Energy & Sustainability
Compressed Air Energy Cost & Efficiency
Calculate total energy cost of a compressed air installation and identify cost drivers. Compressed air is typically the most expensive utility in a factory.
Units:
Compressed air is 7–10× more expensive per kWh of delivered work than direct electric drives. Specific power for a typical screw compressor: 6.5–7.5 kW per 100 nl/min. Every 1 bar reduction in system pressure saves approximately 6–8% compressor power.
E_specific [kW per 100 nl/min] = P_motor / (Q_actual / 100) | Cost = E_specific × Q × hours × price
Input
Compressor motor power iInstalled motor power of the compressor in kW.
kW
Compressor free air delivery iFree air delivery (FAD) of the compressor at rated pressure in nl/min.
nl/min
Average load factor iPercentage of time the compressor runs loaded vs. unloaded. Measure by logging. Idle running wastes 15–25% of rated power.
%
System pressure iSet working pressure of the compressed air system in bar. Each bar reduction saves ~7% compressor energy.
bar
Annual operating hours iTotal hours the compressor runs per year.
h/year
Energy price iIndustrial electricity tariff in €/kWh.
€/kWh
Result
Specific power [kW / 100 nl/min]
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Annual energy consumption [kWh/year]
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Annual energy cost [€/year]
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Actual cost per m³ compressed air [€/m³]
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Potential saving at −1 bar [€/year]
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Annual CO₂ emissions [t CO₂/year]
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