Question 9.9: The facility of Example 9.6 has an option of owning and oper......
The facility of Example 9.6 has an option of owning and operating its own service transformer with the advantage of reduced rate structure as described here:
• Customer charge: \$650/month
• Demand charge: \$15/kW
• Energy charge: \$0.025/kWh
Calculate the reduction in the utility bill during the month for which the energy use characteristics are given in Example 9.6. In the savings calculation, do not consider the power factor clause, ratchet clause, sales tax, and fuel cost adjustment.
First, the utility bill is determined in the case the facility owns its service transformer:
(a) Customer charge=\$650.00
(b) Demand charge=400 \ kW*\$15/kW=\$6000.00
(c) Energy charge=50,000 \ kWh*\$0.025/Wh=\$1,250.00
Total monthly charges =(a)+(b)+(c)=\$7900.00
Thus, the savings in the utility bill for the month are
Utility bill savings = \$9950-\$7900=\$2050
A LCC-based economic analysis may be needed to determine the cost-effectiveness of replacing or owning transformers.