Industrial Solar Malaysia: Solar for Medium-Voltage Factories, Plants and Industrial Parks

Who this page is for

This page is for factories, manufacturing plants and industrial-park facilities billed on TNB's medium- or high-voltage tariffs — the commercial C1/C2 and industrial E1/E1s/E2/E3 categories — where a maximum-demand charge sits alongside the energy rate. If your site is a low-voltage office, retail unit or hotel, Commercial solar covers that tariff and load profile instead; if you need a single rooftop project scoped for one operating factory rather than the wider tariff and connection detail, Solar for factory goes deeper on shifts, roof and delivery.

Sector guides cover rubber glove and rubber-goods plants, electronics and semiconductor facilities and food and beverage plants — each with its own shift pattern, cleanroom or cold-chain constraint, and roof condition. Multi-site groups, round-the-clock plants and sites inside a gazetted industrial park are all in scope.

How TNB charges a medium-voltage industrial site

An industrial bill above the low-voltage threshold is built from several separate charges, not one blended rate: an energy charge per kWh consumed, a maximum-demand (MD) charge billed per kW, a network charge, the KWTBB renewable-energy fund levy, and the ICPT surcharge, which resets roughly every six months. On time-of-use tariffs the peak window runs 08:00–22:00, Monday to Friday — covering the whole of a single-shift factory's working day and overlapping every hour a rooftop system generates, so solar output lands in the most expensive part of the bill.

The maximum-demand charge itself is not based on total energy used. It is set by the single highest 30-minute average demand TNB's meter records during the whole billing month, multiplied by the RM/kW maximum-demand rate printed on that bill's own "Maximum Demand" line. One half-hour spike, even once a month, sets the charge for the entire month. Trexon does not publish a current MV/HV maximum-demand rate here — it has to be read from your own live bill — so our engineering review always starts by pulling the last 12 months of MD history from your TNB statements.

Low-voltage industrial customers on Tariff D carry no separate maximum-demand line of their own — only the energy, retail and KWTBB charges apply. The MD charge begins on the medium-voltage C1/C2 and E1/E1s/E2/E3 tariffs used by larger factories, plants and industrial-park tenants once demand moves off low voltage, which is why the worked example below (Tariff D) illustrates energy savings only, and the maximum-demand mechanics are explained structurally rather than with a rate.

How much do industrial solar panels cost in Malaysia?

There is no single per-kWp answer for an industrial site — installed cost is driven by factors a small rooftop project never sees: the roof type (metal deck, concrete, or a mix of ages and pitches across several blocks), whether the connection point needs medium-voltage interconnection work at the substation, whether a protection study and an updated single-line diagram (SLD) are needed before TNB approves the export, and how much shutdown-window flexibility production can offer for the switchgear tie-in. Two factories of the same size can carry very different costs once these are priced in, which is why Trexon quotes from a completed engineering review rather than a size-only estimate.

A remote review — starting from your last 12 months of TNB bills and, where available, interval load data — establishes the tariff category, MD history and a first-pass system size at no cost. When roof, switchgear and access constraints need to be verified in person, Trexon offers a priority engineering site visit for RM100, fully credited toward your project if you proceed.

Sizing an industrial system: worked example

Sizing starts from the bill and the shift pattern, not the roof alone. Trexon's proposal engine assumes roughly 94.6 kWh of generation per kWp per month for a well-oriented Malaysian rooftop (30 days × 3.8 average sun-hours × an 83% performance ratio), then multiplies that by how much of the generation the site actually self-consumes — which depends heavily on shift pattern. The worked example below uses Tariff D, TNB's low-voltage industrial rate, and a single-shift factory archetype, because Tariff D is the only industrial rate this page can publish; medium- and high-voltage rates have to be read from your own current bill, as explained above.

