A common misconception we hear from new solar customers is that selling excess power back to the grid is where the real savings come from. In reality, the math works the opposite way: using the power your panels generate, right when you generate it, is worth almost double what selling it back pays. This article breaks down why, using this year's confirmed rates.
The two rates, side by side
| Rate | Value | What it means |
|---|---|---|
| Retail electricity (what you pay PEA/MEA) · ค่าไฟขายปลีก (ที่จ่ายให้ กฟภ./กฟน.) | ≈ ฿3.95/kWh (Jun–Aug 2026, Ft +฿0.1623/unit) · ≈ 3.95 บาท/หน่วย (มิ.ย.–ส.ค. 2569, Ft +0.1623 บาท/หน่วย) | This is what every unit of power costs you if you buy it from the grid. · นี่คือราคาที่คุณต้องจ่ายทุกหน่วยไฟที่ซื้อจากกริด |
| Sell-back rate (2026 program) · ราคาขายไฟคืน (โครงการปี 2569) | ฿2.20/kWh, 10-year contract · 2.20 บาท/หน่วย สัญญา 10 ปี | This is what you're paid per unit for excess solar power exported to the grid. · นี่คือราคาที่คุณได้รับต่อหน่วยไฟส่วนเกินที่ส่งออกให้กริด |
| Difference · ส่วนต่าง | ≈ ฿1.75/kWh · ≈ 1.75 บาท/หน่วย | The gap between what you'd pay to buy that unit vs. what you're paid to sell it. · ส่วนต่างระหว่างราคาที่ต้องจ่ายซื้อกับราคาที่ได้รับจากการขาย |
Retail rate reflects the ERC-announced average for Jun–Aug 2026. Confirm your current bill's actual rate, as it varies by usage tier and time-of-use plan.
Every unit (kWh) of solar power you use directly instead of drawing from the grid saves you ฿3.95. If instead that same unit is exported and sold back, you only earn ฿2.20 — and you'd still need to buy back a replacement unit from the grid at ฿3.95 whenever you need power your panels aren't producing (like at night). Self-use avoids that round trip entirely.
What this means for your system design
- Size your system to match your daytime usage pattern first — AC, pool pumps, and appliances running while the sun is up capture the full ฿3.95 value.
- Only genuine leftover power — what you can't use yourself even after covering daytime needs — should be exported under the sell-back program.
- A battery can shift self-use even further, storing daytime solar power to use again at night instead of exporting it at the lower rate — though the battery's own cost needs to be weighed against that benefit (see our related article on solar + battery storage).
The sell-back program (see our related article) is still worth applying for — it's free money for power you genuinely can't use. Just don't let it be the main reason you decide how big to build your system.
We size every system around your actual usage pattern first, so you capture the full ฿3.95 self-use value before anything gets exported. Book a free consultation to see what system size makes sense for your home.
Frequently Asked Questions
Should I skip the sell-back program entirely and just focus on self-use?
No — the two aren't mutually exclusive. Design your system to maximize self-use first, then apply to sell back whatever genuine excess remains within the 5 kW export cap. Skipping the program just leaves that leftover power unmonetized.
Does this math change if I get a battery?
A battery shifts more of your solar power into the ฿3.95 self-use category by storing it for nighttime use instead of exporting it at ฿2.20. It can improve the economics further, but the battery itself has an upfront cost that needs to be weighed against your usage pattern.
Will the ฿3.95 retail rate stay the same?
The Ft component of the retail rate is reviewed and adjusted periodically by the ERC, so the exact figure can shift every few months. The ฿3.95 figure reflects the announced average for June–August 2026 — check your current bill or the ERC's announcements for the latest rate.