TNB ToU for Factories and Warehouses: Peak Hours, Rates, How to Switch and When It Saves Money

Key Takeaways

• TNB ToU (Time of Use) is an optional tariff that charges less for electricity used off-peak. Peak is 2pm to 10pm, Monday to Friday. Every other hour, all of Saturday and Sunday, and 15 selected public holidays are off-peak.
• For business accounts, the ToU energy charge is 1.49 sen/kWh above the General tariff at peak and 2.60 sen/kWh below it off-peak, on low, medium and high voltage alike.
• A low voltage factory or warehouse saves on ToU as long as less than about 64% of its units fall in the peak window. Round-the-clock, single day shift and most two-shift operations pass that test.
• On medium and high voltage, ToU charges maximum demand only on the peak recorded between 2pm and 10pm on weekdays, but at a higher rate per kW. It pays only if the plant keeps its heaviest load out of that window.
• Apply through the myTNB app or portal, or at a Kedai Tenaga. Switching costs RM10 in stamp duty and takes effect within five working days with an activated smart meter. You can go back to the General tariff for another RM10.

What is TNB ToU? It is Tenaga Nasional Berhad's Time of Use tariff: electricity costs more from 2pm to 10pm on weekdays and less at all other times. It is optional. A factory or warehouse that runs at night, at weekends or round the clock usually pays less on it, while a plant whose heaviest load sits in the weekday afternoon and evening can pay more. All rates in this guide are from TNB's tariff schedule effective 1 July 2025, as shown on myTNB in November 2026.

When are TNB ToU peak and off-peak hours?

TNB uses two time zones (TNB):

Day	Peak	Off-peak
Monday to Friday	2pm to 10pm	10pm to 2pm the next day
Saturday and Sunday	None	All 24 hours
15 selected public holidays	None	All 24 hours

A normal week therefore has 40 peak hours and 128 off-peak hours. Saturday is off-peak all day, which helps factories that work a half day or a full shift on Saturdays. TNB's statement of 2 October 2026 still describes the holidays as "selected", so confirm the list with TNB CareLine (1300-88-5454) before you plan a production run around a particular holiday.

Who can choose ToU?

• Non-Domestic Low Voltage (the old Tariff B and Tariff D): ToU was extended to these accounts from 1 July 2025 for premises with a smart meter. TNB said the scheme is open to all customers and that accounts without an activated smart meter go through a meter upgrade first (The Star). Bernama reported that customers with current transformer operated meters or remote meter reading systems can also take it up (The Sun, via TNB).
• Non-Domestic Medium Voltage and High Voltage (the old C1, C2, E1, E2, E3 and related tariffs): each voltage has a General and a ToU tariff. Accounts that were already on the old peak and off-peak tariffs, such as C2, E2 and F2, moved to ToU automatically (TNB letter, 21 August 2025).

TNB says about 217,000 customers switched to ToU between July 2025 and July 2026.

TNB ToU rates for factories and warehouses

Tariff	Energy, General	Energy, ToU peak	Energy, ToU off-peak	Capacity and network	Retail
Low Voltage	27.03 sen/kWh	28.52 sen/kWh	24.43 sen/kWh	8.83 + 14.82 sen/kWh on both tariffs	RM20 a month
Medium Voltage	29.83 sen/kWh	31.32 sen/kWh	27.23 sen/kWh	General RM89.27 per kW of MD; ToU RM97.06 per kW of peak MD	RM200 a month
High Voltage	43.03 sen/kWh	44.52 sen/kWh	40.43 sen/kWh	General RM31.21 per kW of MD; ToU RM44.82 per kW of peak MD	RM250 a month

The medium and high voltage figures add TNB's two per kW charges together: RM29.43 + RM59.84 (MV General), RM30.19 + RM66.87 (MV ToU), RM16.68 + RM14.53 (HV General) and RM21.76 + RM23.06 (HV ToU).

Three points decide the maths:

1. The energy gap is the same on every voltage. ToU peak is 1.49 sen/kWh above General, and ToU off-peak is 2.60 sen/kWh below it.
2. AFA does not change the comparison. TNB's bill formula multiplies the Automatic Fuel Adjustment by total kWh, so it costs the same per unit at any hour. The 1.6% Renewable Energy Fund (KWTBB) is charged on every non-domestic bill either way.
3. On medium and high voltage ToU, maximum demand recorded off-peak is not charged. Only the highest half-hour demand between 2pm and 10pm on weekdays counts, at a higher rate per kW.

The full tariff, the maximum demand rules and the power factor surcharge are explained in our TNB tariff 2026 guide for factories. This guide deals only with the ToU decision.

Is ToU cheaper for a low voltage factory or warehouse?

On low voltage, the capacity and network charges are per kWh and identical on both tariffs, so only the energy charge changes. If a share p of your units falls in peak hours, ToU costs 24.43 + (4.09 × p) sen per kWh against 27.03 sen on General. The two are equal when p is 2.60 ÷ 4.09, about 63.6%.

In plain terms: a low voltage account saves on ToU whenever less than about 64% of its electricity is used between 2pm and 10pm on weekdays.

