Solar Net Billing (Buyback) Calculator 2026

Understanding Solar Net Billing in 2026

For years, Pakistan's solar industry thrived under a simple Net Metering regime. It was a straightforward 1:1 exchange: if you exported 10 units during the day and imported 10 units at night, your net bill for those units was zero. However, in early 2026, the National Electric Power Regulatory Authority (NEPRA) shifted the framework to Net Billing.

This shift was driven by the need to stabilize the national grid and ensure that solar owners contribute to the maintenance of the transmission infrastructure. Under Net Billing, the "Sell" rate and the "Buy" rate are no longer the same, which fundamentally changes how you should calculate your Return on Investment (ROI).

How the Calculator Works

Our Solar Net Billing Calculator uses the latest 2026 tariff data to provide an accurate estimate of your monthly savings. To get the most out of the tool, you need to understand the four primary variables it tracks:

1. Total Monthly Generation (kWh)

This is the total amount of energy your solar panels produce. A well-optimized 5kW system in Pakistan typically produces between 600 and 750 units per month, depending on the season and city (Karachi and Multan generally see higher yields than Islamabad or Peshawar).

2. Self-Consumption Percentage

This is the most critical metric in 2026. Self-consumption refers to the energy generated by your panels that is used immediately by your appliances without ever reaching the grid.

• If you use 1 unit directly from solar, you save Rs. 60 (the average grid import rate).
• If you export that same unit, you only earn Rs. 11.50 (the buyback rate). Maximizing this percentage is the key to minimizing your bill.

3. Grid Import Rate (The "Buy" Price)

In 2026, the retail price of electricity in Pakistan has reached historic highs. Between base tariffs, Fuel Price Adjustments (FPA), and various surcharges, most residential consumers in the "Protected" or "Unprotected" slabs are paying between Rs. 55 and Rs. 70 per unit.

4. Export Buyback Rate (The "Sell" Price)

The export rate is determined by NEPRA based on the national average power purchase price. For 2026, this rate hovers around Rs. 11.35 to Rs. 12.50. This is the credit you receive for surplus energy sent back to the grid.

Step-by-Step Manual Calculation Example

Let's assume you have a 10kW system in Lahore during the month of May:

1. Total Generation: Your system produces 1,200 units.
2. Self-Consumption (40%): You use 480 units directly during the day (Running ACs and fans).
   • Savings: 480 units × Rs. 60 = Rs. 28,800 saved.
3. Surplus Export (60%): You send the remaining 720 units to the grid.
   • Credit: 720 units × Rs. 11.50 = Rs. 8,280 credit.
4. Night-time Consumption: You import 500 units from the grid at night.
   • Cost: 500 units × Rs. 60 = Rs. 30,000 cost.
5. Net Result:
   • Grid Cost (Rs. 30,000) - Solar Credit (Rs. 8,280) = Rs. 21,720 payable.
   • Total Bill without Solar: (480 + 500) × Rs. 60 = Rs. 58,800.
   • Total Actual Monthly Savings: Rs. 58,800 - Rs. 21,720 = Rs. 37,080.

Strategies for the Net Billing Era

To maximize your benefits in 2026, we recommend the following adjustments:

Load Shifting (The Noon Peak)

Instead of running heavy loads like water pumps, laundry machines, or electric irons in the morning or evening, schedule them for between 11 AM and 2 PM. This ensures you are using "free" solar power worth Rs. 60/unit rather than selling it for Rs. 11/unit.

Thermal Storage

Use excess daytime solar to heat your water via electric geysers or to over-cool your home (thermal banking) during the last few hours of peak sunlight. This reduces the energy needed from the grid once the sun goes down.

Consider a Hybrid Transition

If your export credits are too low to cover your nighttime imports, 2026 is the year to consider adding a small 5kWh Lithium (LFP) battery. Storing just 5 units of daytime energy for use at night is worth Rs. 300 per day (5 units × Rs. 60), which is much better than exporting those 5 units for a measly Rs. 57 (5 units × Rs. 11.5).

Use our Solar Net Billing Calculator to input your specific DISCO rates and generation data for a precise 2026 forecast.