One of the most misunderstood aspects of Malaysia's Solar ATAP program is how it handles unused export electricity credits. Unlike the previous Net Energy Metering (NEM) scheme, which carried credits forward, Solar ATAP does not carry credits over: any export credit that is not used against your bill by the end of the billing period is forfeited (SEDA guideline GP/ST/No.60/2025, s.3.6.1(b)).
This is not a minor technicality. It changes the best strategy for system sizing, when to run your appliances, and whether a battery storage system makes financial sense.
NEM vs Solar ATAP: Credit Carry-Forward Comparison
| Feature | Old NEM 3.0 | Current Solar ATAP |
|---|---|---|
| Export rate | Exported kWh offset against imported kWh | Homes: Energy Charge, RM 0.2703/kWh (RM 0.3703 above 1,500 kWh a month); businesses: monthly Average SMP |
| Credit carry-forward | Credits carried forward | None: forfeited at the end of each billing period |
| Contract length | Per NEM terms | Up to 10 years |
| Bill offset mechanism | Credited against retail electricity bill | Credited against retail electricity bill |
| Oversizing risk | Low (credits accumulate) | High (excess credit is wasted) |
| Battery benefit | Moderate | Modest: stored energy is worth the avoided grid charge, but battery price is much larger than the credit at stake |
Why the Billing-Period Reset Matters
Here is a concrete example. Imagine an 8.06 kWp system (RM 21,499, Solis) that generates about 846 kWh a month. In a month when the family is travelling, the household uses only 450 kWh.
What happens to the excess credit?
- Your bill before solar would be about RM 137 (450 kWh on the RP4 tariff, before AFA and service tax)
- About 339 kWh is used at home, so you still import 111 kWh from the grid (about RM 50 before any credit)
- About 508 kWh is exported, but the credit is capped at the 111 kWh you imported: about RM 30 of credit at RM 0.2703/kWh, leaving a bill of about RM 19 (capacity, network and other charges are not offset)
- The other 396 kWh of export earns nothing, so about RM 107 of credit is forfeited
- Under the old NEM: the leftover credit could carry forward to next month
- Under Solar ATAP: the leftover credit disappears at the end of the billing period
The Real Cost of Forfeiture: If 200 kWh of exported energy goes unused every month, you lose about RM 54 a month (200 x RM 0.2703), roughly RM 649 a year, in value that simply evaporates.
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.
How to Calculate Your Credit Waste Risk
To estimate whether you have a credit waste problem, compare your solar generation against your consumption, month by month. The risk is highest in these scenarios:
1. Oversized Systems (Most Common Issue)
Many installers recommend systems sized to generate 100% or more of your annual consumption. This looks good on paper but ignores monthly variation. A system that meets your annual needs will still overproduce in low-consumption months (holidays, travel) and underproduce in high-consumption months.
Practical guideline: Under Solar ATAP without a battery, size your system to your daytime use rather than to 100% of your consumption, to limit credit waste.
2. Vacation Homes and Frequent Travellers
If you travel frequently for more than one week per month, your consumption during those months drops significantly while your panels keep generating at full capacity. Every kWh generated while the house is empty is either exported (at RM 0.2703) or, if you export more kWh than you import, simply wasted.
3. Retirees and Work-from-Home Transitions
A system sized for a dual-income household with two adults away during business hours will be oversized if one partner retires or shifts to working from home. Higher daytime self-consumption helps, but you may have installed a larger system than needed.
Month-Type Scenarios: The Cost of No Battery
The same 8.06 kWp system (about 846 kWh a month) behaves very differently depending on how much you use in the month:
| Month type | Usage (kWh) | Bill before solar | Export credit earned | Credit forfeited | Bill after solar |
|---|---|---|---|---|---|
| Travel month | 350 | RM 83 | RM 3 | RM 134 | RM 2 |
| Low-use month | 450 | RM 137 | RM 30 | RM 107 | RM 19 |
| Normal month | 700 | RM 277 | RM 98 | RM 40 | RM 64 |
| Busy month | 1,000 | RM 464 | RM 137 | RM 0 | RM 152 |
In low-use months most of the credit is forfeited, not because the system is badly designed, but because credit can only offset the kWh you import. Months with higher use absorb every credit.
Where a Battery Fits Under Solar ATAP
The billing-period reset changes the battery calculation. Under the old NEM scheme, a battery's main value was backup power. Under Solar ATAP, a battery has another function: preventing credit forfeiture.
How a Battery Reduces Credit Waste
Instead of exporting excess daytime generation at RM 0.2703/kWh, a battery stores it and releases it in the evening, when you would otherwise buy from the grid at RM 0.4443/kWh (RM 0.5443 above 1,500 kWh a month). The value of stored energy is the avoided grid charge, not the export rate.
| Strategy | Value Per Excess kWh | Monthly Value (200 kWh excess) | Annual Value |
|---|---|---|---|
| Export to TNB (no battery) | RM 0.2703/kWh | RM 54 | RM 649 |
| Store in battery (evening use) | RM 0.4443/kWh | RM 89 | RM 1,066 |
| Credit forfeiture (no battery, low-use month) | RM 0/kWh | RM 0 | RM 0 |
A battery converts wasted credit into evening energy worth about 1.6 times the export rate. Weigh that gain against the battery price, which is much larger than the credit at stake in most homes. For full details on battery options and costs, see our guide: Solar Battery Storage Malaysia 2026: Complete Buyer's Guide.
Practical Steps: What to Do Right Now
If You Already Have Solar ATAP Without a Battery
- Download your last 12 months of TNB bills from the myTNB app
- Note your Solar ATAP credit each month (shown as a deduction on your bill)
- Check whether low-use months show a very small bill while your system exported far more than you imported: this indicates you are forfeiting value
- Compare the value of the forfeited credit with the cost of a battery before you decide
If You Are Planning a New Solar System
- Do not size your system to generate 100%+ of annual consumption under Solar ATAP without a battery: you will waste credits in low-consumption months
- Choose the inverter topology with your storage plan: solar-only Solis uses a grid-tied string inverter, while compatible storage includes the required hybrid inverter scope
- Read our full guide on our full Solar ATAP guide before finalizing your system design
Summary: Key Takeaways on ATAP Credit Reset
- Solar ATAP credits do not carry over: unused credit is forfeited at the end of each billing period, unlike the old NEM scheme, which carried credits forward
- Unused credits are not paid out
- The reset makes proper system sizing important: oversizing wastes value
- A battery reduces credit waste and makes each stored kWh worth about 1.6 times the RM 0.2703/kWh export credit
- Choose a hybrid inverter when compatible battery storage is part of the design; solar-only Solis packages begin with a grid-tied string inverter
Contact Trexon's consultants for a month-by-month credit analysis based on your actual TNB bills. You can also run your own numbers using our solar savings calculator. For full program details including quota availability and eligibility, see the Solar ATAP program page.
