Calculating the Annual Electricity Cost of a Compressor
Understanding the Calculation Process
Given Data:
Power of compressor: 75 hp
Operating time: 2500 hours/year
Efficiency of electric motor: 93%
Unit cost of electricity: $0.11/kWh
Step-by-Step Calculation:
1. Calculate Energy Consumption:
First, convert the power of the motor from horsepower (hp) to watts:
1 hp = 746 watts
Power in watts = 75 hp x 746 = 55,950 watts
Now, find the energy consumption using the formula:
Energy Consumption = Power x Time
Energy Consumption = 55,950 watts x 2500 hours = 139,875,000 watt-hours
Convert the energy consumption to kilowatt-hours (kWh):
1 kWh = 1000 watt-hours
Energy Consumption in kWh = 139,875,000 watt-hours / 1000 = 139,875 kWh
2. Calculate Annual Electricity Cost:
Finally, multiply the energy consumption by the unit cost of electricity:
Annual Electricity Cost = 139,875 kWh x $0.11/kWh = $15,386.25
Therefore, the annual electricity cost of this compressor is $15,386.25.