Net Metering Calculator

Estimate how much electricity your solar system can generate, how much you can use directly, and how much can be exported to the grid.

Enter your solar system size, monthly power consumption, peak sun hours, efficiency ratio, electricity tariff and export rate. The calculator will estimate monthly solar production, self-consumption, exported electricity, grid credit and overall financial benefit.

The calculator helps you compare different solar and electricity usage scenarios. Your actual electricity bill may vary due to time of use, tariff structure, fixed charges, taxes, adjustments and billing arrangements that apply to your connection.

What does the net metering calculator show?

The calculator breaks down your solar power into key areas that are important for a grid-connected system.

Generating electricity from solar energy

This is the approximate amount of electricity your solar system can generate based on:

•  Size of the solar system
•  Peak sun hours
•  Performance ratio

Generation is measured in kilowatt hours (kWh), also commonly referred to as units of electricity.

Self-consumption from solar energy

Self-consumption is the portion of solar electricity that is used directly in your home or business. For example, if your solar panels are generating electricity while your fans, air conditioners, machinery or other appliances are running, some of that solar energy can be used directly instead of being supplied from the grid.

The calculator estimates self-consumption from your monthly generation and consumption data. Actual self-consumption depends heavily on when you use electricity, so your actual result may vary.

Electricity was exported to the grid.

When your solar system produces more electricity than is used on the property, the excess electricity can be exported to the grid where applicable connection and billing arrangements allow it.

The calculator estimates this amount as follows:

• Solar generation − estimated self-consumption = exported electricity

Estimated grid credit

The exported electricity may have a monetary value based on the export rate applied to the connection. The basic calculation is:

• Exported electricity × Export rate = Estimated grid credit

For the new consumer arrangements under Pakistan’s 2026 regulations, imported and exported electricity are treated separately under the applicable net billing framework.

Estimated solar gain

The calculator combines these factors to determine your estimated solar savings:

• Solar electricity used directly on the property
• Solar power credit exported to the grid

This distinction is important because electricity used directly may have a different monetary value than electricity exported.

How to use the net metering calculator?

1. Enter the size of your solar system.

Enter the total DC capacity of your solar panel system in kilowatts.

For example:

• 5 = 5 kW solar system
• 10 = 10 kW solar system

Use your actual or proposed solar panel capacity instead of your monthly electricity consumption.

2. Enter your monthly electricity consumption.

Check your electricity bill and enter your consumption in kWh or units. If your electricity usage varies significantly throughout the year, review several bills instead of relying on one unusually high or low month.A 12-month consumption history can provide an even clearer picture of your typical electricity needs.

3. Enter the daily peak sun hours.

Enter realistic peak sun times for your location. Peak solar hours are different from total daylight hours. They represent the equivalent number of hours during which the day’s solar energy will be equal to full solar radiation.

The availability of solar energy varies:

•  Location
•  Weather
•  Weather
•  Panel orientation
•  Panel tilt
•  Shading

Use location-specific solar data where possible.

4. Set the performance ratio.

The efficiency ratio accounts for the difference between theoretical solar panel output and expected real-world generation.

What can reduce solar energy production?

Common damages can be caused by:

•  Inverter replacement
•  Electrical wiring
•  High panel temperature
•  Dust and dirt
•  Shading
•  Equipment performance
•  Other disadvantages of the system

Use the appropriate efficiency ratio for the system you are evaluating rather than assuming the panels will always operate at their full rated output.

5. Enter your electricity tariff.

Enter the price of electricity you want to use per kilowatt hour when estimating the cost of solar electricity used directly on your property. A recent electricity bill is usually the most useful starting point. Remember that your full bill may also include taxes, fixed charges, and other adjustments that are not represented by the per-kilowatt-hour figure.

6. Enter the solar export rate.

Enter the rate applicable to the electricity exported to the grid from your solar system. Under Pakistan’s 2026 Prosumer Framework, electricity imported from the utility and electricity exported by the prosumer are valued separately for the new arrangements included in these regulations.

