Solar Under Net Billing: Why Daytime Self-Use Decides Your Payback
With exports bought cheaply, a 600-unit home's solar payback depends on how much power it uses in the day. Savings at 30%, 50%, 70% and 90% self-use.
By the TurantTools PK team · Updated 28 October 2026 · 2 min read
Since 9 February 2026, new solar users get net billing instead of net metering: the power you send to the grid is bought at a low price (around Rs 11 a unit), while power you take from the grid costs the full price. So what solar saves you depends on how much of the daytime power you use yourself.
A 4.5 kW system for a 600-unit home
| Used at home in the day | Saving a month | Payback (years) |
|---|---|---|
| 30% | Rs 13,058 | 3.2 |
| 50% | Rs 17,246 | 2.4 |
| 70% | Rs 21,435 | 1.9 |
| 90% | Rs 25,623 | 1.6 |
Going from 30% to 90% self-use roughly halves the payback, because every unit you use yourself saves the full grid price, while an exported unit earns far less.
How to use more daytime power
- Run the washing machine, iron and water motor around midday.
- Cool rooms with the AC in the afternoon so it runs less in the evening.
- If no one is home in the day, work out a smaller system or a battery separately.