A 75hp shaft output motor that has an efficiency of 919 perc

A 75-hp (shaft output) motor that has an efficiency of 91.9 percent is worn out and is to be replaced by a high-efficiency motor that has an efficiency of 95.4 percent. The motor operates 5, 440 hours a year at a load factor of 0.66. Taking the cost of electricity to be $0.070/kWh, determine the amount of energy and money saved as a result of installing the high-efficiency motor instead of the standard motor. Also, determine the simple payback period if the purchase prices of the standard and high-efficiency motors are $4, 542 and $5, 338, respectively.

Solution

we firt find energy cost for old motor with efficiancy 91.9 % =0.070*5440 in ayear....1

and for 95.4% efficiancy motor we find total cost.....2

then we substract 2 from 1 to get cost saved then we convert this cost to how much hr motor work inthis cost .this requred solution for energy savings

and already above we discused cost saving