Malaysia’s Energy Bill Calculation Considers the Lagging Power Factor Penalty
Sarawak Electricity Supply Corporation (SESCO) tariff rates and computation of electric energy shows a strict consideration of the lagging power factor at the demand side, whether it is commercial, residential, or industrial, in the electricity bill. (http://www.sesco.com.my/sesco/english/intransmission.html). Thus, the billing statement also shows the KVar-hour that was consumed by the end-user. (http://www.sesco.com.my/sesco/image/billextract.JPG)
The computation of the Lagging Power Factor Charge is given by the following formula;
LPF charge (LPFC) will be imposed where LPF is below 0.85.
LPF is between 0.85 and 0.75 :
[(0.85 - LPF) x 1.5 x Consumed Amount(RM)]LPF is 0.75 and below :
[ (0.85 - 0.75) x 1.5 x Consumed Amount(RM)] + [(0.75 - LPF) x 3 x Consumed Amount(RM)]
I don’t know how the formula was exactly derived but I’m quite sure that it has considered the factors that are directly affected by a lower power factor. A lower power factor induces line losses in the transmission and distribution lines, voltage drop, and reduced equipment capacity in the system. The imposition of penalty is, thus, justified. Examples of equipments that causes a lagging power factor are Fluorescent Lamp and Motors (electric fan, air condition, washing machine has motor). The distribution utility used to install power capacitors, at an optimal level, to compensate such negative impact of lagging power factor.
Power factor can be improved at the demand side by installing a capacitor. There are lots of capacitor that are designed for these purpose are already available in the market.
While imposing penalty for a lower power factor, it is quite ironic that they don’t give incentives to those who have a leading (opposite of lagging) power factor or within the allowed range. In their electricity bill calculator, http://www.sesco.com.my/sesco/english/metercalc5.htm, a negative KVarh reading shows a “Not Applicable (N/A)” charge. A leading power factor, if not excessive, is very much beneficial in the transmission and distribution of power. It can reduce losses, improve voltage profile and maximize the system capacity.
In the Philippines, the end-user receives benefits if there power factor is within the allowable level - 85% and up, while some are making business by just supplying KVar either from power capacitor or synchronous condenser to the transmission system. On the other hand, the lagging power factor penalty is only imposed to large industrial costumers.
Sarawak Electricity Supply Corporation (SESCO) is responsible for the generation, transmission and distribution of electricity in the State of Sarawak, Malaysia.
Filed in: Computations and Methodologies, Distribution Utilities
Local date: March, 2010
