Introduction

There are three types of tariff:

Domestic Tariff

Commercial, Industrial & Miscellaneous Tariff

Maximum Demand Tariff

For details of the tariff structure, please refer to our tariff tables.

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 Commercial, Industrial & Miscellaneous 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 Commercial and Industrial Customers.

2.The minimum average monthly consumption should exceed 25,000 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.

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

Suppose the demand of an installation in a particular 30-minute interval is as follows:
1000 kVA in the first minute,
200 kVA in the following 20 minutes and
500 kVA in the final 9 minutes.

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 Commercial, Industrial & Miscellaneous Tariff

 Example 1

 
Example 2

 

 

Examples of Electricity Bill based on Low Voltage Tariff

 

Examples of Electricity Bill based on Low Voltage Tariff

Example 1

 

Given: Maximum Demand of the Month = 380kVA
           Energy Consumption of the Month = 120,000kWh


Demand Charge :     First 380 kVA at $43.10 (Per kVA) = $16,378
                               Additional  0 kVA at $42.10 (Per kVA) = $0
Total Demand Charge = $16,378


Energy Charge:     First 380 x 200 kWh at $1.131 (Net Rate) = $85,956
                            Additional  44,000 kWh at $1.073 (Net Rate) = $47,212
                            Rebate  120,000 kWh at - $0.001 (RRR Rebate)* = - $120
Total Energy Charge = $133,048


Bill by Maximum Demand Tariff = Demand Charge ($16,378) + Energy Charge ($133,048) = $149,426

Bill by Commercial, Industrial & Miscellaneous Tariff =1,500 x $1.207 + (120,000 - 1,500) x $1.30 - 120,000 x $0.001* = $155,740.5


Savings under Maximum Demand Tariff = $6,314.5

* Rate Reduction Reserve (RRR) Rebate
   A Rate Reduction Reserve Rebate of 0.1 cents per unit will be provided to the customer starting from 1st January
   2010 to refund the interest on the Tariff Stabilisation Fund. The Rebate may cease any time when the Rate
   Reduction Reserve is depleted.

 

Example 2

Given: Maximum Demand of the Month = 550kVA
           Energy Consumption of the Month = 120,000kWh


Demand Charge :     First 400 kVA at $43.10 (Per kVA) = $17,240
                               Additional  150 kVA at $42.10 (Per kVA) = $6,315
Total Demand Charge = $23,555


Energy Charge:     First 550 x 200 kWh at $1.131 (Net Rate) = $124,410
                            Additional 10,000 kWh at $1.073 (Net Rate) = $10,730
                            Rebate  120,000 kWh at - $0.001 (RRR Rebate)* = - $120
Total Energy Charge = $135,020


Bill by Maximum Demand Tariff = Demand Charge ($23,555) + Energy Charge ($135,020) = $158,575

Bill by Commercial, Industrial & Miscellaneous Tariff =1,500 x $1.207 + (120,000 - 1,500) x $1.30 - 120,000 x $0.001* = $155,740.5


Extra amount under Maximum Demand Tariff = $2,834.5

* Rate Reduction Reserve (RRR) Rebate
   A Rate Reduction Reserve Rebate of 0.1 cents per unit will be provided to the customer starting from 1st January
   2010 to refund the interest on the Tariff Stabilisation Fund. The Rebate may cease any time when the Rate
   Reduction Reserve is depleted.
       
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 to 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 Commercial, Industrial & Miscellaneous Tariff (please refer to the examples for detailed calculation). Customers are also recommended to manage 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.