The interruptible rate (INTR) is available to all commercial, industrial, and governmental customers contracting for electrical service for a period of one year or more and having an interruptible load with a measured demand of 100 kW or more.

The interruptible rate schedule is used in conjunction with the Medium General Service (MGS), Large General Service (LGS), and Large Industrial Service (LIS) firm power rate schedules. To qualify, customers must have a minimum of 100 kW of interruptible demand. RPU reserves the right to limit the amount of interruptible load, which may be nominated.

Customers nominate either an interruptible demand amount or a firm demand amount. Customers nominating an interruptible demand amount shall be required to interrupt at least the amount nominated, or their total load if their total load is less than the amount nominated. In nominating the firm demand amount, customers shall be required to interrupt an amount sufficient to bring their load to or below the firm demand nominated. In no case shall the INTR rate be made available to customers with less than 100 kW of interruptible load.

All interruptible loads recognized under the INTR rate schedule shall be electrical loads that are coincident with RPU's system peak. Electrical loads occurring outside this peak period shall not qualify for the INTR rate. Any generation equipment used by the customer to qualify for the INTR rate shall be located at the site of the interruptible load such that RPU does not have to use its electrical facilities to transmit power for the customer.

The service must be three phase, 60 Hertz, alternating current at one of the standard secondary service voltages as described in RPU's published Electric Service Rules and Regulations. Service is subject to interruption at the sole discretion of RPU at any time during the year. There will be no more than 175 hours or 35 interruptions per year.

Customers approved for metering at 13.8 kV will receive a discount of 1.25 percent on base rate charges for measured demand and energy.

MSG and LGS customers owning transformers will receive a credit of $.20 per kW on each month's measured demand.

The customer agrees to maintain an average power factor of 0.95 or greater for the billing period and to prevent a leading power factor. If the customer's average power factor is less than 0.95 for the billing period, the billing demand will be determined by multiplying the measured demand by 0.95 and dividing the results by the customer's average power factor. The average power factor is defined to be the quotient obtained by dividing the kWh used during the month by the square root of the sum of the squares of the kWh used and the lagging reactive kilovoltampere-hours supplied during the same period. The customer's average power factor will be determined by means of permanently installed meters.

Bills computed under this rate schedule are subject to adjustment in accordance with the Power Supply Adjustment (PSA).

Customers whose service is taken outside the Rochester City limits are subject to a 10% surcharge on their bills (excluding charges computed under the Power Supply Adjustment).

Unauthorized use of electricity during a peak period of service interruption ordered by RPU will require the customer to pay a penalty (in addition to standard charges) which is reflective of the uninterrupted load's cost impact on RPU's wholesale power cost from SMMPA over the ensuing 12 months:

  • No impact – No penalty.
  • Occurs on monthly peak – Uninterrupted kW contribution to RPU's peak billed at SMMPA rate.
  • Occurs on annual peak (as determined by analysis from October 1 analysis of summer demands) – Uninterrupted kW contribution to RPU's annual peak is additionally penalized at two times SMMPA rate and added to participants October billing.

Exception for first-time participants in an RPU peak reduction rate who have interruptible nominations of less than 500 kW. The penalty for failure to interrupt will be waived during the initial 24 months.