01Current TNB Commercial Rate: 45.62 sen/kWh
The 45.62 sen/kWh figure represents the blended commercial energy tariff effective from July 1, 2025 under RP4. However, for Medium Voltage industrial users — the majority of Malaysian factories with demand above 1 MW — the actual cost structure is far more complex and significantly higher during peak hours.
Under RP4, TNB has unbundled the tariff into three distinct cost components. Understanding each component is critical to identifying where solar provides the greatest financial impact.
| Tariff Component | Rate | Description |
|---|---|---|
| Capacity Charge (Generation) | 4.55 sen/kWh | Cost to maintain power plant capacity; fixed per unit consumed |
| Network Charge (Transmission + Distribution) | 12.85 sen/kWh | Cost of grid infrastructure — cables, substations, transformers |
| Energy Charge (Fuel + Variable O&M) | 28.22 sen/kWh | Actual fuel cost (coal/gas/LNG); subject to ICPT adjustments |
| ICPT Surcharge (H1 2026) | 3.70 sen/kWh | Fuel cost pass-through; reviewed every 6 months |
| Blended Total (Commercial) | 45.62 sen/kWh | Effective headline rate for commercial users |
Solar impact on unbundled tariffs: Onsite solar generation directly reduces the Energy Charge and ICPT components (fuel-linked). The Capacity Charge and Network Charge are partially retained since you still need grid connection. MD charges (Maximum Demand) are calculated separately from these per-kWh components.
02Medium Voltage Tariff Categories (E1, E2, E3)
TNB's industrial tariffs are structured by voltage level and consumption pattern. Most Malaysian factories with demand between 1–10 MW fall under the Medium Voltage (MV) categories. Understanding which category you are on determines your MD charge exposure.
| Tariff | Typical User | MD Charge (RM/kW) | Peak Rate (sen/kWh) | Off-Peak Rate |
|---|---|---|---|---|
| E1 (General MV) | SME factories, light industrial, cold storage | RM 45.10 | 36.00 sen | — |
| E2 (Peak/Off-Peak MV) | Medium-large factories with >1MW demand | RM 89.27 | 52.00 sen | 28.60 |
| E3 (High Voltage) | Large industrial (steel, cement, semiconductor) | RM 37.00 | 30.80 sen | 22.40 |
Critical: Tariff E2 has the highest MD charge at RM89.27/kW — 98% higher than E3 and 98% higher than E1. If your factory is on E2 (most factories above 1MW demand are), Maximum Demand reduction is your single largest cost-reduction opportunity.
03Maximum Demand Explained: The RM89.27/kW Penalty
Maximum Demand (MD) is the single most misunderstood item on a Malaysian industrial electricity bill. It is not based on your total consumption — it is based on your peak consumption in any 30-minute window during the billing month.
How TNB Measures Maximum Demand
TNB installs a peak-demand meter that continuously samples your power draw. Every 30 minutes, it records the average kW consumption for that interval. The highest single 30-minute average across the entire month becomes your “Maximum Demand” — and you are billed at RM89.27 for every kW of that peak, for the entire month.
Common MD Spike Causes in Malaysian Factories
04How Solar Reduces Maximum Demand: 500 kWp Example
A rooftop solar system's peak generation occurs between 10am and 2pm — exactly when most Malaysian factories hit their highest demand periods. The instantaneous solar power output (measured in kW) directly offsets the grid demand recorded by TNB's MD meter.
