Problem 1
The following is an electric rate tariff for larger industrial customers
Meter Charge: $745/billing period
On – Peak Energy Charge
$0.05 for the first 100,000 kWh
$0.07 for the next 900,000 kWh
$0.095 for all remaining kWh $12.00 per kW demand charge per billing period
Off-Peak Energy Charge
$0.015/kWh for ALL Power No Demand Charge During Off Peak Periods
A. What will the customer’s bill be for a single month when they consume:
1,463,000 kWh On-Peak, 1,381,000 kWh Off Peak, Max Demand (On-Peak) at 12,900 kW
$________________
B. Assuming a 30 day billing period, what is the customer’s load factor _%
Problem 2
The customer in adding an ice storage cooling system to his building. In this system, the air conditioning load will be entirely handled by making ice at night (off- peak) and using the ice for cooling during the following day. By doing this, the customer will entirely remove his current chiller which currently operates as needed entirely on peak.
• The old chiller draws 925 kW at full load and over the course of the 6 month cooling season consumes 6000 kWh per weekday (all on-peak) (but is not operated on the weekend). Assume the old chiller hit full load at least once during each month.
• The new ice storage chiller has the same maximum demand and the same overall energy consumption but will only run during the off peak period
• Nothing else changes in the building.
Assume a 30 day billing period, which includes 22 weekdays exactly. Use the utility rates shown in Problem 1.
What is the monthly energy consumption of either chiller? _______________kwh/mo.
Before changing out the chiller, the customer had the consumption profile in Problem 1. We now want to recalculate the customer’s total electric bill for months during the cooling season after the conversion to the ice storage chiller.
a. The total on-peak electric consumption for a month is now _____kwh/mo. b. The total off-peak electric consumption for a month is now ___________kwh/mo. c. The total demand for a month is now ___________kw/mo. d. What is the electric bill for the month now? $__________/mo.
e. How much will the customer save by this move?? $________________/mo.