What common shift patterns save

Operating pattern (even load while running)	Share of kWh in peak	Saving per kWh on ToU	Saving per 10,000 kWh
Round the clock, seven days	about 24%	1.62 sen	RM161.84
One shift, 8am to 5pm, Monday to Friday	about 33%	1.25 sen	RM125.03
Two shifts, 6am to 10pm, Monday to Friday	50%	0.555 sen	RM55.50
One shift, 2pm to 10pm, Monday to Friday	100%	1.49 sen more	RM149.00 more

Real buildings also draw power when nobody is working: cold rooms, compressors, security lighting and servers. That base load falls mostly in off-peak hours and pulls the peak share down further.

Worked example: a cold room warehouse on low voltage

Assume a warehouse with cold rooms uses 30,000 kWh a month at a steady rate, day and night, so about 24% of its units (7,200 kWh) fall in peak hours.

Energy charge	General	ToU
Peak, 7,200 kWh	7,200 × 27.03 sen = RM1,946.16	7,200 × 28.52 sen = RM2,053.44
Off-peak, 22,800 kWh	22,800 × 27.03 sen = RM6,162.84	22,800 × 24.43 sen = RM5,570.04
Total energy charge	RM8,109.00	RM7,623.48

The ToU account pays RM485.52 less a month, about RM5,826 a year, before KWTBB. Capacity, network, AFA and the RM20 retail charge are the same on both tariffs.

Medium and high voltage: why maximum demand decides

On Medium Voltage General you pay RM89.27 for every kW of the month's maximum demand (MD), whenever it happens. On Medium Voltage ToU you pay RM97.06 per kW, but only on the MD recorded in peak hours. That means:

• If your peak hour MD equals your overall MD, ToU adds RM7.79 per kW a month. On 500 kW that is RM3,895, which the cheaper off-peak energy has to recover first.
• ToU lowers the demand charge only when your peak hour MD is below about 92% of your overall MD (89.27 ÷ 97.06).
• On high voltage the gap is wider: RM44.82 per kW of peak MD on ToU against RM31.21 on General, so the peak hour MD has to be below about 70% of the overall MD before the demand charge falls.

Worked example: a medium voltage factory

Assume a factory uses 150,000 kWh a month with a maximum demand of 500 kW.

Charge	MV General	MV ToU, nothing moved (45% of kWh in peak, peak MD 500 kW)	MV ToU, heavy loads moved (35% of kWh in peak, peak MD 400 kW)
Energy	RM44,745.00	RM43,605.75	RM42,992.25
Capacity and network	RM44,635.00	RM48,530.00	RM38,824.00
Retail	RM200.00	RM200.00	RM200.00
Total before AFA and KWTBB	RM89,580.00	RM92,335.75	RM82,016.25

In the third column the factory still reaches 500 kW, but at night, so its General bill would not change. Moving the load is what creates the saving: the same plant pays RM2,755.75 more on ToU if nothing moves, and RM7,563.75 less if it moves 100 kW of demand and a tenth of its units out of the weekday 2pm to 10pm window.

A quick test for MV and HV accounts

1. Take 12 months of bills: kWh, MD and, if the account is already on ToU, peak kWh and peak MD.
2. Energy gain in RM = kWh × (2.60 - 4.09 × peak share) ÷ 100.
3. Extra demand charge in RM = (ToU rate × peak hour MD) - (General rate × overall MD).
4. If the energy gain is larger than the extra demand charge, ToU pays.

The bill calculator on myTNB also accepts a peak percentage and an MD figure for the ToU tariffs.

How to switch a factory or warehouse to TNB ToU

1. Read your bills. Note the tariff category, monthly kWh, MD (for MV and HV) and the meter type.
2. Estimate your peak share. Smart meter accounts can see time-based consumption in the myTNB app. Without that data, work it out from your shift times, as in the table above.
3. Apply. TNB takes ToU applications through the Time-of-Use (ToU) Application service in the myTNB app and portal, at Kedai Tenaga counters, and with help from TNB CareLine (TNB). TNB described the paper form as two pages, downloadable from the ToU section of mytnb.com.my/tariff (TNB letter).
4. Pay RM10 stamp duty. Switching amends your electricity supply contract, and stamp duty applies to every contract amendment.
5. Wait for activation. With an activated smart meter, ToU takes effect within five working days. Without one, allow up to two months for processing and the meter upgrade (The Star).
6. Check the first ToU bill. It should show the new tariff category, with kWh split into peak and off-peak.

Item	What to expect
Cost to switch	RM10 stamp duty
Time, smart meter already active	Within 5 working days
Time, meter needs upgrading	Up to 2 months
Switching back to General	Allowed, with another RM10 stamp duty
Where to apply	myTNB app or portal, or Kedai Tenaga

Tenants: whose name is the TNB account in?

TNB says the scheme is open to all registered account holders, including tenants, who have to agree with the property owner on whose name the account is under. Many rented factories keep the TNB account in the landlord's name, so the landlord may have to sign the application. Settle this in the tenancy agreement before you plan night shifts around ToU, and agree what happens to the tariff when you move out.

