Topics from the Power Line

Editor's note: The Energy Services Bulletin features real answers to real questions posed to our staff at the Energy Services Power Line. We hope you find it useful.

Question:

How much does the electricity cost to run a 1.5 horsepower pump, eight hours a day? I am thinking about getting an above-ground swimming pool and would like to know how it might affect my energy bill.

Answer:

Thank you for asking Western's Energy Services Power Line about energy use of the swimming pool pump.

Here's a simple formula you can use to evaluate the costs:

1. size of motor X kilowatts per horsepower X motor efficiency rating X number of hours motor runs per day = kWh used by motor per day
   
   
2. kWh used by motor per day X cost of energy = daily cost to run the motor.
   

Let's assume an 80-percent efficient, 1.5 HP motor, running eight hours a day.

1.5 HP (size of the motor) X .7456 (kilowatts per horsepower; 1 HP = 745 watts) / .8 (80 percent efficiency) X 8 (hours) = 11.2 kWh (kilowatt hours used by the motor each day. Multiply 11.2 by the energy charge to get the cost per day.

Based on a cost of 10 cents per kWh, running the pump would cost $1.12 for eight hours.