What is a curtailment rider?
Some customers have the ability to reduce their load on short notice. Some customers use backup generators to supply their power needs. Others may reduce operations, lighting or air conditioning loads.
When customers lower demand during peaking periods, OPPD is able to avoid the generation of more expensive power and delay the need to build expensive generating plants. It also reduces the stress on the transmission system. OPPD passes these avoided cost savings to participating curtailment customers through credits.
Participating customers contract for a specific amount of demand they will curtail (or shed) during a peaking condition. As OPPD approaches a peaking condition, OPPD requests these customers to reduce their load. In exchange for reducing load, customers receive a credit for participation. However, there may be penalties to firm curtailment customers that do not reduce load when requested to during a curtailment period.
Why is this important?
A peaking condition is a critical event for an electric utility. OPPD must build power plants and transmission lines large enough to supply the maximum amount of electricity demanded simultaneously by our customers. This is referred to as capacity obligation. As the amount of electricity demanded gets closer to the system maximum capacity, two things happen.
First, OPPD’s systems begin to run less efficiently. Transmission lines lose more power through heat loss. The power plants must then generate even more power to compensate for the heat losses. This is like driving a car with the gas pedal to the floor. It goes very fast, but gets poorer gas mileage.
Second, OPPD begins to run its higher cost generating units (peaking plants). Peaking plants are small generation units that only run when demand nears capacity. Even though these units may be inexpensive to build, they are more expensive to operate. Therefore, as demand nears capacity, OPPD uses increasingly expensive generating units. In some cases, OPPD may have to purchase power from other utilities to meet customers’ demand.
Curtailment Rider Options
OPPD has several curtailment rider options. The customer has the option to participate on a firm or voluntary basis. These offers vary based on the size of the curtailable load, the amount of notice required for the curtailment, and the penalties for non-compliance. During an energy curtailment, the customer may also request the District to provide replacement power; such replacement power is not guaranteed. Please contact an Account Executive for details of OPPD’s curtailment rider options.
General Service - Curtailable Rider - Rate 467 (PDF, opens in new window)
General Service - Emergency Voluntary Curtailable Rider - Rate 467E (PDF, opens in new window)
Large General Service - Curtailable Rider - Rate 467H (PDF, opens in new window)
General Service - Curtailable Rider - Leased Capacity Option - Rate 467L
General Service - Voluntary Curtailable Rider - Rate 467V (PDF, opens in new window)
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