Daily Load Profile: Before vs. After Solar
Typical 500kW factory on Tariff E2 (8am–6pm operation)
MD Savings Calculation: 500 kWp Solar System
| Cost Component | Before Solar | After Solar | Monthly Saving |
|---|---|---|---|
| MD Charge (E2) | RM 44,635 | RM 8,927–17,854 | RM 26,781–35,708 |
| Peak Energy (52 sen × 55,000 kWh) | RM 28,600 | RM 14,300 | RM 14,300 |
| Off-Peak Energy (28.6 sen × 50,000 kWh) | RM 14,300 | RM 14,300 | — |
| ICPT Surcharge (3.70 sen) | RM 3,885 | RM 1,943 | RM 1,943 |
| Service Tax (8%) | RM 7,313 | RM 3,160 | RM 4,153 |
| Total Monthly Savings | RM 98,733 | RM 42,630 | RM 47,177–56,104 |
05Peak Shaving with Battery Storage (LFP BESS)
For factories where MD spikes occur outside solar hours — early morning shift start-ups, night shifts, or on overcast days — Lithium Iron Phosphate (LFP) Battery Energy Storage Systems provide deterministic peak shaving. Unlike solar, a battery can guarantee a maximum demand ceiling regardless of weather.
Solar-Only Peak Shaving
Effective during daylight hours (8am–5pm). Malaysia's consistently high irradiance means solar-only achieves 60–80% of maximum theoretical MD reduction.
Solar + LFP Battery
Charges from solar during midday; discharges to shave peaks at any hour. Guarantees a hard MD ceiling, providing certainty to finance teams modeling utility costs.
| MD Reduction Target | BESS Power (kW) | BESS Capacity (kWh) | Indicative Cost | MD Savings/mo |
|---|---|---|---|---|
| 100 kW reduction | 100 kW | 200 kWh | RM 350,000 | RM 8,927 |
| 200 kW reduction | 200 kW | 400 kWh | RM 680,000 | RM 17,854 |
| 300 kW reduction | 300 kW | 600 kWh | RM 990,000 | RM 26,781 |
| 500 kW reduction | 500 kW | 1,000 kWh | RM 1,600,000 | RM 44,635 |
Run an MD savings estimate
Model the first-pass RM value of reducing your recorded maximum demand with BESS and solar.
Cold storage BESS
Peak-shaving and backup-cooling strategy for refrigerated warehouses and logistics sites.
Electronics BESS
Cleanroom, EMS and semiconductor load-profile strategy for MD control and resilience.
06ICPT Surcharge: The Hidden Cost That Solar Eliminates
The Imbalance Cost Pass-Through (ICPT) is a surcharge mechanism introduced by the Energy Commission that allows TNB to pass fuel cost fluctuations — primarily coal and natural gas — directly to consumers. As of H1 2026, the commercial ICPT surcharge is 3.70 sen/kWh, adding RM3,700 per 100,000 kWh consumed.
| Period | ICPT Rate (sen/kWh) | Annualized Cost (per 1 GWh) |
|---|---|---|
| H2 2024 | 2.00 sen | RM 20,000 |
| H1 2025 | 3.00 sen | RM 30,000 |
| H2 2025 | 3.50 sen | RM 35,000 |
| H1 2026 ← Current | 3.70 sen | RM 37,000 |
Solar energy has no fuel cost — it is immune to ICPT increases. Every kWh generated by your rooftop solar system displaces one kWh from the grid at the full tariff rate including ICPT. As global coal and LNG prices remain volatile, solar provides a hedge against future ICPT surcharge escalation. If ICPT rises to 5.00 sen/kWh by 2027, your solar-displaced kWhs become proportionally more valuable.
“The MD charge is the silent killer of Malaysian factory profitability. We have audited over 200 industrial facilities, and in 78% of cases, the factory had never analyzed its 30-minute demand profile. When you see the chart, the opportunity for a 25–35% utility cost reduction through solar peak shaving becomes immediately obvious.”
07Frequently Asked Questions
What is TNB Maximum Demand (MD) and how is it calculated?
What is the TNB ICPT surcharge and will it increase in future?
How much does a 500 kWp solar system actually reduce my Maximum Demand?
What is the difference between Tariff E1, E2, and E3?
Do I need battery storage (BESS) for peak shaving, or can solar alone do it?
Can I check my historical Maximum Demand data before commissioning solar?
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