs/day, 26 days/month, tariff: ₹8/kWh.
Actual Demand = 200 × 0.75 = 150 kW
Daily Energy = 150 × 8 = 1,200 kWh
Monthly kWh = 1,200 × 26 = 31,200 kWh
Monthly Cost = 31,200 × ₹8 = ₹2,49,600
Indian Industrial Tariff Components
| Component | Basis | Typical Range |
|---|---|---|
| Energy charge | Per kWh | ₹5–10/kWh |
| Demand charge | Per kVA of max demand | ₹150–400/kVA |
| Fixed charge | Per month | ₹500–5,000/month |
| PF penalty | If PF < 0.90 | 1–2% per 0.01 drop |