Calculators › Utility bills and rates On-peak runtime within an energy-cost limit calculator
On-peak runtime within an energy-cost limit
Maximum on-peak running hours is calculated as [C_limit−P × H_total × r_off]/[P × (r_on−r_off)]. Use the stated system boundary and matching input units.
H on,max = C limit − P × H total × r off P × ( r on − r off ) H_{\text{on,max}} = \frac{C_{\text{limit}} - P \times H_{\text{total}} \times r_{\text{off}}}{P \times \left(r_{\text{on}} - r_{\text{off}}\right)} H on,max = P × ( r on − r off ) C limit − P × H total × r off
Calculator
Enter the values you know and leave one box empty. Calculate finds the empty one, the result or any input.
Worked example
Given
C limit C_{\text{limit}} C limit 64 $ P P P 50 kW H total H_{\text{total}} H total 10 h r off r_{\text{off}} r off 0.08 $/kWh r on r_{\text{on}} r on 0.2 $/kWh H on,max = 64 − 50 × 10 × 0.08 50 × ( 0.2 − 0.08 ) = 4 H_{\text{on,max}} = \frac{64 - 50 \times 10 \times 0.08}{50 \times \left(0.2 - 0.08\right)} = 4 H on,max = 50 × ( 0.2 − 0.08 ) 64 − 50 × 10 × 0.08 = 4
Symbols and units
Symbol Meaning Unit
H on,max H_{\text{on,max}} H on,max maximum on-peak running hours h C limit C_{\text{limit}} C limit total batch energy-cost limit $ P P P constant batch input kW H total H_{\text{total}} H total required total running time h r off r_{\text{off}} r off off-peak energy price $/kWh r on r_{\text{on}} r on on-peak energy price $/kWh
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