Solar ATAP Capacity: 5kW Single-Phase or 15kW Three-Phase?

Malaysia’s Solar ATAP rules distinguish domestic capacity by supply phase: generally up to 5kW for a single-phase home and up to 15kW for a three-phase home. These figures answer what may be allowed, not what every house should install.

First confirm the supply phase

Your latest TNB bill, meter information or distribution board can help identify whether the property is single-phase or three-phase. Do not decide from house size alone. A large house can still have a single-phase supply, while a smaller property with heavier electrical demand may already use three-phase.

A phase upgrade is an electrical and utility decision, not a shortcut to justify more panels. It can affect the distribution board, cabling, protection, approval work and total project cost.

The capacity ceiling is not the design target

A responsible proposal starts with at least three months of kWh usage, the hours when electricity is consumed, roof direction, shading, usable roof area and expected changes such as an EV or additional air-conditioning. If daytime demand is low, installing at the maximum threshold may create more export than the household can use effectively within the same billing period.

Compare DC panel capacity and AC inverter capacity

Solar quotations may show both kWp for the panel array and kWac for the inverter. They are related but not interchangeable. Ask the provider to state the panel quantity and wattage, total DC size, inverter AC rating, assumed losses and the programme capacity basis. A larger DC array paired with a smaller inverter may be a deliberate design choice, but the clipping and generation assumptions should be visible.

Four checks before accepting a size

1. Confirm phase type and the applicable capacity threshold.
2. Plot typical weekday and weekend daytime load.
3. Check roof condition, orientation, shade and fire-safe access.
4. Separate direct self-consumption, export and night imports in the savings model.

HOMI can review the bill and roof information before a site visit. For the settlement context, read why a TNB bill may remain after Solar ATAP.

This article reflects official information checked on 1 August 2026 and is general guidance. Programme rules, tariff treatment, approval and actual savings remain subject to the latest PETRA, SEDA, Energy Commission and TNB requirements plus the property bill, roof and usage pattern.