Model your project savings and peak-demand reduction
Calculate ROITNB Maximum Demand Charge: How Malaysian Factories Can Reduce MD Charges
TNB maximum-demand charges are tariff-specific and can be a major hidden cost on a factory bill. Medium voltage customers should use the rate printed on their current bill (RM89.27/kW on MV General since 1 July 2025). Learn 5 practical strategies used by Malaysian manufacturers to cut maximum demand by 15–30%.
What Is TNB Maximum Demand (MD)?
Maximum Demand is the highest 30-minute average power draw recorded on your meter during the billing period. TNB charges you for this peak capacity reservation — regardless of whether you actually use it consistently.
Typical TNB Bill Breakdown — 500kW Factory
Illustrative MV General input only. Actual MD rate varies by tariff, voltage, billing schedule and power factor; verify the current bill.
30-Minute Windows
TNB averages your power draw every 30 minutes. The single highest 30-min reading each month becomes your MD.
One Spike = One Month
A single simultaneous machine startup sets your MD for 30 days — even if it never happens again that month.
Separate From kWh
MD charges are capacity reservation fees — you pay them regardless of actual energy consumed that month.
Interactive MD Cost Calculator
Enter your current Maximum Demand to see exactly what you are paying — and how much you can save.
Illustrative only — enter the MD rate shown on your current TNB bill
Example: model a 500kW factory using its current tariff bill
The annual result depends on the tariff-specific RM/kW rate and interval data. Treat any saving as a modeled scenario until the bill and load profile are checked.
5 Practical MD Reduction Strategies for Malaysian Factories
These strategies are ranked from lowest cost to highest ROI. Implement them in order for the fastest payback.
Load Staggering
Sequence machine startups over 5–10 minute intervals instead of simultaneous starts. One production line firing up all motors at once can spike your MD for the entire month. This is the highest-leverage, zero-cost intervention available to any factory.
Power Factor Correction
Install automatic capacitor banks at your main distribution board to bring power factor above 0.95. Poor PF inflates your apparent (kVA) demand and current, and TNB charges a separate power factor penalty below 0.85. The MD charge itself is based on kW, so PF correction mainly removes the penalty.
Variable Speed Drives (VSD/VFD)
Install VSD on your largest motor loads: HVAC fans, compressors, conveyor belts, and pumps. A VSD reduces motor startup inrush current from 6–8x rated to 1.5x rated, directly cutting your MD spike. VSD also save 20–40% on motor energy consumption.
Solar Peak Shaving
A rooftop solar system generates power during daylight hours (9am–4pm), offsetting your grid draw during production. But MD is set by the single highest 30-minute window in the month, so one cloudy half-hour can erase the reduction: solar alone does not reliably cut MD. Its main saving is on energy (kWh) charges; pair it with BESS to target MD.
BESS Peak Shaving
Battery Energy Storage Systems charge during off-peak hours (11pm–7am) at cheaper off-peak tariff rates and discharge during your peak demand window. Unlike solar, BESS works regardless of weather and can be programmed to target your specific MD spike times; response time is confirmed in the system design.
| Strategy | MD Saving | Cost | Payback |
|---|---|---|---|
| Load Staggering | 5–10% | RM0 | Immediate |
| Power Factor Correction | Penalty only | RM15K–40K | 12–24mo |
| VSD on Motors | 10–20% | RM5K–20K/motor | 18–36mo |
| Solar Peak Shaving | Not reliable alone | ~RM2,400/kWp | ~6.4yr |
| BESS Peak Shaving | 15–30% | RM80K–500K | Site-specific |
Before vs After: 24-Hour Factory Load Profile
This chart shows how solar + BESS peak shaving flattens a typical Selangor factory load curve. The red dotted line is the old MD peak. The green bars show the new reduced demand profile.
Solar peak shaving zone (8am–4pm): average demand reduced from 88% to 62% of installed capacity — a sustained 30% MD reduction during the critical billing window.
GITA Tax Treatment for BESS: 100% Allowance (Tier 1)
BESS is a GITA Asset Tier 1 item: an allowance of 100% of qualifying capex, set off against up to 70% of statutory income each year. Solar PV is Tier 2 (60%). Commission the system and submit the application to MGTC by 31 December 2026. Subject to MGTC verification; confirm the tax treatment with your adviser.
Check GITA eligibility
Confirm the applicable GITA Asset category, certification and application route with MGTC and your tax adviser
Offset 70% Income
Apply the ITA against up to 70% of your company statutory income each year until the allowance is fully utilised
Model the tax treatment
An allowance percentage is not a cash-cost reduction. Model utilisation, statutory income, tax rate and timing with your tax adviser.
Example: RM200,000 BESS investment
How Trexon Helps You Reduce MD
Trexon delivers an integrated solar + BESS + energy efficiency solution specifically engineered for maximum demand reduction at Malaysian factories.
MD Baseline Review
As part of your free quote, we review 12 months of TNB bills to identify your MD pattern, peak hours, and quick wins that need no capital.
Solar System Design
Rooftop solar sized to your daytime load, cutting energy (kWh) charges during your production hours.
BESS Peak Shaving
LFP battery systems with automatic demand limiting that targets your MD peak windows.
Power Factor Correction
Automatic capacitor banks that maintain PF above 0.95, eliminating power factor penalties and reducing kVA and losses.
Real-Time Monitoring
Live demand, solar output, and BESS state-of-charge — visible in the supplier's monitoring portal.
GITA Application Support
Our team can help prepare the evidence pack; MGTC and your tax adviser must confirm eligibility and the current application route.
Frequently Asked Questions
Ready to Cut Your MD Charges?
Get a free quote from Trexon. Send 12 months of TNB bills and we calculate your savings potential before any commitment.
