Solar Calculator Malaysia 2026
A free solar panel calculator for Malaysian homes. Enter your monthly TNB bill to calculate how much solar you need, what you save each month, and the ROI and payback period under the Solar ATAP government scheme.
Costed on TNB's domestic tariff effective 1 July 2025 — including the Automatic Fuel Adjustment, the Energy Efficiency Incentive, KWTBB and the 8% service tax. Most calculators skip these and quote an average rate instead. See the method.
SuRIA Home rebate is still open. RM 600 per kWac, capped at RM 3,000, and already deducted from the payback figures below. Systems must be commissioned by 31 December 2026 — 120 days left, or until the allocation runs out. Eligibility and how to claim →
% of electricity used 8am–5pm. Typical: 30% working households, 60% WFH.
Your Solar Estimate
Your TNB bill, line by line
Tariff effective 1 July 2025. AFA +3.67 sen/kWh (September 2026).
| Charge | Now665 kWh | With solar466 kWh |
|---|---|---|
| Energy charge27.03 sen/kWh x 665 | RM 179.75 | RM 125.82 |
| Automatic Fuel Adjustment (AFA)+3.67 sen/kWh x 665 | RM 24.41 | RM 0.00 |
| Capacity charge4.55 sen/kWh x 665 | RM 30.26 | RM 21.18 |
| Network charge12.85 sen/kWh x 665 | RM 85.45 | RM 59.82 |
| Retail chargeRM10.00 per month | RM 10.00 | RM 0.00 |
| Energy Efficiency Incentive-5.5 sen/kWh x 665 | −RM 36.58 | −RM 55.86 |
| Service tax (8%) | RM 2.22 | RM 0.00 |
| KWTBB (1.6%) | RM 4.69 | RM 2.42 |
| Total monthly bill | RM 300.20 | RM 153.38 |
| Effective rate | 45.1 sen/kWh | 32.9 sen/kWh |
You cross a TNB threshold — worth RM 42.12/month on its own
- 600 kWhAFA waiver, RM10 retail waiver and 8% service tax exemption all return — RM 42.12/mo
These are step changes, not gradual savings. Using one kWh less takes the whole bill down by this much the moment you cross the line.
How this calculator works
Four steps, in the order the numbers depend on each other.
- 1. Your bill becomes consumption. A monthly bill in ringgit is converted back to kWh against the current tariff. This is not a division — the bill steps sharply at 600 and 1,500 kWh, so the same RM 800 can mean quite different consumption depending which side of a threshold you sit.
- 2. The system generates against your daytime load. Malaysian rooftops yield about 4.5 kWh per kWp per day. What you save directly is limited by how much of that you use while it is being generated — not by how big the system is.
- 3. The surplus is exported at the ATAP rate. RM 0.27/kWh below 1,500 kWh of household use, RM 0.37 above it, credited monthly with no rollover.
- 4. Two complete bills are compared. Not an average rate multiplied by kWh saved. This is the step almost every other calculator skips, and it is where the largest part of the saving hides.
Why crossing 600 kWh matters more than the kWh you save
TNB's domestic tariff has thresholds where charges switch on and off completely. They are steps, not slopes. At 600 kWh a month a household pays RM 215.98. One kilowatt-hour more and it pays RM 258.10 — a jump of RM 42.12 for a single unit of electricity, because three separate reliefs disappear at once:
- The Automatic Fuel Adjustment starts applying to every kWh, not just the excess.
- The RM10 monthly retail charge is no longer waived.
- The 8% service tax exemption is lost on consumption above 600 kWh.
A solar system that takes a household from 700 kWh to 400 kWh does not simply remove 300 kWh of energy — it restores all three reliefs and moves the home into a far better Energy Efficiency Incentive band. That is why the saving shown above is larger than an average-rate estimate, and it is the single most common reason quoted solar savings come in low.
| Threshold | Cost of one kWh over | What changes |
|---|---|---|
| 300 kWh | +RM 5.86 | KWTBB levy begins; incentive band drops |
| 600 kWh | +RM 42.12 | AFA, retail charge and service tax all switch on |
| 1,000 kWh | +RM 5.77 | Energy Efficiency Incentive stops entirely |
| 1,500 kWh | +RM 160.24 | Energy charge rises from 27.03 to 37.03 sen on every kWh |
Computed live from the tariff engine at AFA +3.67 sen/kWh (September 2026).
