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Interruptible Service Rider

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» Interruptible Capacity Credits
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» Interruptible Rider Agreement
» Terms of Service
» Rules and Regulations

» Click here to download the Interruptible Service Rider Agreement


The Interruptible Service Rider (this "Rider") is available as a pilot programme for two (2) years to customers in the Secondary Voltage Power (SVP) and Large Power (LP) tariffs ("eligible customers"), as follows:

(a) to eligible customers with a Billing Demand in excess of 300 kVA and a Monthly Interruptible Demand of not less than 100 kVA; and

on a first-come first-serve basis up to a maximum of twenty (20) customers whose total installed capacity shall not exceed 10,000 kVA.

All of the provisions of the applicable SVP and LP tariffs will apply except as amended by this Rider.

Customers on the Time-of-Use Tariff are not eligible to participate under this Rider.


To be eligible, customers must be able to demonstrate the ability to reduce their load to the Firm Demand Level (FDL) within 30 minutes of being notified to do so via the communication channel agreed between the customer and the Company. The minimum FDL shall be zero. The customer shall not be required to exceed 240 hours of interruption in a contractual year.

Power Interruption Notification

The Company will notify the customer, using an agreed method, of the time the customer will be required to interrupt their load at least thirty minutes in advance and will notify them, at an appropriate time, when the interruption will end.


The Company will credit the customer for their Monthly Interruptible Demand (MID) at the following rates:

(a) $12.00 / kVA ($14.10 VAT inclusive) of Monthly Interruptible Demand (MID) for customers agreeing to be interrupted between 8.00 am and 9.00 pm on any day except Saturdays, Sundays and public holidays.

(b) $9.00 / kVA ($10.58 VAT inclusive) of Monthly Interruptible Demand (MID) for customers agreeing to be interrupted between 8.00 am and 4.30 pm on any day except Saturdays, Sundays and public holidays.


The Monthly Interruptible Demand (MID) is the difference between the Average Demand (AD) and the Firm Demand Level (FDL)


The Average Demand (AD) is the number of kilowatt hours (kWh) consumed by the customer for the billing period divided by the number of days (DOS) in the billing period times 24 hours minus the number of hours interrupted in the month (Ih) and divided by power factor of 0.85:

AD = (kWh/(DOS*24-Ih))/0.85

The Firm Demand Level (FDL) is the kVA demand level established between the Company and the customer that specifies the load limit of interruption. The customer must reduce the demand to this level or below during periods of required reductions.


In the event the Monthly Interruptible Demand (MID) is less than the minimum of 100 kVA no credit will be paid for that month.


Customers who wish to participate in this programme must register for this Rider. Those eligible customers selected by the Company to participate in the pilot programme must enter into an interruptible rider agreement with the Company (the Agreement) for a contract period of not less than one year (the initial contract) provided that the initial contract must terminate by the end of the pilot programme. A customer may request termination of the contract by giving the Company two (2) months notice of its desire to terminate the contract.

In the event that the Company notifies the customer of an interruption and the customer fails to reduce power usage as required by the Agreement, no monthly credit will be issued for the month in which the customer failed to reduce power usage. In addition, the value of the credit that would otherwise have been afforded to the customer had it reached its FDL during an interruptible period for that billing month, will be billed to the customer.


The minimum contract period for this Rider is one year. At the end of the pilot programme the Company will review the experience it has gained from the programme and determine whether to continue to offer this Rider. Customers will be advised accordingly. If the Company decides to proceed with new arrangements, the customer will be required to enter into a new contractual agreement with the Company.


Service under this Rider is subject to the orders of the Fair Trading Commission and the latest publication of the "Information and Requirements Covering Installation of Electric Services and Meters". In case of a difference of interpretation between any provision of this Rider and the "Information and Requirements Covering Installation of Electric Services and Meters" booklet the provision of this Rider shall be deemed to apply. A bill calculated under this Rider is subject to change as may be approved and / or amended by the Fair Trading Commission under the provisions of applicable riders.