TNB Maximum Demand charges can consume 30-50% of your total electricity bill. Solar and battery storage (BESS) are the proven industrial strategy to shave demand peaks — reducing MD charges by 15-40% with 4-7 year payback.
40%
Max MD Reduction Achievable
RM89.27
Per kW/Month (TNB E2)
4-7yr
Payback with GITA
RM321K
Max Annual Savings (1.2MW)
Peak shaving is the strategy of reducing your highest power demand intervals to lower your TNB Maximum Demand (MD) charge. Your MD is not your average demand — it is the single highest 30-minute average power draw recorded in your billing period.
Even one production spike — multiple machines starting simultaneously, an air compressor surge, or a cooling system cycling — sets your Maximum Demand for the entire month. Every kilowatt of that peak costs you RM89.27 per month on your bill.
Peak shaving cuts that peak height. By generating your own power during high-demand intervals (solar) or discharging stored energy to offset grid draw (BESS), you reduce the number reported to TNB — and the charge that follows.
30-Minute Intervals
TNB measures your average power draw every 30 minutes, 24 hours a day, all month.
Highest Interval Wins
The single highest 30-minute average becomes your Maximum Demand for that billing cycle.
RM89.27/kW Charged
That one MD figure is multiplied by RM89.27 to produce your monthly demand charge — regardless of how low your demand is the rest of the month.
A single production surge — even for just 30 minutes — locks your MD charge for the full month at RM89.27/kW. Managing that one interval delivers massive financial return.
Enter your current Maximum Demand to see the financial impact
Annual MD Charge
RM 535,620
RM 44,635/month
Annual Savings
RM 133,905
RM 11,159/month
Reduced MD
125 kW
— 25%
New MD after reduction
375 kW
RM 33,476/month
Annual MD Cost by Factory Size
Based on TNB E2 tariff at RM89.27/kW/month (2026 rate)
Choose the right approach based on your load profile and budget
15-25%
MD Reduction
RM2.50-3.50/Wp
Cost
4-6 years
Payback
Lowest capex of the three options
Simplest installation and maintenance
Dual benefit: energy savings + MD reduction
Full GITA eligibility
Only reduces daytime peaks (9am-4pm)
No effect on morning startup or evening peaks
Dependent on weather and cloud cover
Best For
Factories with 10am-3pm peak demand and daytime-only operations
20-35%
MD Reduction
RM1,500-2,500/kWh
Cost
5-8 years
Payback
Shaves peaks at any time of day or night
Programmable demand limiting (automatic)
No weather dependency
Can also provide backup power
Higher capex than solar alone
Requires charging from grid (off-peak rates)
Battery degradation over 10-15 years
Best For
Factories with evening/morning peaks, shift-based operations, or critical power needs
25-40%
MD Reduction
RM3.50-5.50/Wp equiv.
Cost
4-7 years
Payback
Highest MD reduction of all approaches
Solar charges BESS during the day
BESS covers morning and evening peaks
Full GITA incentive on both components
Maximum ROI on combined investment
Highest total capex
More complex system integration
Larger roof/land footprint required
Best For
Most Malaysian factories — best long-term economics with GITA support
Step-by-step: what happens during daylight hours
Toggle to see how solar and BESS shave demand peaks
Solar generation is minimal (2-12%). Your factory startup draws heavily from the grid. This is often when the highest MD spikes occur. Solar alone cannot help here — this is where BESS matters.
Solar panels hit 60-90% output. As solar generation increases, it directly offsets your grid draw kW-for-kW. Your measured grid demand drops — reducing your potential MD reading in this window.
Solar is at maximum output (95-100%). If your factory peaks during this window, solar can shave 15-25% of that peak. On-site generation directly reduces the kW your TNB meter records.
Solar generation drops from 45% to near zero. As afternoon shifts continue, the MD-reduction benefit of solar fades. BESS can discharge during this window to extend peak shaving.
Solar generates nothing overnight. Evening shift changes, overnight operations, and early morning startups are entirely supplied by the grid. Only BESS can shave peaks during these hours.
Solar alone only reduces daytime grid demand. For factories with peaks outside daylight hours — which includes most Malaysian multi-shift operations — BESS is essential to capture the full 25-40% MD reduction potential.
Battery storage closes the gap solar cannot cover
During peak solar hours, surplus generation charges the BESS instead of being exported to the grid. The BESS stores this energy at near-zero marginal cost for use during demand peaks.
If solar generation is insufficient, BESS can charge from the TNB grid during off-peak hours (11pm-7am) at lower rates. This stored energy is then discharged during high-demand periods.
Modern BESS systems include demand-limiting controllers. When grid demand approaches your target MD threshold, the BESS automatically discharges to keep the 30-minute average below that ceiling — 24 hours a day, even during startup surges.
Every month, the BESS actively manages your demand profile. As your MD is capped below the previous month's spike, your TNB bill reflects the lower demand — consistently, reliably, automatically.
| Brand | Typical Size | Use Case | GITA |
|---|---|---|---|
| Tesla Megapack | 3.9 MWh | Utility & large industrial | |
| BYD Battery-Box | 200-500 kWh | Commercial & mid-industrial | |
| Sungrow PowerStack | 100-1,000 kWh | Factory & C&I | |
| CATL EnerC | 500+ kWh | Large industrial |
Estimate solar & BESS requirements for your factory
500 kW
25 %
10 hrs
Recommended Solar
163 kWp
RM 407,500 – RM 570,500
Recommended BESS
250 kWh
RM 375,000 – RM 625,000
Annual MD Saving
RM 133,905
RM 11,159 / mo
Simple Payback
5.8–8.9
years
After GITA, net investment reduces by ~34%
GITA reduces net cost by RM 266,050 on this system
Solar Rule of Thumb
1 kWp solar ≈ 0.7-1.0 kW daytime peak reduction. Losses from inverter efficiency, temperature, and cloud cover bring the effective offset to ~0.8 kW/kWp under Malaysian conditions.
