Lesco Net Metering Bill Calculation Export Import Units

Understanding Import and Export Units on a LESCO Green Meter

A green meter used with a solar net metering connection records electricity flowing in two directions. Import units represent electricity taken from the LESCO grid, while export units represent surplus solar electricity sent back to the grid.

Understanding this distinction is essential when checking a LESCO electricity bill. Your solar panels may generate electricity during the day, but your property can still draw electricity from the grid when solar generation is insufficient or household demand is higher.

What Are Import Units?

Import units are the electricity units your home or business receives from the LESCO distribution network. These units increase when your electrical appliances consume more electricity than your solar system is currently generating.

For example, consider a household using air conditioning, refrigerators, lights and other appliances during the evening. If the solar system is not generating enough electricity at that time, the remaining requirement comes from the grid. The electricity received is recorded as imported energy.

Import readings are important because they help determine how much grid electricity you have consumed during the billing period.

What Are Export Units?

Export units represent surplus electricity generated by your solar system and supplied to the grid. This can happen when solar panels produce more electricity than your property needs at that moment.

For example, your solar panels might generate more electricity than your household consumes during sunny daytime hours. Instead of using all the generated electricity on-site, the surplus can flow into the LESCO network through your approved net metering arrangement.

The green meter records this outward flow separately from imported electricity. Export readings are used to determine the electricity supplied to the grid and the applicable credit under your billing arrangement.

Import vs Export: Understanding the Difference

Meter information	Import units	Export units
Electricity direction	Grid to property	Property to grid
When it happens	When grid electricity is needed	When surplus solar electricity is available
What it represents	Electricity received	Electricity supplied
Billing purpose	Used to calculate import charges	Used to calculate applicable export credits

Important: Import and export units should not automatically be treated as having identical monetary values. The applicable billing arrangement and rates determine how imported electricity and exported electricity affect your final bill.

How to Calculate Monthly Import and Export Units from Meter Readings

To calculate monthly electricity units, compare the previous meter readings with the current readings. A bidirectional meter maintains cumulative readings, so the difference between two readings gives the units recorded during that period.

You should calculate import and export separately rather than combining the two figures immediately.

Step 1: Find Your Previous Import and Export Readings

Start with the previous month's meter readings. You can use the readings recorded on your earlier bill or another reliable meter-reading record.

Identify the following information:

• Previous import reading: The cumulative electricity imported from the grid.
• Previous export reading: The cumulative electricity exported to the grid.
• Previous reading date: The date associated with those readings.

Keep the import and export figures separate. If your meter displays additional registers, such as peak and off-peak readings, identify those separately as well.

Step 2: Read the Current Meter Figures

Check your green meter and record its current import and export readings. Make sure you identify the correct registers before writing down the numbers.

For an accurate comparison, use the same register categories as your previous readings. Comparing an import reading with an export reading will produce an incorrect calculation.

Step 3: Calculate Monthly Import Units

Use this formula:

Monthly Import Units = Current Import Reading − Previous Import Reading

For example, assume your previous import reading was 5,200 units and your current reading is 5,480 units.

Monthly import units = 5,480 − 5,200

Monthly import units = 280 units

This means your property received 280 units of electricity from the LESCO grid during the example billing period.

Step 4: Calculate Monthly Export Units

Use a separate calculation for exported electricity:

Monthly Export Units = Current Export Reading − Previous Export Reading

For example, assume your previous export reading was 2,100 units and your current reading is 2,430 units.

Monthly export units = 2,430 − 2,100

Monthly export units = 330 units

Your solar system therefore exported 330 units to the grid during this hypothetical billing period.

Worked Example: Monthly Import and Export Calculation

The following example combines both calculations to show how monthly meter readings can be interpreted.

Reading category	Previous reading	Current reading	Monthly units
Import	5,200	5,480	280
Export	2,100	2,430	330

Based on these hypothetical readings:

• Imported electricity: 280 units.
• Exported electricity: 330 units.
• Difference: 50 more export units than import units.

This difference is useful for understanding the direction of your electricity balance. However, it does not automatically mean that your electricity bill will be zero or that you will receive a payment for the difference. Monetary billing depends on the applicable import rates, export credit rates and other bill components.

What If Your Meter Has Peak and Off-Peak Registers?

Some electricity billing arrangements distinguish between peak and off-peak consumption. If your LESCO bill or meter displays separate registers, do not combine them without first checking how each category is recorded.

For example, you may need to calculate peak import units and off-peak import units independently:

• Monthly peak import = Current peak reading − Previous peak reading.
• Monthly off-peak import = Current off-peak reading − Previous off-peak reading.

