How to Read an Industrial PLN Electricity Bill, Line by Line

An industrial electricity bill is far more complex than a household one. Several kinds of usage are charged at different rates, some costs stay fixed even when machines are off, and some appear only because of how machines draw power. Many plants look only at the total, yet the savings are hidden in the individual lines.

This article covers the common components of an industrial PLN electricity bill. Exact details and rates vary by tariff group and prevailing rules, so always check against your own bill.

Demand charge

The demand charge is based on connected or contracted power (kVA), not on usage. It stays roughly the same every month. A contract far above your real peak load means paying for capacity you never use. A contract that is too tight means the plant cannot add machines.

Judging whether your contracted power is right requires continuously recorded peak load data, not estimates.

LWBP and WBP kWh

Industrial customers are generally charged different rates for two time periods:

• LWBP (off-peak), most hours of the day.
• WBP (peak), typically late afternoon to evening, around 17:00 to 22:00. The WBP rate is higher than LWBP.

Because of this difference, when electricity is used matters as much as how much. Shifting flexible load out of WBP is one of the fastest savings, covered in full in cutting electricity cost during WBP peak hours.

Excess kVArh

This line appears when the monthly average power factor falls below 0.85. kVArh above the limit carries an extra charge. Causes and fixes are covered in our article on kVArh charges. If this line is on your bill, it is usually one of the quickest costs to eliminate.

Minimum charge

For certain groups, PLN sets a minimum usage calculated from minimum operating hours multiplied by connected power. If monthly use is below that threshold, the minimum charge is billed instead. This matters for facilities using far less than their contracted power, such as a plant running fewer shifts.

Taxes and other charges

The bill also includes the street lighting tax (PPJ), set by local government, so it differs between regions. Check any other lines that may apply to your tariff group.

Turning the bill into a list of actions

Bill line	Question to answer	Data needed
Demand charge	Does contracted power match the real peak load?	Daily peak load over time
WBP kWh	Which loads run during WBP, and can they move?	Hourly usage per panel
LWBP kWh	Are loads running without need, for example at night?	Usage outside operating hours
kVArh	Which panels have low power factor, and when?	Power factor per panel

The table shows one thing: the monthly bill tells you how much, but only hourly, per-panel data tells you why.

Example: tracing a bill that went up

Suppose this month's bill rose noticeably compared with last month, while production stayed about the same. A sensible order of investigation:

1. Compare line by line, not just the total. Did WBP kWh rise, did LWBP kWh rise, or did a new kVArh line appear?
2. If WBP kWh rose, look for loads that started running between 17:00 and 22:00. The cause is often a shift schedule change or a machine moved to the afternoon.
3. If LWBP kWh rose, check usage at night and on weekends. Loads someone forgot to switch off usually show up here.
4. If kVArh appeared, check the capacitor bank and power factor per panel.

A 30-minute monthly routine

Once hourly data is available, reviewing the bill no longer needs to be a big project. Set aside 30 minutes each month: match total kWh against your own meters, look at the WBP share, check power factor, and note one action for next month. This small habit stops bill increases from running for months before anyone asks why.

Frequently asked questions

When does WBP apply?

Typically around 17:00 to 22:00, but confirm with the terms for your tariff group.

Can the demand charge be reduced?

Yes, if data shows the real peak is far below contracted power. A reduction is requested from PLN, so make sure you have enough data to avoid running short when production is high.

Why did the bill rise when production did not?

Common causes are load shifting into WBP hours, loads running outside working hours, or new excess kVArh. Hourly data helps find which.

Reading the bill with InEnergy

InEnergy records hourly usage from every energy meter, separates WBP and LWBP periods, monitors power factor, and estimates cost from the tariff you enter. The PLN bill can then be checked against your own data every month, and the cause of any increase traced to a specific panel and hour. The meters can be IncludeBox Energy Meters or power meters already on site.