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Comparison between Maximum Demand Tariff and Non-residential Tariff

HK Electric has three types of tariff.  For details of the tariff structure, please click the picture below:

This section explains the structure of Maximum Demand Tariff and how to evaluate whether the Maximum Demand Tariff can help you reduce electricity charges.

Structure of Maximum Demand Tariff

Maximum Demand Tariff consists of two parts, i.e. demand charge and energy charge. The demand charge is based on the maximum demand in kVA, while the energy charge depends on the energy consumption in Unit (kWh) of the month. Tariff charges are subject to a minimum of 100 kVA of the chargeable demand.

Maximum Demand Tariff is only beneficial to electrical installations with a high load factor. This applies to accounts of considerably high electricity consumption over a long period of time with a steady load. If these conditions are not satisfied, it is possible that the electricity charge could be higher under Maximum Demand Tariff than Non-Residential Tariff.

Basic Criteria for Applying for Maximum Demand Tariff

The following basic criteria must be fulfilled for you to apply for Maximum Demand Tariff:

  1. Only applicable to Non-Residential Customers.
  2. The minimum average monthly consumption should exceed 24,000 units.

Maximum Demand (kVA) of An Installation

The Maximum Demand is expressed in kVA and will be recorded by a Maximum Demand Meter. The demand is averaged over a period of 30 minutes.

The graph below demonstrates how the demand of each 30-minute interval is measured.

Maximum Demand (kVA) of An Installation

The demand of an installation for the period under consideration
= (1 min x 1000 kVA + 20 min x 200 kVA + 9 min x 500 kVA) / 30 min
= 317 kVA(i.e. average value of kVA over 30 minutes interval)

There are thus 48 'demand' values in a day and the Maximum Demand in a month is the largest 'demand' value occurred in the month.

Comparison Between Maximum Demand Tariff and Non-Residential Tariff

Example 1

Example 1

Example 2

Example 2

1.  The above examples are for reference only
2.  Net Rate = Basic Charge + Fuel Clause Charge - Rebates

Online Calculator

Assessment of Maximum Demand

The above two examples illustrate how the value of Maximum Demand (kVA) affects the actual amount payable of the electricity bill. Therefore, customers should conduct maximum demand measurement / monitoring of their installations to ascertain there are savings made under Maximum Demand Tariff.

We strongly recommend our customers install recorders to measure the actual kVA value of their installations by registered electrical contractors and assess whether Maximum Demand Tariff is beneficial to them before applying for Maximum Demand Tariff.

Application Procedure

Customers who wish to apply for Maximum Demand Tariff after the appraisal can send an application letter to us to initiate the processing. If all the criteria for Maximum Demand Tariff are fulfilled, we will forward an application form and the Terms & Conditions for Maximum Demand Tariff to the applicant.

Upon receipt of the completed application form and the Terms & Conditions for Maximum Demand Tariff from the applicant, we will arrange for an inspection of the electrical installation to check if a Maximum Demand Meter can be installed. The account will then be charged under Maximum Demand Tariff after the Maximum Demand Meter is installed upon satisfactory inspection.

Regular Review and Load Management

As the circumstances may change from time to time, customers should regularly review and decide whether the Maximum Demand Tariff is still beneficial for them. Based on the information (kVA and kWh values) available from the monthly electricity bills for the Maximum Demand Tariff, customers can easily compare the amount of electricity charge under the Maximum Demand Tariff with that of Non-Residential Tariff (please refer to the examples for detailed calculation). Customers are also recommended managing their electrical loads effectively so that they can maximise the benefits of the Maximum Demand Tariff for their installations.

Please contact our Enquiry Office at 2887 3455 if you have any query about the Maximum Demand Tariff.