Apply the same principle to any separately recorded export registers. Use the register labels and corresponding readings shown on your actual meter and electricity bill.

LESCO Net Metering Bill Calculation Formula

After calculating monthly import and export units, the next step is understanding how these figures affect your electricity bill.

A useful starting point is to calculate the cost of imported electricity separately from the credit associated with exported electricity. The two amounts can then be compared according to the billing arrangement applicable to your connection.

1. Calculate the Cost of Imported Electricity

The basic calculation is:

Import Electricity Cost = Imported Units × Applicable Import Rate

For example, if a hypothetical connection imports 280 units and its applicable rate is represented by R, the calculation is:

Import electricity cost = 280 × R

The actual amount depends on the applicable tariff and any relevant consumption categories. If peak and off-peak rates apply, calculate each category separately instead of using one combined rate.

2. Calculate the Credit for Exported Electricity

Exported electricity is considered separately when calculating the applicable export credit.

The basic calculation is:

Export Credit = Export Units × Applicable Export Credit Rate

Using the hypothetical example of 330 exported units and an export credit rate represented by E:

Export credit = 330 × E

The applicable export credit rate must be taken from the billing arrangement governing your connection. Do not assume it is equal to the import electricity rate.

3. Calculate the Net Energy Amount

Once the import cost and export credit have been calculated, compare the two amounts:

Net Energy Amount = Import Electricity Cost − Export Credit

This calculation helps explain the monetary effect of imported and exported electricity.

For example, if the import electricity cost is represented by 280R and the export credit by 330E, the calculation becomes:

Net energy amount = 280R − 330E

This is a conceptual calculation, not a confirmed LESCO bill total. The actual result depends on the applicable rates, billing rules and treatment of credits.

4. Consider Other Electricity Bill Components

Your final LESCO electricity bill may contain components beyond the calculated import cost and export credit. Depending on the applicable tariff and billing arrangement, these can include:

• Fixed or other applicable service charges.
• Applicable electricity-related taxes and duties.
• Adjustments appearing on the billing statement.
• Previous outstanding amounts or other applicable bill entries.

Therefore, the net energy amount should not be confused with the final payable amount. Check the actual bill for the treatment of each charge and credit.

Net Metering vs Net Billing: Why Your Calculation Method Matters

Before calculating your LESCO net metering bill, identify which billing arrangement applies to your connection. Net metering and net billing are not interchangeable terms. They can treat imported electricity and exported electricity differently, so using the wrong calculation method may produce an incorrect estimate. Under a net metering arrangement, the calculation focuses on the relationship between electricity imported from the grid and electricity exported from your solar system. Depending on the applicable agreement and billing rules, eligible exported units may be adjusted against imported units. Under a net billing arrangement, imported and exported electricity may be accounted for separately. Electricity taken from the grid is calculated as consumption, while electricity sent back to the grid is accounted for under the applicable export compensation arrangement.

How to Identify the Applicable Arrangement

Check your net metering agreement, connection documentation and current billing information. Do not assume that every green meter connection follows the same calculation method. Pay attention to:

• Connection and agreement details: Review the arrangement approved for your solar connection.
• Connection date: Use it as supporting information when checking which regulatory and contractual provisions apply.
• Billing treatment: Check whether imported and exported electricity are adjusted against each other or calculated separately.
• Applicable rates: Identify the import tariff and the export credit or compensation rate relevant to your arrangement.

A simple difference between import and export units does not necessarily represent the final billable units. For example, if a hypothetical connection imports 400 units and exports 250 units, the difference is 150 units. However, that does not automatically mean LESCO will charge for exactly 150 units. The applicable billing arrangement, tariff components and other charges must also be considered. If your agreement or bill does not clearly explain the treatment of exported electricity, seek clarification from LESCO before relying on a net-unit calculation.

How to Compare Your Calculation with the LESCO Electricity Bill

Once you have recorded your green meter readings and identified the applicable billing arrangement, compare your figures with the corresponding LESCO electricity bill. The purpose is to understand how the monthly readings have been used, rather than expecting every bill amount to match a simple import-minus-export calculation.

Step 1: Find Last Month's Meter Figures

Start with the previous billing period. Record the closing import and export readings from the last available bill or meter record. You need separate figures for each applicable register. If your meter records peak and off-peak electricity separately, keep those readings separate as well.

Step 2: Read the Current Meter

Record the latest readings from your green meter. Make sure you identify the correct import and export registers. Use the following calculation:

Imported units = Current import reading − Previous import reading

Exported units = Current export reading − Previous export reading

For example, consider these hypothetical readings:

Register	Previous reading	Current reading	Monthly units
Import	2,400	2,850	450
Export	1,100	1,390	290

Your recorded monthly import is 450 units, while your export is 290 units.

