RP4 tariff analysis · Peninsular Malaysia

Which tariff should this site be on?

Load a month of interval meter readings. This prices them under Medium Voltage General and Medium Voltage Time-of-Use, and tells you which one this site should be on and what the difference is worth. Everything runs in this page — nothing is uploaded anywhere.

running self-tests…

01 — Data

Interval readings

Drop a CSV here, or

Needs a timestamp column and a kWh column — headers are detected case-insensitively (timestamp/datetime/date_time/time/reading_time and kwh/consumption/energy/usage). Optional kw and pf columns are used if present. 15-minute, 30-minute and hourly data all work.

02 — The answer

Recommendation

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Month by month

03 — The working

Bill build-up, both tariffs

Every line, so it can be checked against a real bill.

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04 — The picture

Where the billed peak falls

Shaded bands are the weekday 14:00–22:00 peak window. Time-of-Use bills demand only inside them.

Demand Peak window General billed peak Time-of-Use billed peak

05 — Cap explorer

What holding a demand cap is worth

Modelled as a load shift: billed demand falls, kilowatt-hours do not. No energy saving is claimed.

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06 — Rates

Tariff schedule and assumptions

RP4, effective 1 July 2025 – 31 December 2027. Every rate is an input; correcting one recomputes the page.

These figures agree across independent published sources. Medium Voltage General at 29.83 sen/kWh; Time-of-Use at 31.32 / 27.23 sen/kWh peak / off-peak; the two demand pairs; and the weekday 14:00–22:00 window with off-peak demand not charged. The retail charge is the exception — still a placeholder, though at RM200 against a six-figure bill it changes nothing. Verify against the gazetted Suruhanjaya Tenaga schedule or a real bill before quoting a costed figure, and correct anything below if it differs.

Rates

Peak window confirmed

Monday–Friday 14:00–22:00. Off-peak is weekdays 22:00–14:00 plus all Saturday and Sunday. General bills the highest 30-minute average anywhere in the month; Time-of-Use bills only the highest inside the window — demand occurring off-peak is not charged. That asymmetry is the entire arbitrage.

Off by default. Sources do not state how RP4 treats public holidays in the peak window, and a factory running through Hari Raya could set a peak this gets wrong. Resolve before the meeting.

Definitions and caveats

  • Maximum demand = kWh in a 30-minute interval × 2.
  • KWTBB renewable levy applied at 1.6% of the bill before the levy. verify — exemptions exist
  • AFA applies to all kWh and is reset monthly. It has moved more than 7.5 sen/kWh within 2026, so it is an input, not a constant.
  • Power factor surcharge is computed only when the CSV carries a PF column: 1.5% per 0.01 below 0.85, and 3% per 0.01 below 0.75.
  • Timestamps are read as Asia/Kuala_Lumpur wall-clock. The page never converts to UTC, which would shift the peak window by eight hours.