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Configure solarTNB Time of Use (TOU) Tariff Malaysia 2026: How Solar and BESS Fit
TNB MV ToU tariff charges 31.32 sen/kWh during peak and 27.23 sen/kWh off-peak — plus RM97.06/kW MD charge. Peak is 2pm–10pm on weekdays, so only the afternoon part of solar output earns the peak rate. This guide shows how to assess TOU with solar and BESS.
What Is TNB Time of Use (TOU) Tariff?
Time of Use tariff charges different kWh rates based on when you consume electricity — not just how much you consume. TNB offers TOU under the Medium Voltage Time of Use (MV ToU) tariff for non-domestic consumers. Instead of one flat rate all day, you pay more during peak hours when grid demand is high, and less during off-peak hours when the grid has surplus capacity.
Peak Hours
31.32 sen/kWh
2:00pm – 10:00pm (Monday–Friday)
8 hours/day on weekdays (2pm–10pm)
Off-Peak Hours
27.23 sen/kWh
10:00pm – 2:00pm on weekdays + all day Saturday, Sunday and 15 public holidays
Nights and mornings on weekdays, all day Saturday, Sunday and public holidays
24-Hour TOU Daily Pattern
Monday – Friday pattern. Saturday, Sunday and public holidays are fully off-peak.
MV ToU Rate Structure (2026)
MV ToU has three billing components: a Maximum Demand charge per kW, a peak kWh rate, and an off-peak kWh rate. Understanding all three is critical to evaluating whether MV ToU is right for your business.
| Component | MV General (Flat Rate) | MV ToU |
|---|---|---|
| MD Charge | RM 89.27/kW/mo | RM 97.06/kW/mo |
| Peak kWh Rate | 29.83 sen (flat) | 31.32 sen |
| Off-Peak kWh Rate | 29.83 sen (flat) | 27.23 sen |
| Solar kWh Value | 29.83 sen | about 28.42 sen (blended) |
| BESS Arbitrage Spread | N/A (flat rate) | 4.09 sen/kWh |
When does MV ToU beat MV General? It can beat MV General when enough consumption is off-peak to outweigh the higher MD charge; break-even depends on your kWh and MD, so model it with the calculator.
How Solar Fits a TOU Tariff
Solar panels generate maximum output between 9am and 4pm, while the TOU peak window runs from 2pm to 10pm, Monday to Friday. Only roughly 2pm–4pm of solar output overlaps the peak window; the morning output falls in off-peak. So afternoon solar kWh displace peak electricity at 31.32 sen, while morning solar kWh displace off-peak electricity at 27.23 sen.
Solar value is 15% higher at TOU peak vs off-peak
Peak-hour solar displaces 31.32 sen/kWh on MV ToU vs 29.83 sen/kWh on MV General flat, but morning solar displaces only 27.23 sen. Blended at the calculator's 29% peak / 71% off-peak split (2 of the 7 generating hours fall in the peak window), solar is worth about 28.42 sen/kWh, about 4.7% below the flat rate.
Solar Generation vs TOU Peak Window
Solar generation (yellow curve) overlaps the TOU peak hours (orange band) only in the afternoon. Afternoon solar kWh displace 31.32 sen peak electricity; morning solar kWh displace 27.23 sen off-peak electricity.
Peak Displacement
Solar generates 9am–4pm. Roughly 2pm–4pm of that output falls in the 2pm–10pm peak window and displaces peak electricity; the morning output falls in off-peak.
Savings Rate Depends on Timing
An afternoon solar kWh saves 31.32 sen (peak) versus 29.83 sen on the flat rate; a morning solar kWh saves 27.23 sen (off-peak).
MD Is Not Reliably Reduced
Solar alone does not reliably cut MD, because one cloudy half-hour can still set the month's MD. On MV ToU, each kW of MD is charged at RM97.06/month.
Interactive TOU Savings Calculator
Enter your consumption details to compare your bill on MV General flat rate vs MV ToU — with and without solar.
kWh / month
kW
kWp (set to 0 for no solar)
MV General Flat Rate Bill
RM 32,769
/month
MV ToU Bill (No Solar)
RM 34,356
/month
MV ToU Bill + Solar
RM 31,373
/month
Extra savings from TOU vs flat rate
Solar saves this much MORE on MV ToU vs MV General tariff
RM 0
Based on TNB MV ToU tariff 2026. Solar generation estimated at 3.5 peak sun hours/day (Trexon planning basis).
BESS for TOU Arbitrage: Charging Cheap, Discharging Expensive
Battery Energy Storage Systems unlock a second profit stream on TOU tariff: arbitrage. Charge your batteries during off-peak hours when electricity costs 27.23 sen/kWh. Discharge during peak hours when electricity costs 31.32 sen/kWh. The arbitrage spread is 4.09 sen per kWh per cycle.
