Annual Usage & Energy Rates
System Data
Annual Compressor Usage, hrs./yr.
Gas System
Electric System
Average Energy Rates
Full Load Power, hp
Natural Gas, $/MMBtu
Gas Need@Full Load, Btu/hp-hr
Electric Energy, cents/kWh
Motor Efficiency, %
Electric Demand, $/kW/month
Auxiliary Power, kW
Installed Capital Cost, $
Maintenance Cost, cents/hp-hr.
Assumptions upon which this calculator is based.
Heat Recovery, %
Annual Energy Cost, $
Annual Electric Demand Charge, $
Annual Maintenance Cost Premium, $
Total Annual Operating Cost, $
Annual Savings from Gas System, $
Annual Return on Incremental Investment in the Gas System, %
Payback Period for Incremental Investment in the Gas System,Years


Gas need for an engine can vary from 10,000 to 6,500 Btu/hp-h depending on the engine size and design. Generally, hourly gas need per horse power for a larger size engines is lower than that for a smaller engine. Refer to the Buyers’ Guide for specific information on various models for different manufacturers. For a quick preliminary analysis, one could use 7,600 Btu/hp-h.