The Annual Electricity Cost Calculation for a 78-hp Compressor

What is the annual electricity cost of a 78-hp compressor operating at full load for 2500 hours a year?

If the compressor is powered by an electric motor with an efficiency of 93 percent and the unit cost of electricity is $0.11/kWh, how much does it cost annually to run this compressor?

Answer:

The annual electricity cost of this compressor is $17,206.13.

To calculate the annual electricity cost of a 78-hp compressor that operates at full load for 2500 hours a year, we need to use the following formula:

Annual electricity cost = (P x 0.746 x Ckwh x h) / η

• P = Compressor power = 78 hp
• 0.746 kW/hp = Constant for conversion to kW
• Ckwh = Cost per kilowatt hour = $0.11/kWh
• h = Operating hours per year = 2500 hours
• η = Efficiency = 93% = 0.93 (decimal form)

By substituting the given values into the formula, we get:

Annual electricity cost = (78 hp x 0.746 kW/hp x $0.11/kWh x 2500 hours) / 0.93

Annual electricity cost = $17,206.13

Therefore, the annual electricity cost of running this 78-hp compressor under the specified conditions is $17,206.13.