Which factory and warehouse operations gain from ToU?

TNB's own examples for businesses are water pumping into storage, overnight fleet charging and moving energy intensive work into off-peak hours where it is practical. In factories and warehouses that usually means:

• Cold rooms and cold storage running round the clock, where about three quarters of the units fall off-peak.
• Night shifts and weekend production. Saturday is off-peak all day.
• Forklift and EV fleet charging after 10pm.
• Compressed air, chilled water or water tanks that can be charged or filled before 2pm and drawn down in the afternoon.
• Batch processes such as ovens, kilns, mixers or heat treatment that can start after 10pm.

ToU tends not to pay for a single 2pm to 10pm shift, for work concentrated in the late afternoon and evening, or for MV and HV plants whose maximum demand is set in the afternoon and cannot move.

Common mistakes

• Assuming ToU is always cheaper. On MV and HV it can raise the bill.
• Starting every machine together at 2pm or at the start of an afternoon shift, which sets the month's peak MD in one half hour.
• Planning a holiday production run without checking which public holidays TNB counts as off-peak.
• Signing a lease without checking whose name the TNB account is in.

How is ToU for a factory different from ToU at home?

	Home (Domestic ToU)	Factory or warehouse, low voltage	Factory, medium or high voltage
Energy rate, peak and off-peak	28.52 and 24.43 sen up to 1,500 kWh; 38.52 and 34.43 sen above	28.52 and 24.43 sen on every kWh	MV 31.32 and 27.23 sen; HV 44.52 and 40.43 sen
Capacity and network	Per kWh	Per kWh	Per kW of peak hour MD
Bill protection to 31 December 2026	AFA, retail charge and service tax waived at 800 kWh a month and below	Not available	Not available

The domestic rates are from The Star. The 800 kWh protection covers domestic customers only, from September to 31 December 2026 (TNB).

Buying or renting a factory: check the tariff before you sign

• Ask for 12 months of TNB bills and read the tariff line, for example "Non-Domestic Low Voltage ToU" or "Non-Domestic Medium Voltage General".
• Check the supply voltage, because it decides which ToU test above applies. The factory power calculator turns your machine list into amps.
• For a cold store or a round-the-clock plant, compare cold storage warehouse specs and filter units by power on find a factory by specs.
• Jason Low's partner site also explains how to estimate a unit's TNB bill before you sign.

This guide explains TNB's published tariffs and is not financial advice. Confirm current rates and terms with TNB before you switch.

Frequently Asked Questions

What is TNB ToU?

TNB ToU (Time of Use) is an optional electricity tariff with a higher rate from 2pm to 10pm on weekdays and a lower rate at all other times, including all of Saturday, Sunday and 15 selected public holidays. For business accounts, the off-peak energy rate is 2.60 sen/kWh below the General tariff and the peak rate is 1.49 sen/kWh above it. It suits users who can run their heaviest loads outside the weekday afternoon and evening.

What time is TNB ToU peak hour?

Peak is 2pm to 10pm, Monday to Friday. Off-peak runs from 10pm to 2pm the next day on weekdays, and all 24 hours on Saturday, Sunday and the selected public holidays TNB names.

Is TNB ToU worth it for a factory?

On low voltage it is, whenever less than about 64% of your units are used between 2pm and 10pm on weekdays, which covers round-the-clock, single day shift and most two-shift factories. On medium and high voltage it depends on maximum demand: ToU charges a higher rate per kW on the peak hour MD, so it pays only if you keep your heaviest load out of the peak window.

How do I apply for TNB ToU?

Apply through the Time-of-Use (ToU) Application service in the myTNB app or portal, or at a Kedai Tenaga. You pay RM10 in stamp duty. ToU starts within five working days if your smart meter is already active, or within about two months if TNB has to upgrade the meter.

Can I switch back from ToU to the General tariff?

Yes. TNB lets customers revert to the General tariff if ToU does not suit them, with another RM10 stamp duty for the contract change. Wait for at least one full ToU bill before you decide, because it shows your real peak and off-peak split.

Do I need a smart meter for TNB ToU?

For low voltage accounts, ToU runs on a smart meter, and TNB upgrades the meter for accounts that apply without an activated one, which can take up to two months. Current transformer operated meters and remote meter reading systems were also reported as eligible. Medium and high voltage accounts choose between the General and ToU tariffs for their voltage.

Is maximum demand charged at night on ToU?

No. On medium and high voltage ToU, TNB does not charge maximum demand recorded in off-peak hours. Only the highest demand between 2pm and 10pm on weekdays sets the capacity and network charge, at RM97.06 per kW on medium voltage and RM44.82 per kW on high voltage.

Can a tenant apply for TNB ToU?

Yes. TNB says the scheme is open to all registered account holders, including tenants, who have to agree with the owner on whose name the account is under. If the factory's account is in the landlord's name, the landlord has to be part of the application.

FactoryHub is dedicated to helping every client find the right factory or warehouse. For a unit with the power, supply voltage and tariff history your operation needs, talk to Peter Tan (REN 12771) at 016-666 6872 or Jason Low (PEA 1478) at 012-288 1834.