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Configure solarMost homeowners don't know if they're on single phase or three phase — until a solar installer tells them they can't get the system they wanted. This guide fixes that. Check your phase in 2 minutes and know exactly what solar system you can install.
Single phase (2 wires) = max 5kWac solar. Ideal for bills RM350–RM550/mo.
Three phase (4 wires) = max 15kWac solar. Ideal for bills RM300–RM1,000+/mo.
Bill >RM400 but single phase? You may need to upgrade first (RM3K–10K).
Malaysia's electricity grid distributes power through a three-phase system. Think of it as three separate streams of electricity, offset from each other. Your TNB connection taps into this grid — either drawing from one stream (single phase) or all three (three phase).
For solar, this matters enormously: TNB's Solar ATAP programme caps the system size based on your phase. A single phase home is limited to 5kWac. A three phase home can go up to 15kWac — 3x more power.
| Voltage | 230V |
| Wires | 2 wires |
| Max Current | 60A (13.8kW) |
| Max Solar | 5kWac |
Terrace houses, apartments, small semi-Ds
| Voltage | 400V (line-to-line) |
| Wires | 4 wires |
| Max Current | 60A per phase |
| Max Solar | 15kWac |
Large semi-Ds, bungalows, commercial
Why Most Terrace Houses Are Single Phase
When TNB wired Malaysian terrace houses in the 1970s–2000s, typical household loads were low (ceiling fans, small TVs, basic lighting). Single phase 230V at 60A was more than enough. Today, with 3+ ACs, water heaters, and EVs, many homeowners are hitting the limits — and solar makes this constraint more visible.
You don't need an electrician to figure this out. Pick the easiest method for you.
Not sure? Answer these 3 quick questions:
How many ACs do you have?
What is your average monthly TNB bill?
What type of house?
TNB's Solar ATAP programme sets hard limits based on your electrical phase. These are not negotiable.
| System | System Size | Panel Capacity | Suitable Bill Range | Est. Monthly Savings |
|---|---|---|---|---|
Single Phase | 5kWac (7.44kWp) | ~10–12 panels | RM350–RM550/mo | RM180–RM250/mo |
Three Phase | 15kWac (19.84kWp) | ~24–26 panels | RM300–RM1,000+/mo | RM450–RM800/mo |
Important: The 5kW Cap Catches People Off Guard
Many homeowners see friends with 10kW+ solar systems and assume they can get the same. Then they discover they're on single phase and are limited to 5kW. The 5kW limit is a TNB grid stability requirement, not an installer limitation — it applies uniformly across all single phase connections in Malaysia.
Not everyone needs to upgrade. Use this decision guide to find out if it makes sense for you.
Tip: If you're upgrading for solar, bundle the upgrade with the solar installation. Some contractors offer combined packages that save RM500–RM1,500 versus doing them separately.
Single phase and three phase systems use different inverter models. These are not interchangeable. Here are the best options available in Malaysia for 2026.
| Model | Capacity | Price (MYR) | Warranty | Efficiency | Best For |
|---|---|---|---|---|---|
| Sungrow SG3.0RS-ADATop Pick | 3kW | RM 1,800–2,200 | 10 yr | 98.4% | Best value / most popular |
| Sungrow SG4.0RS | 4kW | RM 2,000–2,500 | 10 yr | 98.4% | Maximum single-phase output |
| Huawei SUN2000-4KTL-L1 | 4kW | RM 2,200–2,800 | 10 yr | 98.6% | FusionSolar app, smart optimizer |
| Solis S6-GR1P3K | 3kW | RM 1,600–2,000 | 10 yr | 97.7% | Budget-conscious buyers |
Trexon's Pick 2026: Sungrow SG3.0RS-ADA: Best price-to-reliability for Malaysian single phase homes. iSolarCloud monitoring, 10-year warranty, SIRIM & TNB certified.
| Model | Capacity | Price (MYR) | Warranty | Efficiency | Best For |
|---|---|---|---|---|---|
| Huawei SUN2000-10KTL-M1Top Pick | 10kW | RM 5,500–7,000 | 10 yr | 98.6% | Best monitoring + smart optimizer |
| Sungrow SG10RT | 10kW | RM 4,800–6,000 | 10 yr | 98.4% | Best value 3-phase |
| Solis S6-GR3P10K | 10kW | RM 4,200–5,500 | 10 yr | 98.0% | Budget 3-phase option |
| GoodWe GW10KT | 10kW | RM 4,500–5,800 | 10 yr | 98.3% | Reliable 3-phase with SEMS portal |
Trexon's Pick 2026: Huawei SUN2000-10KTL-M1: Best-in-class monitoring via FusionSolar, smart PV optimizer compatible, 10-year warranty. Ideal for high-bill homes that want granular data.
All inverters listed are SIRIM-certified and TNB Solar ATAP approved for Malaysian residential use (2026).
Want a deep-dive on inverter types? Read our String Inverter vs Micro Inverter Malaysia 2026 guide.
Real 2026 pricing from Trexon installations in Klang Valley. Includes panels, inverter, mounting, wiring, permits, and monitoring app.
| System | Total Cost | Monthly Savings | Annual Savings | Payback Period | CO2 Saved/yr |
|---|---|---|---|---|---|
| 4kW Single Phase | RM 12,000–16,000 | RM 180–250 | RM 2,160–3,000 | 5–7 years | 2.4 tonnes |
| 4kW + Phase Upgrade | RM 15,000–26,000 | RM 180–250 | RM 2,160–3,000 | 7–9 years | 2.4 tonnes |
| 10kW Three Phase | RM 35,000–48,000 | RM 450–800 | RM 5,400–9,600 | 5–7 years | 6.0 tonnes |
| 10kW + Phase Upgrade | RM 38,000–58,000 | RM 450–800 | RM 5,400–9,600 | 6–8 years | 6.0 tonnes |
These figures assume Malaysian average solar irradiance of 4.5 peak sun hours/day, TNB domestic tariff at RM0.571/kWh (Block C), and Solar ATAP export credit at RM0.31/kWh for exported energy.
If you need to upgrade from single to three phase before installing 10kW solar, add RM3,000–RM10,000 to the three phase system cost. Even with the upgrade, the payback period remains under 8 years for most high-bill households.
Our solar engineers will identify your phase, assess your roof, and recommend the optimal system size — no obligation, no pushy sales.
SEDA-registered installer • 500+ installations • Serving Klang Valley, Selangor, KL, Penang & Johor