How much solar do I need? Sizing by TNB bill
A starting point for a household using roughly 30% of its electricity during daylight hours. Raise the daytime figure in the calculator if you work from home — it changes the answer more than anything else on the page.
| Monthly bill | Consumption | Suggested size | Generates |
|---|---|---|---|
| RM 200 | 556 kWh | 1 kW | 135 kWh/mo |
| RM 300 | 665 kWh | 1.5 kW | 203 kWh/mo |
| RM 450 | 896 kWh | 2 kW | 270 kWh/mo |
| RM 600 | 1,163 kWh | 2.5 kW | 338 kWh/mo |
| RM 900 | 1,500 kWh | 3.5 kW | 473 kWh/mo |
| RM 1,300 | 2,069 kWh | 4.5 kW | 608 kWh/mo |
Full pricing per size in the Malaysia solar panel cost guide.
Solar calculator questions
How do I calculate solar savings from my TNB bill?
Work out the two bills, not the difference in kWh. Convert your monthly bill to consumption, subtract the solar you actually use during daylight hours, then price that new consumption as a complete TNB bill. It matters because the tariff is not linear: dropping under 600 kWh a month restores the AFA waiver, the RM10 retail charge waiver and the 8% service tax exemption in one step, worth RM 42.12 a month by itself. Pricing the saving at an average rate per kWh misses all three.
What size solar system do I need in Malaysia?
Size to your daytime load, not your total bill. A kilowatt of rooftop solar in Malaysia generates roughly 4.5 kWh a day, about 135 kWh a month. A typical working household uses about 30% of its electricity between 8am and 5pm, so an RM 450 bill (around 896 kWh) suits roughly 2 kW. Going bigger does not waste the power, but the extra is exported at 0.27 sen rather than offsetting electricity you would have paid about 50 sen for.
How much does a solar system cost in Malaysia?
Residential installations run roughly RM 3,500–5,000 per kWp fully installed, so a 5 kW system is about RM 18,000–25,000 and a 10 kW system about RM 35,000–48,000. The SuRIA Home rebate currently returns RM 600 per kWac, capped at RM 3,000, which comes straight off that price. Batteries are separate and add roughly RM 15,000–25,000.
What is the Solar ATAP export rate?
Under Solar ATAP, electricity you export is credited at RM 0.27/kWh if your household uses 1,500 kWh a month or less, and RM 0.37/kWh above that. Credits offset your bill and reset monthly — they do not roll over for 24 months the way NEM 3.0 credits did, which is why sizing to your own daytime use matters more under ATAP than it did under NEM.
Is this solar calculator accurate?
It prices every figure on TNB's domestic tariff effective 1 July 2025 — energy, capacity and network charges, the Automatic Fuel Adjustment, the Energy Efficiency Incentive, the RM10 retail charge, KWTBB and the 8% service tax — and shows you each line rather than only a total. AFA is the one component that changes monthly; this page is billing September 2026 at +3.67 sen/kWh. Generation is modelled at 4.5 kWh per kWp per day; real output varies about ±10% with shading, orientation and weather.
Is this solar calculator free?
Yes — free, no sign-up, no email required, and nothing is stored. Move the sliders and the numbers update in your browser. You only give a contact detail if you decide to ask for installer quotes at the end, and that is optional.
How do I calculate solar ROI in Malaysia?
ROI is the total benefit over the system's life minus what you paid, and the honest version needs three inputs most calculators skip. Take the monthly benefit — bill saving plus export credit, not one or the other — multiply by 12 and by the 25-year panel life, then subtract the installed price after any rebate. The calculator above does exactly this and shows each part, so you can see how much of the return is self-consumption versus export. Payback period is the same sum expressed as time: net cost divided by annual benefit.
What government scheme covers solar panels in Malaysia?
Solar ATAP, run by SEDA and the Energy Commission, is the current rooftop scheme for homes on TNB supply in Peninsular Malaysia — it replaced NEM 3.0. You self-consume what you generate and export the surplus for bill credit at RM 0.27/kWh, or RM 0.37 above 1,500 kWh of household use, with credits reset monthly. Sabah and Labuan run SESB NEM and Sarawak runs SEB SARES instead, so Solar ATAP does not apply there.
Does the calculator work for single-phase and three-phase supply?
Yes — the savings maths is identical, because TNB's domestic tariff is charged per kWh regardless of phase. Phase matters for the system size your switchboard can take, not for the tariff. Single-phase supply is generally limited to about 5 kW of inverter capacity; above that you will usually need three-phase, which most semi-detached and bungalow properties already have.
Next steps
Estimates only, not a quotation. Generation varies with shading, roof orientation and weather; installed prices vary by installer and roof complexity. Tariff figures follow TNB's published domestic schedule effective 1 July 2025 and the Energy Commission's monthly AFA. SolarAtapMY is independent and not affiliated with TNB or SEDA.