Model your project savings and peak-demand reduction
Calculate ROIPeak Shaving with Solar & BESSHow Malaysian Factories Cut MD Charges with Solar + BESS
TNB Maximum Demand charges can be a large share of a factory electricity bill. Battery storage (BESS), on its own or charged by solar, is how factories shave demand peaks: a well-sized system can cut MD by 15-30%. Solar alone mainly cuts energy (kWh) charges.
Explore BESS Malaysia system options, or start with solar for factory roofs.
15-30%
MD Reduction with Solar + BESS
RM89.27
Per kW/Month (TNB MV General)
~5.5yr
Solar Payback with GITA (MV General)
100%
GITA Tier 1 Allowance for BESS
What Is Peak Shaving?
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. Discharging stored energy from a battery (BESS) during the peak offsets grid draw and reduces the number reported to TNB — and the charge that follows. Solar alone does not reliably lower MD, because one cloudy half-hour can still set the month's peak.
How TNB Measures Maximum Demand
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.
The MD Charge Math
MD Charge Cost Calculator
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 Medium Voltage General tariff at RM89.27/kW/month (from 1 July 2025)
3 Peak Shaving Technologies Compared
Choose the right approach based on your load profile and budget
Solar Only
Not reliable alone
MD Reduction
~RM2.40/Wp (before SST)
Cost
~6.4 years (~5.5 with GITA), MV General
Payback
Lowest capex of the three options
Simplest installation and maintenance
Cuts energy (kWh) charges every sunny day
GITA Tier 2 (60%)
One cloudy half-hour can set the month's MD
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
BESS Only
15-30%
MD Reduction
Quoted per site
Cost
Site-specific
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
Solar + BESS
15-30%
MD Reduction
Quoted per site
Cost
Site-specific
Payback
Cuts both energy and MD charges
Solar charges BESS during the day
BESS covers morning and evening peaks
GITA on both: 60% solar, 100% BESS
Uses more of your own solar output
Highest total capex
More complex system integration
Larger roof/land footprint required
Best For
Factories with both daytime energy use and MD peaks, especially with GITA support
How Solar Peak Shaving Works
Step-by-step: what happens during daylight hours
24-Hour Factory Load Profile
Toggle to see how solar and BESS shave demand peaks
Morning Startup Peak
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 Generation Ramps Up
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.
Peak Solar + Peak Offset
Solar is at maximum output (95-100%) and offsets your grid draw kW-for-kW. But a single cloudy half-hour in the month can still set your MD, so solar alone does not reliably lower it; BESS can cover those intervals.
Solar Tapering, Demand Continues
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.
No Solar — Grid Only
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, and one cloudy half-hour can set the month's MD. For reliable MD reduction — and for peaks outside daylight hours — BESS is essential.
How BESS Adds the Missing Piece
Battery storage closes the gap solar cannot cover
Charge from Solar (Daytime)
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.
Charge from Grid Off-Peak (Optional)
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.
Demand Limiting (Automatic Peak Shaving)
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.
Flatten the Curve Month After Month
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.
Popular BESS for Malaysian Industrial Use (market reference, not stocked by Trexon)
| 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 |
Sizing Your Peak Shaving System
System Sizing Tool
Estimate solar & BESS requirements for your factory
500 kW
25 %
10 hrs
Indicative Solar
163 kWp
RM 391,200 (illustrative, RM2,400/kWp before SST)
Indicative BESS
250 kWh
RM 325,000 – RM 525,000 (market estimate RM1,300–2,100/kWh, quoted per site)
Annual Saving (MD; energy for solar only)
RM 133,905
RM 11,159 / mo
Simple Payback
5.3–6.8
years
After GITA, net investment reduces by ~14.4% (solar) to ~24% (BESS)
GITA reduces net cost by RM 134,333 on this system
Solar Rule of Thumb
Solar alone gives no reliable MD saving: the monthly peak can fall during cloud cover or after sunset. The BESS is what shaves peak demand.
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.
GITA Tax Incentive for Solar & BESS
Both components qualify — significantly improving ROI
60% (Solar) / 100% (BESS) Tax Allowance
GITA Asset gives a 60% allowance (Tier 2) on qualifying solar PV capex and 100% (Tier 1) on qualifying BESS capex, claimable against up to 70% of your statutory income in each assessment year.
