If your savings are sitting in a fixed deposit, you may feel the pinch every time your TNB bill arrives. Here is a question worth asking seriously: what if RM 17,999 worked harder on your rooftop than it does in a bank account? The answer depends mostly on your bill, so this guide runs the numbers on the RP4 tariff.
The Headline Numbers: Solar vs Fixed Deposit in Malaysia
We use a 7.44 kWp residential solar system (RM 17,999 with a Solis inverter; the size our savings engine matches to a RM 500 monthly bill) as the benchmark. Fixed deposit rates change, so we use an illustrative 3.0% a year; replace it with the current rate on your bank's own page.
Estimate on the RP4 domestic tariff (from 1 Jul 2025), before AFA, the 1.6% RE Fund and service tax; 3.5 sun-hours a day; about 40% of solar used at home and the rest exported and credited at the 27.03 sen Energy Charge (capped at what you import) for 10 years under Solar ATAP; no tariff increases. Your bill and roof will change the figures. Fixed deposit figures are illustrative.
| Option | Capital | Annual Return | Return Type | 25-Year Outcome |
|---|---|---|---|---|
| Solar (7.44 kWp, RM500 bill) | RM 17,999 | about 19% simple annual return (about RM 3,492 a year) | Bills avoided + Solar ATAP export credit | about RM 69,120 of electricity savings (about RM 51,121 after the system price) |
| Fixed Deposit (illustrative 3.0% a year, compounding) | RM 17,999 | 3.0% (about RM 540 in year 1) | Interest income | about RM 37,686 balance (about RM 19,687 of interest) |
Solar is not guaranteed: its return depends on your bill, your daytime use and your roof. But on a RM 500 bill the gap over 25 years is large. Let us break down how the numbers work.
Solar Numbers on the RP4 Tariff
System Cost
- 7.44 kWp system (Solis inverter, complete installation): RM 17,999 (Huawei adds RM 3,000, Sungrow adds RM 5,000)
Monthly Returns
- Monthly generation: about 781 kWh (7.44 kWp x 3.5 sun-hours x 30 days)
- Used at home (about 40%): about 312 kWh, avoiding about RM 0.4443/kWh
- Exported via Solar ATAP (about 60%): about 469 kWh, credited at RM 0.2703/kWh up to the units you import
- Bill: RM 500 before solar, about RM 209 after
- Monthly saving: about RM 291
- Annual saving: about RM 3,492
Simple Payback Calculation
RM 17,999 / RM 3,492 a year = about 5.2 years payback. After that you keep saving on your bill for the remaining life of the system.
It Depends on Your Bill
| Monthly bill | System (Solis) | Simple annual return | Payback |
|---|---|---|---|
| RM 200 | 5.58 kWp, RM 15,999 | about 11% | about 9.3 years |
| RM 300 | 5.58 kWp, RM 15,999 | about 14% | about 7.2 years |
| RM 500 | 7.44 kWp, RM 17,999 | about 19% | about 5.2 years |
| RM 1,000 | 11.78 kWp, RM 25,999 | about 28% | about 3.6 years |
The 25-Year Comparison Table
This table assumes: a fixed deposit at an illustrative 3.0% compounding; solar savings with no tariff change and no degradation; and export credit counted for the first 10 years only (the Solar ATAP contract runs up to 10 years), which is why savings grow more slowly after year 10.
| Year | FD Balance (RM 17,999 @ 3.0%) | FD Interest Earned | Solar Cumulative Savings | Solar Savings Less System Price |
|---|---|---|---|---|
| Year 5 | RM 20,866 | RM 2,867 | RM 17,460 | −RM 539 (not yet paid back) |
| Year 10 | RM 24,189 | RM 6,190 | RM 34,920 | RM 16,921 |
| Year 15 | RM 28,042 | RM 10,043 | RM 46,320 | RM 28,321 |
| Year 20 | RM 32,508 | RM 14,509 | RM 57,720 | RM 39,721 |
| Year 25 | RM 37,686 | RM 19,687 | RM 69,120 | RM 51,121 |
Note: Solar cumulative savings are the bills avoided and export credit earned, not the residual system value, and they are not reinvested. FD balance includes principal and compound interest at the illustrative rate. Panel degradation and tariff changes are not modelled.
Inflation and Fixed Deposits
Compare your fixed deposit rate with inflation yourself: if the two are close, your real return is near zero. Solar savings move with TNB's charges. If the charges rise, your savings rise; if they fall, your savings fall. We assume no change in our examples.
Risk Comparison: Is Solar Actually Safe?
The main objection to treating solar as an investment is risk. Fair point, so let us address it honestly.
Solar Risks (and how they are mitigated)
- Panel degradation: Standard panel warranties guarantee a minimum share of output at year 25 (for example 80%).
- Inverter failure: Inverters carry manufacturer warranties (for example 10 years for Huawei and Sungrow) and may need replacing during the life of the system, which is a cost to budget for.
- Policy change: Solar ATAP export credit is set by the Energy Commission and SEDA rules. Our examples count it for 10 years only; self-consumption savings do not depend on it.
- Your bill: Savings depend on how much electricity you use. If your usage falls, so do your savings.
FD Risks
- Real returns can be near zero after inflation
- Rate risk: rate cuts directly reduce your income
- Opportunity cost: capital locked in a low-yield instrument
- PIDM protection has a limit per depositor: worth noting for large balances
The Dual Strategy: Solar AND Fixed Deposit
We are not suggesting you empty your savings account. A hybrid approach:
- Maintain an emergency fund in FD (liquid, safe)
- Invest in solar to cut your electricity bill
- Redirect part of the bill you no longer pay into FD or other savings monthly
When your electricity bill falls, that money can flow into other savings. Solar does not just give you returns: it frees up monthly cash flow to accelerate your other financial goals.
Getting Started: What You Need
A 9.92 kWp system (16 panels) needs about 45 square meters of unshaded roof. Before committing, you can get a free quote, which includes:
- Roof suitability and shading analysis
- TNB bill analysis to size your system correctly
- ROI projection based on your actual consumption pattern
- Full quote with Solar ATAP eligibility confirmation
Use our Solar Savings Calculator for an instant estimate, or compare our solar pricing packages to see all-inclusive costs by system size. If you want to understand the full Solar ATAP program, our Solar ATAP guide has everything you need.
The bottom line: Fixed deposits are safe and flexible. Solar is a long-term asset whose return depends on your bill. Run your own numbers before you decide.
