Commercial energy cost inputs
This page uses a single-column layout overall. The calculator fields below switch to three columns on large screens, two on medium screens, and one on mobile.
Example data table
Use this sample profile to understand how each field can be filled before running your own estimate.
| Field | Example value | Purpose |
|---|---|---|
| Connected load | 120 kW | Total installed commercial load to be modeled. |
| Operating schedule | 10 hours/day, 26 days/month | Defines total monthly operating hours. |
| Load factor | 68% | Represents average loading across scheduled hours. |
| Peak energy share | 55% | Splits monthly kWh between peak and off-peak periods. |
| Energy rates | 0.18 peak, 0.11 off-peak | Applies time-based energy pricing. |
| Demand rate | 14 per billed kW | Prices measured or estimated demand. |
| Power factor inputs | 0.88 actual, 0.95 target | Estimates billing adjustment and capacitor need. |
| Extra charges | 0.015 fuel, 180 service, 8% tax, 2% discount | Captures surcharge and final bill modifiers. |
Formula used
Monthly kWh = Connected Load (kW) × Hours per Day × Days per Month × Load Factor
Peak kWh = Monthly kWh × Peak Share
Off-peak kWh = Monthly kWh − Peak kWh
Energy Charge = (Peak kWh × Peak Rate) + (Off-peak kWh × Off-peak Rate)
Estimated Peak Demand = max(Average kW × 1.15, Connected Load × Load Factor)
PF Adjustment kW = Peak Demand × ((Target PF ÷ Actual PF) − 1), when Actual PF is below Target PF
Billed Demand = Peak Demand + PF Adjustment
Demand Charge = Billed Demand × Demand Rate
Subtotal = Energy Charge + Demand Charge + Fuel Surcharge + Service Charge
Total Cost = Subtotal + Tax − Discount
Required kVAr = Peak Demand × (tan(arccos Actual PF) − tan(arccos Target PF))
This calculator uses a practical planning model. Actual tariffs may include ratchets, contract demand, seasonal riders, minimum billing rules, or interval-based billing methods.
How to use this calculator
- Enter your facility’s connected load in kW.
- Provide the monthly operating pattern using hours per day and days per month.
- Set the expected load factor and peak energy share.
- Enter peak and off-peak energy rates plus the demand charge rate.
- Add power factor, fuel surcharge, service charge, tax, discount, and emission factor.
- Leave peak demand blank if you want the page to estimate it automatically.
- Click Calculate Cost to show the result block above the form.
- Use the CSV and PDF buttons to export the calculated summary.
FAQs
1. What charges does this calculator include?
It includes energy charges, demand charges, fuel surcharge, fixed service fee, taxes, discount, and an estimated power factor billing adjustment. That gives a broader view than a basic kWh-only estimator.
2. Why does demand matter on commercial bills?
Commercial tariffs often bill the highest short-term load separately from energy use. A short demand spike can increase the full month’s bill, even when total kWh stays moderate.
3. What is load factor in this page?
Load factor represents how heavily your connected load is used during scheduled operating hours. Higher values usually mean steadier utilization, while lower values suggest more idle time or oversized equipment.
4. What happens if peak demand is unknown?
Leave the peak demand field blank. The calculator estimates it from average operating load and connected load. That estimate is useful for planning, but interval meter data remains more accurate.
5. How is power factor handled?
If actual power factor is below the target, the page adds an estimated billing adjustment and shows the capacitor bank size that may help correct it. Utility billing rules can differ by tariff.
6. Can I use another currency?
Yes. Change the currency symbol field to match your reporting format. The calculations stay the same, so the page works for local budgeting, management reporting, or comparative tariff analysis.
7. Are taxes and discounts optional?
Yes. Enter zero when they do not apply. This helps you model engineering-only scenarios, negotiated tariff discounts, or final payable bill values from a finance perspective.
8. Can this replace an actual utility invoice?
No. It is an estimation and planning tool. Real invoices may include ratchets, block tariffs, minimum charges, seasonal rules, contract demand, or special riders not modeled here.