~14–24% Effective Cost Reduction
At a 24% corporate tax rate, the allowance translates to tax savings of roughly 14.4% of qualifying solar capex and 24% of qualifying BESS capex.
Application via MGTC
GITA Asset applications for solar and BESS are submitted to the Malaysian Green Technology and Climate Change Corporation (MGTC) through MyHIJAU, after commissioning. Supporting documents include equipment specs, SEDA/TNB approval, and project details.
December 31, 2026 Deadline
Projects must be commissioned and submitted by 31 December 2026 to qualify for the current GITA cycle. The application can only be submitted after commissioning, so plan installation early.
GITA Example (Illustrative): 500kWp Solar + 400kWh BESS
| Solar Capex (500kWp × RM2,400, before SST) | RM 1,200,000 |
| Solar GITA Allowance (Tier 2, 60%) | RM 720,000 |
| Solar Tax Value @ 24% | RM 172,800 |
| BESS Capex (400kWh) | Quoted per site |
| BESS GITA Allowance (Tier 1, 100%) | 100% of BESS capex |
| BESS Tax Value @ 24% | RM 24,000 per RM100,000 |
| Set-off limit | Up to 70% of statutory income/yr |
GITA: commission and submit by 31 Dec 2026. Consult a qualified tax agent for specific advice on your entity's eligibility and ITA claim structure.
Frequently Asked Questions
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.
Not reliably. Solar offsets your grid draw during daylight, but MD is set by the single highest 30-minute window in the month, so one cloudy half-hour during production can erase the reduction. Solar alone mainly cuts energy (kWh) charges. For MD reduction, and for morning startup (6-9am) or evening peaks, BESS (battery storage) is required.
It depends on your load. Solar on its own cuts energy (kWh) charges at about RM2.40/Wp (before SST), with a typical payback of about 6.4 years on MV General (about 5.5 years with GITA), but it does not reliably lower MD. To cut MD, add BESS with demand limiting: a well-sized solar+BESS system can reduce MD by 15-30%. We size it from 12 months of your TNB bills and interval data.
Yes. Solar PV qualifies for GITA (Green Investment Tax Allowance) Tier 2 at 60% and BESS for Tier 1 at 100%, through MGTC, offset against up to 70% of statutory income. At a 24% corporate tax rate, this saves roughly 14.4% (solar) and 24% (BESS) of qualifying capex. Systems must be commissioned and the application submitted by December 31, 2026.
Solar alone gives no reliable maximum demand (MD) saving, because the MD peak can occur when output is low (cloud, evening) or outside solar hours. The BESS is what shaves peak: size it for 2-4 hours of storage at your target shaving rate. For a 500kW MD factory targeting 100kW reduction, you would typically look at roughly 200-400kWh BESS, with solar sized separately for energy savings. The exact sizing depends on your load profile, operating hours, and peak patterns.
Common C&I BESS options in Malaysia include BYD, Sungrow PowerStack, Huawei and CATL-based systems; utility-scale projects use products such as Tesla Megapack. GITA eligibility depends on the specific model being verified by MGTC and listed under MyHIJAU, and the system must support demand limiting for automated peak shaving.
Learn More
Peak Shaving Solutions
Our industrial peak shaving services
TNB MV Tariff Guide
Full medium voltage tariff breakdown
MD Charge Reduction Guide
5 strategies to cut MD charges
Solar Tax Allowance 2026
GITA, ITA, and ACA guide
TNB Tariff 2026
All TNB tariffs explained
TNB TOU Tariff & Solar
Time-of-Use rates & solar strategy
Energy Efficiency Hub
Full industrial energy toolkit
Solar Calculator
Calculate your savings
Contact Us
Speak to a peak shaving engineer
Manufacturing Solar
Solar for factories
Ready to Reduce Your Energy Costs?
Request a commercial solar assessment. Our commercial team will review the submitted project details during business hours.
- Sizing from your 12 months of TNB bills and shift pattern
- Roof, switchboard and single-line diagram reviewed by our engineers
- Available incentives (GITA for solar, subject to MGTC verification) and Solar ATAP eligibility checked for your premises
- SEDA-registered PV Service Provider (RPVSP-2026/373) · SSM 201301044881 (1074704-D)
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Send us 12 months of TNB bills, your roof plan, single-line diagram and a meter photo. We model your load profile and design a solar+BESS system sized to your peaks, with the documents you need for GITA.