Step 3: Check Peak and Off-Peak Registers

If your meter and bill provide separate peak and off-peak readings, calculate each register independently. For example:

Register	Imported units
Peak	180
Off-peak	270
Total import	450

Do not automatically combine peak and off-peak units when checking tariff-based charges. The applicable tariff may treat these consumption categories differently. Also check whether export readings are displayed as separate registers or whether the bill provides a consolidated export figure.

Step 4: Compare the Import and Export Figures

For a basic reading comparison, subtract exported units from imported units:

Net unit difference = Imported units − Exported units

Using the hypothetical readings above:

450 − 290 = 160 units

The result is a positive difference of 160 units. It represents the difference between the recorded import and export quantities, not necessarily the final units or amount charged by LESCO. If exported units exceed imported units, the difference is negative. Do not automatically interpret this as a cash refund or assume that the entire difference will carry forward. Check the applicable agreement and billing rules.

Step 5: Review the LESCO Bill Amount

Compare your working figures with the electricity bill. Look for the following information where available:

• Previous and current meter readings.
• Imported electricity units.
• Exported electricity units.
• Peak and off-peak consumption.
• Applicable electricity tariff.
• Export credit or adjustment details.
• Other applicable charges, taxes and adjustments.

If your bill shows imported and exported electricity separately, compare each figure with your own meter calculation. If the bill shows only an adjusted amount, check the billing arrangement before deciding that a discrepancy exists. You can also download your LESCO bill online to keep a copy for comparison.

What If Your Calculation Does Not Match the Bill?

A difference does not always indicate a faulty meter. First, check whether you and LESCO are using the same billing period. Consider these possible explanations:

• Different reading dates: Your manual reading may cover a different period from the official meter reading.
• Incorrect register: You may have recorded a total reading instead of the specific import or export register.
• Peak and off-peak treatment: Combining registers can make a tariff-based comparison inaccurate.
• Billing adjustments: The bill may include previous adjustments or other applicable amounts.
• Export credit treatment: The export calculation may follow a different rate or adjustment method from your estimate.

If the difference remains unexplained, keep photographs of the meter readings and copies of the relevant bills. Contact LESCO with your reference number and ask for an explanation of the imported units, exported units and billing adjustments.

Common Mistakes When Calculating LESCO Net Metering Units

Even when the meter readings are correct, small calculation mistakes can lead to an inaccurate estimate. Check these issues before comparing your figures with the LESCO electricity bill.

1. Subtracting Export Units from the Wrong Import Reading

Always calculate the monthly change in each register separately. Do not subtract the previous export reading from the current import reading. Import and export are different measurements and must remain separate throughout the calculation.

2. Using the Total Meter Reading as Imported Units

A green meter may display several readings. The total display should not automatically be treated as imported electricity. Identify the specific register representing electricity taken from the grid.

3. Ignoring Peak and Off-Peak Consumption

If your connection has separate time-based registers, preserve those categories. Combining them too early can hide differences in the applicable electricity charges.

4. Assuming Every Exported Unit Cancels One Imported Unit

This is one of the most important mistakes to avoid. The import-export unit difference is not necessarily the final billable quantity. The applicable arrangement determines how exported electricity is treated.

5. Applying the Same Rate to Import and Export

Do not assume that the price charged for imported electricity is identical to the compensation or credit applied to exported electricity. Use the rates applicable to your agreement and billing period.

6. Comparing Different Billing Periods

Your manual readings and the LESCO bill must cover comparable periods. A reading taken several days before the official billing date can produce different unit totals.

7. Forgetting Other Bill Components

Even if your estimated electricity adjustment is correct, the payable amount may include other applicable charges, taxes, duties or previous adjustments. Therefore, a unit calculation alone cannot establish the complete payable bill.

8. Treating a Negative Unit Difference as a Guaranteed Refund

Exporting more electricity than you import does not automatically establish a cash payment. Check the applicable export credit, adjustment and settlement provisions before estimating any financial benefit.

9. Ignoring an Unusual Meter Reading

If a register appears unchanged, decreases unexpectedly or shows an unusually large difference, verify the display and reading date. If the problem persists, request a meter-reading check rather than changing the figures manually.

Conclusion

Calculating LESCO net metering units starts with two separate measurements: electricity imported from the grid and electricity exported by your solar system. Subtract the previous reading from the current reading for each register, preserve peak and off-peak figures where applicable, and identify the billing arrangement before estimating the adjustment. For your next billing cycle, record your green meter readings on the official reading date and compare them with the corresponding LESCO electricity bill. If the figures or export credit remain unclear, request a billing explanation from LESCO instead of relying on a simple net-unit difference.