BESS TOU Arbitrage Flow
Off-Peak
10pm – 2pm
27.23 sen/kWh
Charge BESS
Arbitrage value: 4.09 sen/kWh per cycle
Peak Hours
2pm – 10pm
31.32 sen/kWh
Discharge BESS
Monthly Arbitrage Value by BESS Size
| BESS Size | Monthly Arbitrage | Annual Arbitrage |
|---|---|---|
| 100 kWh | RM 123 | RM 1,493 |
| 300 kWh | RM 368 | RM 4,479 |
| 500 kWh | RM 614 | RM 7,464 |
| 1,000 kWh | RM 1,227 | RM 14,929 |
Based on 1 cycle/day, 4.09 sen/kWh arbitrage spread, 30-day month. Excludes BESS charge/discharge efficiency losses (~90%).
Arbitrage
Buy cheap off-peak, sell value during peak. 4.09 sen/kWh spread per daily cycle.
Peak Shaving
Discharge at demand peaks to lower your MD reading. On MV ToU, each kW saved = RM97.06/month.
Solar Buffer
Store excess midday solar. Release during the peak window (2pm–10pm), especially after solar output fades.
Should You Switch to MV ToU Tariff?
MV ToU is not automatically better than MV General. The answer depends on your consumption pattern, your MD, and whether you have — or plan to install — solar or BESS. Use this decision framework to assess your situation.
Switch to MV ToU if...
Your off-peak share is high enough
The cheap off-peak rate (27.23 sen) drives your average kWh cost below MV General's 29.83 sen flat rate, even after paying the higher MD charge.
You have or plan to install solar
Afternoon solar output (roughly 2pm–4pm) earns the peak rate (31.32 sen vs 29.83 sen flat), but morning output earns the off-peak rate (27.23 sen). Check your own load profile before switching.
You operate BESS for demand management
TOU arbitrage (4.09 sen/kWh spread) provides a direct revenue stream on top of demand charge savings. BESS payback is materially faster on MV ToU.
You run a night-shift operation
Night production (10pm–2pm on weekdays) runs entirely on off-peak rates, dramatically cutting your energy cost without changing operations.
Stay on MV General if...
You operate only during the weekday peak window (2pm–10pm)
If all consumption is during peak hours, MV ToU costs more per kWh AND charges an 8.7% higher MD rate — a double penalty.
Your MD is very high relative to kWh consumption
The MV ToU MD premium (RM97.06 vs RM89.27) adds RM7.79/kW/month. If your MD is 500kW, that is RM3,895/month extra — it takes a lot of kWh savings to offset this.
You have no plans for solar or BESS
Without solar or BESS, the only way to benefit from MV ToU is shifting consumption to off-peak hours. If you cannot shift loads, MV General is safer.
Critical: Run the numbers before switching
MV ToU MD charge (RM97.06/kW) is 8.7% higher than MV General (RM89.27/kW). For a 500kW MD site, this is an extra RM3,895/month in MD alone. Your off-peak kWh savings must exceed this MD premium to benefit from MV ToU. Use our calculator above to model your specific scenario.
How to Apply for TNB TOU Tariff
Apply to TNB for the tariff change and confirm the process, timeline and any charges with TNB. Note that TNB applies 8% service tax when a tariff change creates a billing period shorter than 28 days.
Request 3-Month Interval Data from TNB
Contact your local TNB Commercial office and request 30-minute interval consumption data for the past 3 months. This shows your actual peak vs off-peak split.
Analyse Your Peak / Off-Peak Split
Calculate what percentage of your monthly kWh falls in peak hours (2pm–10pm Mon–Fri) vs off-peak. Use the calculator above to model your potential savings.
Calculate Net Savings vs MV General
Compare your projected MV ToU bill (peak kWh savings minus the MD premium) against your current MV General bill. Ensure savings are positive before applying.
Submit Application to TNB
Submit a tariff change request at your TNB Commercial office or through the myTNB portal. Confirm any charges with TNB.
TNB Installs TOU Smart Meter
TNB will schedule a meter replacement appointment. The new TOU-capable smart meter records 30-minute interval data and enables accurate peak/off-peak billing. Confirm the installation timeline with TNB.
Let Trexon handle the TOU analysis for you
We request your TNB interval data, model your peak/off-peak split, and recommend the optimal tariff — as part of your free quote.
Frequently Asked Questions
Maximise Your TOU Tariff Savings with Solar + BESS
Trexon engineers will remotely analyse your TNB bills, calculate your peak/off-peak split, and prepare an initial solar + BESS design that maximises your MV ToU savings. Free quote, no commitment.
