- Use solar directly in the daytime first; exports are a secondary benefit.
- Ask your installer to model imports and exports separately, not as one-for-one unit swapping.
- Existing agreements need their date, approved capacity, and modification status checked before assuming the new rules apply.
- Payback can still be strong, but oversized systems designed mainly for export are harder to justify in 2026.
How this guide was prepared
SolarCalculator.com.pk explains the cited official documents and adds its own worked calculations. Examples state their assumptions and are illustrative; they are not measurements from customer installations. Dealer prices are dated snapshots and require a new written quote. This is independent publisher research, not an endorsement by the authorities or manufacturers linked below.
Quick answer
Net billing means your bill is calculated in rupees, not by simply cancelling every exported unit against every imported unit. In plain terms, you buy grid electricity at the applicable retail tariff and sell surplus solar electricity at the official export-credit basis defined by NEPRA. The two values can be very different.
This matters most for homes where everyone is away during the day and most load happens after sunset. A system that exports heavily at noon but imports heavily at night can look excellent in a one-for-one spreadsheet and only average under net billing.
What changed in 2026
NEPRA's Prosumer Regulations 2026 replaced the older distributed generation and net metering framework for new prosumer arrangements. The regulations define a prosumer as a consumer who connects a distributed generation facility, such as solar, to a distribution licensee's system.
The core billing clause says imported kWh from the licensee are billed under the applicable tariff, while exported kWh supplied by the prosumer are billed according to the national average energy purchase price. It also allows the net billed amount, when export credit exceeds import charges, to be carried forward or paid quarterly subject to the regulations and agreement.
Read the later amendments with the base regulations. April's amendment addresses existing-user protection; the August 6 amendment exempts DG facilities of 25 kW or less from NEPRA concurrence and assigns their approval to the distribution licensee. The practical point is to identify your capacity, agreement date and modification status before relying on a summary.
- New applicants should assume net billing unless the DISCO gives a different written treatment.
- Existing agreement holders should keep copies of the signed agreement, approval, concurrence/licence, and bills.
- Capacity changes, inverter changes, and other technical modifications should be cleared before work starts.
Evidence for this section: NEPRA Prosumer Regulations 2026, S.R.O. 251(I)/2026 · NEPRA Prosumer Regulations amendment, S.R.O. 547(I)/2026 · NEPRA S.R.O. 1330(I)/2026 small-system approval amendment
Import, export, and self-consumption
A solar system produces DC energy from panels, converts it to AC through the inverter, and feeds your house loads first when designed that way. If generation is higher than your live load, the surplus can flow to the grid through the approved metering arrangement. If your load is higher than solar generation, or if it is night, you import from the grid.
The best rupee value is usually the unit you never import. If your air conditioner, water pump, fridge, office equipment, washing machine, or shop load is running during solar hours, that solar unit replaces a retail unit. An exported unit earns only the export-credit value applicable to your arrangement.
| Energy flow | What happens | Payback effect |
|---|---|---|
| Solar used instantly at home | Reduces units imported from the grid | Highest value because it avoids retail tariff and related bill charges |
| Solar exported to DISCO | Recorded by bidirectional/approved meter | Lower value under net billing, useful but not the main payback driver |
| Grid imported at night | Billed under your applicable tariff | Reduces savings if daytime surplus was sold cheaply and night units are bought at retail |
Simple payback model for 2026
A useful 2026 payback sheet should split generation into three buckets: self-consumed solar units, exported solar units, and imported grid units. If your quote only multiplies total solar generation by a high retail tariff, it is hiding the net billing risk.
