Solar ATAP Changes 2026: Why You Must "Right-Size" Your System
Critical Policy Change
Under the new Solar ATAP program replacing NEM 3.0, excess solar energy exported to the TNB grid no longer carries forward to the next billing cycle. Any unused credit at the end of each billing period is forfeited.
For years, the standard advice from Malaysian solar companies was simple: "Install the biggest solar system your roof can fit." Under the old Net Energy Metering (NEM) 3.0 program, this made perfect sense. If you generated more electricity than you used, TNB stored those credits in your account, and you could use them months later.
In 2026, with the introduction of the Solar ATAP program, that strategy is dead. Over-sizing your solar system is now a costly mistake.
The Big Change: No More Credit Carry-Forward
Under Solar ATAP, the fundamental mechanism of how you are compensated for exported energy has changed.
- Old NEM 3.0: Excess energy exported to the grid was converted into credits. These credits could be carried forward to later bills. You could generate massive excess in sunny January and use those credits to pay for high air-conditioning usage in hazy June.
- New Solar ATAP: You are still credited for energy you export (at the current Energy Charge rate), but the credits apply strictly to the current billing period. If your exported credits exceed your energy cost for that billing period, the remaining credit is forfeited at the end of the period. You lose it.
Why "Right-Sizing" is the New Standard
Because you cannot save credits for a rainy day, the goal is no longer maximum generation—it is maximum self-consumption.
You need a solar system that perfectly matches your daytime energy consumption profile, with just enough excess to offset your nighttime usage for that specific 30-day period.
The Cost of Over-Sizing
Imagine your home consumes 1,000 kWh per month.
How This Impacts Financing and ROI
If you buy an over-sized system via a bank loan, you are paying interest on solar panels that are generating surplus electricity that earns only a low export credit, some of which you may forfeit. This can extend your payback period.
To get the highest possible ROI under Solar ATAP, you must cap your system size.
How to Perfectly Size Your System
Do not rely on companies pushing maximum panel counts. Instead, size the system from your actual TNB data:
- Analyze Your Load Profile: Look at your TNB bill to understand exactly how many kWh you consume monthly.
- Factor in Daytime vs Nighttime: Solar only generates during the day. If you work in an office and only use AC at night, a massive solar system will export too much energy. In this scenario, size the solar system to your daytime use. A home battery (such as Huawei LUNA2000 or SolisStorage) can store the surplus, but battery payback is long and depends on how you use it, so compare both options before deciding.
- Use a Calculator: Trexon's calculator applies your RP4 tariff to Malaysian sun-hour data to recommend a system size.
Find Your Perfect System Size
Don't guess and don't let a salesperson over-sell you. Enter your TNB bill into our calculator and it will recommend a system size suited to the Solar ATAP rules.