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Who qualifies for this Rider?
This rider is available to customers taking service on the General Service Small Demand rate with a maximum billing demand of 150 KW. This rider gives smaller customers access to the time-of-use rider. The on-peak period for Rate 469S is five hours shorter than for large customers. Larger customers may use the General Service – Time-of-Use Rider - Rate 469 or Large General Service - Time-of-Use Rider - Rate 469L.
What is a Time-of-Use Rate or Rider?
Time-of-Use rates and riders operate on the fact that electricity is more expensive to generate and deliver at certain times. As OPPD moves closer to a peak condition, the costs to provide electricity increase. The time-of-use rider provides a lower rate to customers that may be able to shift some load to off-peak conditions.
OPPD’s General Service – Small Time-of-Use Rider:
While some utilities offer different energy charges for electricity used during different time-periods, OPPD uses a different demand ratchet. The time-of-use demand ratchet increases the impact of demands during on-peak periods, and reduces the impact of demands used during off-peak periods.
The on-peak period is defined as 2:00 p.m. through 7:00 p.m. on weekdays between June 1 and September 15, excluding holidays. Off-peak includes all hours not specified as on-peak.
Billing Demand for the summer months is the greatest of the following:
- The highest on-peak demand during the current month or preceding 11 months
- 33% of the highest off-peak demand of the current month
- The demand minimum from the customer's base rate
Billing Demand for the winter months is the greatest of the following:
- The highest on-peak demand occurring during the preceding June 1 through Sept. 15 time period
- 33% of the highest off-peak demand of the current month or preceding 11 months
- The demand minimum from the customer's base rate
All of these demands are subject to power factor correction.
The time-of-use billing demand is used to calculate charges on the customer's base rate.
In addition to applicable base rate charges, each time-of-use customer is charged an additional $56.40 each month to cover the cost of time-of-use metering.
Why are OPPD’s costs higher during peak conditions?
OPPD runs its lowest cost generating units as often as possible. These are called base-load plants. While base-load plants are less expensive to operate, they are expensive to build. This means that base-load plants have a high fixed cost, and low variable costs. To be cost-effective, the District needs to operate base-load plants extensively.
Utilities (including OPPD) also have peaking plants. Peaking plants are smaller generating units that only run when the base-load plants cannot supply all of the electricity needed. These plants are less expensive to build, but are more expensive to operate. This means that peaking plants have a low fixed cost, but higher variable costs.
The cost to build a plant increases fixed costs. By using the right combination of base-load and peaking plants, OPPD keeps its fixed costs low. However, as peaking plants are utilized to supply more electricity, the variable cost (the cost of the next kWh) increases.
When are OPPD’s costs highest?
OPPD’s peaking condition, and highest costs, occur during summer weekday afternoons. Therefore, OPPD’s costs are:
Higher in the summer than in the winter
Higher on weekdays than on the weekends
Higher in the afternoons than overnight or in the morning
Published OPPD Rate Schedule (PDF, opens in new window)
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