BESS Rule of Thumb
Size BESS for 2-4 hours of storage at your target shaving rate. Targeting 100kW reduction for 3 hours = 300kWh minimum BESS. Add 20% buffer for DOD limits.
Verified results from Malaysian industrial solar+BESS installations
Penang
Electronics Manufacturing
Before MD
800 kW
RM 857,992/yr
-25%
After MD
600 kW
RM 643,398/yr
A Bayan Lepas electronics factory faced persistent MD spikes during afternoon production peaks (1-4pm). A 200kWp rooftop solar system, paired with 200kWh BESS for demand limiting, reduced their MD from 800kW to a consistent 600kW. The BESS demand controller was configured with a 620kW ceiling.
Shah Alam
Food & Beverage Processing
Before MD
400 kW
RM 428,760/yr
-20%
After MD
320 kW
RM 343,008/yr
A Shah Alam food processing facility operated 6am-6pm with consistent daytime peaks during cooking and cooling cycles. Solar alone achieved the target: 150kWp panels reduced daytime grid demand by 80kW, shifting MD from 400kW to 320kW. Night operations were minimal, making BESS unnecessary.
Johor Bahru
Automotive Parts Manufacturing
Before MD
1200 kW
RM 1,285,488/yr
-25%
After MD
900 kW
RM 964,116/yr
A Pasir Gudang auto parts factory ran 3 shifts with peaks at 6am startup and 2pm production peak. A 500kWp solar array combined with 500kWh BESS (with demand-limiting set at 920kW) reduced MD by 300kW. The GITA tax allowance reduced net investment by RM1.8M — bringing effective payback under 6.5 years.
Both components qualify — significantly improving ROI
GITA provides a 60% ITA on qualifying capital expenditure for both solar PV systems and BESS. This ITA is claimable against 70% of your statutory income in each assessment year.
At a 24% corporate tax rate, the 60% ITA on qualifying capex translates to approximately 34% reduction in net investment after tax savings. On a RM5M solar+BESS project, that is RM1.7M in tax savings.
GITA applications for solar and BESS are submitted through the Malaysian Green Technology Corporation (MGTC). Supporting documents include equipment specs, SEDA/TNB approval, and project details.
Projects must be approved before December 31, 2026 to qualify for the current GITA cycle. Early application is recommended as processing typically takes 2-3 months.
| Total Project Cost | RM 3,200,000 |
| Qualifying Capex (Solar + BESS) | RM 3,200,000 |
| 60% ITA Allowance | RM 1,920,000 |
| Tax Saving @ 24% | RM 460,800 |
| Effective Net Investment | RM 2,739,200 |
| Annual MD Savings | RM 428,000 |
| Net Payback Period | 6.4 years |
GITA approval required before Dec 31, 2026. Consult a qualified tax agent for specific advice on your entity's eligibility and ITA claim structure.
Peak shaving is the process of reducing your highest power demand intervals to lower your TNB Maximum Demand (MD) charge. Since TNB measures demand in 30-minute averages and bills you at RM89.27/kW/month for the single highest interval recorded that month, shaving even one or two peak intervals significantly reduces your monthly electricity bill.
Solar alone typically reduces daytime MD by 15-25% because it generates power during peak production hours (9am-4pm), directly offsetting your grid draw. However, solar cannot help with morning startup peaks (6-9am) or evening operations. For those periods, BESS (battery storage) is required.
It depends on when your peak demand occurs. If your factory peaks during daylight hours (10am-3pm), solar alone achieves 15-25% MD reduction at RM2.50-3.50/Wp. If peaks occur at morning startup, shift changes, or evening operations, adding BESS captures an additional 10-20% reduction. Solar+BESS together achieves 25-40% MD reduction with 4-7 year payback.
Yes. Both solar and BESS qualify for GITA (Green Investment Tax Allowance) through MGTC. The allowance is 60% ITA on qualifying capital expenditure, offset against 70% of statutory income. At a 24% corporate tax rate, this effectively reduces your net investment by approximately 34%. The GITA application deadline is December 31, 2026.
A general rule: 1 kWp solar reduces daytime peak by 0.7-1.0 kW; BESS should be sized for 2-4 hours of storage at your target shaving rate. For a 500kW MD factory targeting 100kW reduction, you would need approximately 150-200kWp solar and 200-400kWh BESS. The exact sizing depends on your load profile, operating hours, and peak patterns.
Popular BESS systems used in Malaysian industrial installations include Tesla Megapack (utility-scale), BYD Battery-Box (commercial/industrial), Sungrow PowerStack (industrial), and CATL-based systems. All qualify for GITA and support demand-limiting functionality required for automated peak shaving. Trexon Energy provides system selection, sizing, and installation services.
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Trexon Energy specializes in industrial peak shaving. We analyze your TNB bills, model your load profile, and design the optimal solar+BESS system — with full GITA application support.