For sites that do carry a maximum-demand charge — the medium-voltage tariffs — the saving follows a second, separate formula: MD saving = solar/demand coincidence × the solar system's AC rating (kWac) × your bill's own RM/kW maximum-demand rate. For a single-shift factory, Trexon's archetype model puts that coincidence at around 85% — most of the plant's peak demand happens in daylight hours when the array is producing — though the true figure depends on exactly when your own demand peak falls relative to sun hours.

System size itself is also bounded by the Solar ATAP export scheme: a non-domestic installation is capped at 100% of the site's maximum demand (kWac), with a hard ceiling of 1,000 kW per installation (GP/ST/No. 60/2025 §8.3 and §8.5). DC-oversized or battery-buffered designs are permitted as long as the inverter's AC rating fits inside that cap — useful on sites where roof area exceeds what the MD cap alone would allow.

Own, borrow, instalment or PPA?

Four ownership routes cover almost every industrial project. Which one fits depends on whether your balance sheet wants to claim GITA and capital allowances, how much upfront capital the project can absorb, and whether the finance team prefers an operating-expense or capital-expense structure.

Tax incentives for manufacturers

Solar PV bought for a manufacturer's own consumption can qualify for the Green Investment Tax Allowance (GITA) Asset, Tier 2, subject to MGTC approval: an allowance equal to 60% of qualifying capital expenditure, which can be set off against up to 70% of a company's statutory income for the year of assessment, within a window that currently runs to 31 December 2026. Separately, the equipment can also qualify for standard capital allowances as plant and machinery. Read the mechanics in the GITA tax incentive guide or the capital allowance guide, and see GITA tax filing support for how Trexon supports the MGTC application.

Indicative only. Subject to MGTC/MIDA approval, applicable tax law and confirmation by the customer’s licensed tax adviser. Official GITA Asset window ends 31 December 2026.

Connection, shifts and site considerations

Shift pattern changes the economics more than almost anything else. A single-shift factory typically self-consumes around 98% of what a correctly sized system generates, because production runs inside daylight hours; a three-shift, round-the-clock plant self-consumes closer to 70%, because a large share of load falls outside sun hours. A 24/7 plant still benefits — the daytime portion of load is still displaced, and the maximum-demand saving still applies wherever the demand peak coincides with generation — and pairing solar with battery storage is worth modelling for sites that run more shifts; see BESS for commercial and industrial sites for that pairing, and energy efficiency for reviewing major loads before finalising system size.

Sites drawing above roughly 100 kW of demand are usually already on a medium-voltage connection, commonly 11 kV, and some larger or multi-building sites connect behind their own step-down transformer rather than at the TNB boundary. Both arrangements are routine for an industrial project — they change where the protection study, single-line diagram and switchgear tie-in happen, not whether the project is feasible. Power factor also matters more on a large motor-heavy load than on an office; see the power factor / kVArh penalty guide for how a poor power factor already costs a site money independent of solar.

For manufacturers whose site can't host enough rooftop for their load — or who want grid-delivered green power without an installation at all — CRESS provides physically delivered green electricity via the TNB grid, and utility-scale projects sized well beyond rooftop capacity fall under the LSS5 large-scale solar programme instead of a rooftop EPC scope.

Park-specific guides cover the manufacturing profile and grid context of several major Malaysian industrial parks — see the industrial parks overview — including:

• Pasir Gudang Industrial Area, Johor
• Senai Airport City, Johor
• Shah Alam Seksyen 15, Selangor
• Pulau Indah Industrial Park, Selangor
• Kulim Hi-Tech Park, Kedah
• Batu Kawan Industrial Park, Penang

From project brief to commissioning

Every industrial project follows the same sequence, though the depth of the engineering step depends on voltage level and connection complexity:

• Project brief received — tariff, bills, shift pattern and site details.
• Remote engineering review — tariff category, MD history and first-pass sizing.
• Site verification — roof, switchgear, single-line diagram and protection study (RM100 priority visit where a physical inspection is needed).
• Solar ATAP application and TNB approval.
• Installation, commissioning and performance verification.