The National Average Energy Purchase Price (NAEPP) in NEPRA’s CY2026 determination is Rs. 8.13/ kWh.

You should check your own contract and the regulations applicable to your connection before relying on a particular export rate.

7. Calculate your results.

Select Calculate Net Metering to see your estimate :

•  Solar generation
•  Direct use of solar energy
•  The electricity was exported to the grid.
•  Export credits.
•  Monthly financial benefit
•  Annual financial benefit

If you want to enter another scenario, use Reset .

How is net metering calculated?

The calculator uses your solar system, electricity consumption and financial information to estimate production, self-consumption and exports.

Step 1: Calculate solar generation.

The formula is:

• Solar generation = System size × Peak sun hours × 30 × Efficiency ratio

For example, suppose you have:

• System size: 5 kW
• Peak sun hours: 5.5/day
• Efficiency ratio: 0.80

The estimated monthly generation will be:

• 5 × 5.5 × 30 × 0.80 = 660 kWh

Step 2: Estimate your own solar energy consumption.

The calculator uses:

• Self-consumption = MIN (solar production, monthly consumption)

If the production is 660 kWh and the monthly consumption is 600 kWh:

• MIN(660, 600) = 600 kWh

This is a monthly calculation.

Why might actual self-consumption be different?

When electricity is used, the monthly total is not displayed. For example, a household may use 600 kWh over the course of a month but uses most of that electricity after sunset.

In this situation, the actual daytime solar energy self-consumption may be lower than the monthly calculation. A business that operates primarily during daylight hours may have a very different self-consumption pattern even if its total monthly electricity usage is the same.

Step 3: Calculate solar export.

The calculator subtracts estimated self-consumption from solar generation:

• Exported electricity = Solar generation – Self-consumption

Using the previous example:

• 660 − 600 = 60 kWh exported.

Step 4: Calculate the export credit.

The basic calculation is:

• Exported kWh × Export Rate = Estimated Grid Credit

If 60 kWh is exported at Rs. 8.13/kWh:

• 60 × 8.13 = Rs. 487.80

Step 5: Calculate the estimated financial benefit.

The calculator combines:

• Price of solar electricity directly used + price of exported electricity

Since the financial values of direct solar use and exported solar electricity may differ, they should be considered separately.

Net metering vs net billing in Pakistan

Net metering is widely used when people talk about rooftop solar, green meters, and exporting electricity to the grid. They have introduced a net billing arrangement for customers covered under the new framework .

How does net billing work?

Under the 2026 framework: Electricity supplied by the utility to consumers is billed at the applicable consumer tariff. The electricity supplied by the consumer to the utility is collected according to the applicable national average energy purchase price. This means that imported and exported electricity are not automatically priced the same.

What about current solar contracts?

Existing contracts may be treated differently by new promissory notes arrangements. NEPRA issued amendments to the Prosumer Regulations during 2026 relating to contracts concluded under the previous framework.

If you already have a contract, use the billing method and rate that legally applies to your specific contract rather than automatically applying the rate used for the new promoter. For existing installations, verify the current position with your contract documents, relevant DISCO and latest NEPRA regulations before making financial calculations.

Net metering calculation example

Consider a 5 kW solar system with the following inputs:

Input	Value
Size of the solar system	5 kW
Monthly electricity consumption	600 kilowatt-hours
Peak sun hours	5.5/day
Performance ratio	0.80
Electricity price	Rs. 40/kWh
Export rate	Rs. 8.13/kWh

Calculate monthly solar generation.

• 5 × 5.5 × 30 × 0.80 = 660 kWh

Estimated generation:

• 660 kWh per month

Calculate estimated self-consumption.

• MIN(660, 600) = 600 kWh

Estimated self-consumption:

• 600 kilowatt-hours

Calculate the electricity exported.

