Calculation sequence
Step-by-step method
- Multiply entered power by average load factor.
- Multiply average power by operating hours.
- Multiply energy use by the entered energy rate.
CommissioningBeginnerCross-Discipline Energy
Energy Cost Calculator
Estimate energy use and consumption cost from power, operating hours, load factor, and an entered energy rate.
Why it matters: Energy-cost screening should keep entered tariff assumptions separate from measured equipment performance.
Calculated result
Engineering evaluation
Estimated energy-consumption cost (K)18,000 $
- Average operating power (Pavg)
- 75 kW
- Estimated energy use (E)
- 150,000 kWh
Engineering interpretation
Estimated consumption is 150000 kWh at an energy cost of $18000. This screen excludes demand charges, fixed fees, taxes, ratchets, time-of-use periods, and escalation unless embedded in the entered rate.
Important limitations
- Use the applicable utility tariff or marginal rate for decision-making; a blended bill rate may not represent avoided cost.
Engineering knowledge center
Understand the calculation—not just the answer
Governing relationships
Pavg = P(LF/100)
E = Pavg H
K = EC
Current substitution
Pavg = 100(75/100) = 75 kW; E = 75×2000 = 150000 kWh; K = 150000×0.12 = $18000.
Equation legend
Inputs and calculated quantities
- P
- Connected or measured power — kW
- H
- Operating hours — h
- LF
- Average load factor — %
- C
- Energy rate — $/kWh
- K
- Estimated energy-consumption cost — $
- Pavg
- Average operating power — kW
- E
- Estimated energy use — kWh
Applications
How this calculation is used
Building design
Compare preliminary operating-cost scenarios.
Construction
Estimate the cost implication of schedules or temporary operation.
Commissioning
Translate verified power and runtime into a transparent consumption-cost estimate.
Quality controls
Assumptions and limitations
Assumptions
- Entered values represent the same stable operating condition.
- Measurements and reference values use consistent units and boundaries.
Limitations
- This is a screening and field-verification tool, not an automatic acceptance decision.
- Project criteria, manufacturer data, governing standards, and measurement uncertainty remain controlling.
Field use
Verification procedure
- Confirm the approved reference values and test boundary.
- Stabilize the system and record calibrated field measurements.
- Review calculation assumptions, uncertainty, and supporting evidence before disposition.
Common engineering mistakes
- Comparing readings taken at different loads, modes, or reference conditions.
- Treating a calculated status as proof of code, contract, or manufacturer compliance.
Technical basis
References and source standards
- U.S. Energy Information Administration—Energy ExplainedFederal reference for energy quantities, use, and cost concepts; users must enter the applicable utility tariff and demand terms.
Engineering calculation disclaimer
These engineering tools are provided for educational, preliminary evaluation, field verification, and commissioning support. Results depend on the accuracy of user-entered information and the assumptions stated for each calculation. Every colored status and comparison is a screening indicator only; project criteria, contract requirements, applicable codes, manufacturer instructions, measurement uncertainty, and authorized engineering judgment govern. The tools do not replace project-specific engineering analysis or the judgment of a licensed professional engineer.
Read the full use and limitation statement