For a rough household model, start with monthly units from your bill, likely daytime load, likely system generation, and the export-credit assumption your installer is using. Then stress-test the result by reducing exports or lowering the export rate. If the project only works in the optimistic case, size down or add load shifting before buying more panels.
| Example line item | Conservative planning value | Why it matters |
|---|---|---|
| 5 kW monthly generation | 550-650 kWh before site losses | Depends on city, shade, season, tilt, dust, and inverter clipping |
| Self-consumption target | 55-75% for homes with daytime load | Higher self-consumption improves payback under net billing |
| Export value | Use the current DISCO/NEPRA basis, not a salesperson promise | Export credit is volatile and can be revised |
| Battery impact | Model separately | Batteries improve backup and self-use, but increase capital cost |
Worked example: the same 600 solar units, two household schedules
Assume household demand of 600 kWh/month and usable AC solar generation of 600 kWh/month. Compare 55% and 75% direct solar use, with no battery losses in this example. The shared calculator currently assumes Rs. 60/kWh avoided retail value and Rs. 8.13/kWh export value. They are planning inputs, not a statement of your notified tariff. Replace them with the values applicable to your bill and agreement.
Monthly benefit = directly used solar × avoided retail value + exports × export value. The remaining energy charge = imported units × retail value − export credit. Here the assumed installed cost is Rs. 800,000. Simple payback divides that cost by 12 times the monthly benefit; it assumes the month represents the annual average and excludes financing, taxes, fixed charges, seasonal variation, degradation, maintenance and component replacement.
- Moving 120 units from export to direct use adds 120 × (Rs. 60 − Rs. 8.13) = Rs. 6,224.4/month in this scenario.
- The array and total generation stay the same. A larger battery or array is not assumed in the second row.
- Use a 12-month generation and load profile before treating this simple calculation as an investment forecast.
| Direct use | Direct / export / import kWh | Monthly energy benefit | Remaining energy charge | Simple payback |
|---|---|---|---|---|
| 55% | 330 / 270 / 270 | Rs. 21,995.1 | Rs. 14,004.9 | 3.0 years |
| 75% | 450 / 150 / 150 | Rs. 28,219.5 | Rs. 7,780.5 | 2.4 years |
Evidence for this section: NEPRA Prosumer Regulations 2026, S.R.O. 251(I)/2026
How to improve payback after net billing
The new buying principle is to size for your own load profile, not for maximum export. A 7 kW system that matches daytime load can beat a 10 kW system that dumps surplus into the grid. This is especially true for homes with low weekday daytime usage.
Move controllable loads into solar hours where practical. Timers for water pumps, laundry, ironing, EV charging, office work, and some cooling can shift units from the import bucket to the self-consumption bucket. If backup matters, compare a hybrid inverter and lithium battery against the added payback period rather than treating the battery as free savings.
- Ask for a quote that shows panel-only cost, inverter cost, structure, protection gear, wiring, earthing, meter/application charges, and labor separately.
- Do not oversize above sanctioned load or above what the DISCO can approve on the local transformer.
- Use a conservative annual performance ratio and include dirty-panel months.
- Recalculate if you plan to add another AC, start a home office, or install a battery later.
Mistakes to avoid
The biggest mistake is comparing 2026 quotes using old net metering logic. The second biggest mistake is chasing the lowest Rs/W panel while ignoring inverter quality, structure, earthing, surge protection, and after-sales support. The third is signing a green-meter package without confirming who owns the DISCO filing responsibility.
A trustworthy installer should be able to explain how your imported and exported units will appear on the bill, what assumptions are used for export credit, what happens if the application is delayed, and what equipment is safe to run during an outage.
FAQ
Is net metering finished in Pakistan?
For new prosumer arrangements, NEPRA's 2026 framework uses net billing language. Many people still say net metering for the green-meter setup, but the cash calculation for new applicants should be treated as net billing unless your DISCO confirms otherwise in writing.
Are existing solar users protected?
Existing users should check the date and terms of their signed agreement and any later NEPRA/DISCO approval. NEPRA listed an amendment in 2026 addressing approvals, licences/concurrences, and agreements executed under the repealed regulations. Do not modify capacity or inverter equipment without written clearance.
What is the best solar size after net billing?
The best size is the one that maximizes daytime self-consumption without creating low-value surplus. For many homes, that means sizing from monthly units and daytime load, not simply filling the roof.