• 660 − 600 = 60 kWh

Estimated export:

• 60 kilowatt-hour

Calculate export credit.

• 60 × 8.13 = Rs. 487.80

Estimated export credit: Rs. 487.80

Calculate the combined monthly value.

Estimated self-consumed electricity cost:

• 600 × 40 = Rs. 24,000

Add estimated export credit:

• Rs. 24,000 + Rs. 487.80 = Rs. 24,487.80

Estimated combined monthly cost: Rs. 24,487.80

This example follows the calculator’s monthly calculation method. Your actual bill may vary because actual self-consumption, tariffs, taxes, fixed charges, and other billing items are not determined by these inputs alone.

Why solar self-consumption matters.

Not every solar unit has the same financial value. The electricity used directly while your solar system is generating can reduce the amount of electricity you need to purchase from the grid. Electricity exported to the grid can be credited at different rates. Therefore, increasing direct daytime usage can change the financial results of a solar installation.

Devices that you may be able to use during solar power hours.

Depending on your home or business, flexible loads may include:

•  Washing machines.
•  Water pumps
•  Electric water heating
•  Merchandise
•  Other devices that do not need to work at a set time.

The best approach depends on your actual electricity usage patterns and appliances.

What affects your net metering results?

Actual solar production and financial savings may differ from the calculator results due to several factors.

Daytime electricity usage

Monthly electricity consumption does not tell you when that electricity was used. A property with strong daytime consumption can use more solar directly. A property with a lot of evening or nighttime consumption may rely heavily on grid electricity even if it has a high monthly solar output.

Size of the solar system

A larger solar system may produce more electricity, but increasing the size of the system does not automatically mean that each additional unit will have the same financial value. Once the day’s demand is met, more electricity can be exported.

Peak sun hours

Solar resources vary depending on location and season. Using realistic peak sun times is important when estimating breeding.

System performance

Dust, temperature, wiring, inverter performance, shading, and equipment condition can all affect solar output.

Electricity tariff

The tariff used in the calculation directly affects the estimated cost of solar electricity used.

Export rate

The export credit rate directly affects the value assigned to the electricity supplied to the grid. Therefore, regulatory changes can have a significant impact on financial projections.

How to get a better net metering estimate.

Start with real information from your property wherever possible.

Use several months of electricity bills.

Don’t rely on any one month if your consumption changes significantly throughout the year.

Use realistic peak sun times.

Use solar resource information appropriate for your city or site.

Add real-world system disadvantages.

Set a realistic efficiency ratio instead of calculating generation from the rated panel capacity alone.

Check your daytime electricity usage.

Think about when major appliances and equipment work. This can give you a better idea of how much solar power can be used directly.

Check the export rate that applies to you.

Don’t automatically use the normal export rate. The exact rate depends on the terms and conditions applicable to your connection.

What is not included in the net metering calculator?

This calculator estimates solar energy production, direct use, exports, and their monetary value. It does not reproduce the official electricity bill of the disco. The calculation does not include every possible billing component individually, such as:

•  Fixed charges
•  Fuel adjustment
•  Quarterly adjustment
•  Meter charges
•  Duties
•  Tax
•  Outstanding balances
•  Other items with specific bills

It doesn’t even know about your property:

•  Precise hourly load profile
•  Detailed shading
•  Roof orientation
•  Inverter behavior
•  Grid shutdown
•  Inverter trimming
•  Equipment failure
•  Maintenance status

These factors may cause actual solar production and electricity bills to differ from estimates.

Who should use the net metering calculator?

This calculator can help:

•  Homeowners are considering grid-connected solar power.
•  Existing solar customers are reviewing export assumptions.
•  Businesses comparing proposed solar systems
•  Property owners are comparing the sizes of different systems.
•  Buyers are reviewing solar quotations.
•  Consumers comparing different electricity and export tariffs

This is especially useful when you want to see how changing one input affects generation, own consumption, exports, and estimated savings.