Claire WhitakerBy Claire Whitaker

Updated November 2026

The ComEd net metering program lets Northern Illinois homeowners with rooftop solar send excess electricity back to the grid and receive credits on their monthly bill. This guide walks you through eligibility, the application process, how credits are calculated, and the mistakes that delay or shrink those credits. By the end, you should know what paperwork to prepare and what to check on your statement once your system is running.

Note that net metering rules, rates and program terms can change. Confirm current details with ComEd and the Illinois Commerce Commission before you commit to a system design or financing.

Shopping for one? See our guide: Net Metering Solar Program vs Self-Consumption: Which Is Better for Homeowners?.

What the ComEd Net Metering Program Covers

ComEd, the utility serving much of northern Illinois, allows eligible customers with on-site generation to connect to the distribution grid. When your panels produce more electricity than your home uses at a given moment, the surplus flows to the grid and is measured by your meter. When your home draws more than your panels produce, such as at night, you pull from the grid as usual. Over a billing period, the utility nets these flows against each other.

Illinois law sets the framework for these arrangements, and ComEd administers them for its customers. The practical result is that you are billed for your net usage rather than your gross usage, provided your system meets the program’s technical and interconnection requirements.

Step 1: Confirm Your Eligibility

Before you buy anything, check whether your situation fits the program. Most residential installations that qualify share a few traits:

  • Your home is served by ComEd and you are the account holder on the electric service.
  • The system is intended to offset your own consumption, not to act as a commercial generation plant.
  • The inverter and equipment meet the interconnection standards that ComEd and state rules require.
  • The system is sized reasonably relative to your historical annual usage. Oversizing can lead to a review and sometimes a different compensation structure.

Pull at least twelve months of your ComEd bills before you talk to an installer. Those bills show your average monthly kilowatt-hour (kWh) use and seasonal peaks, which are the numbers you need to size the array correctly.

Step 2: Size the System to Your Usage

A rough sizing method works well for planning. Divide your annual kWh use by the expected production of one kilowatt of solar capacity in your area, then adjust for shading and roof orientation. Northern Illinois typically yields a moderate annual output per installed kilowatt, lower than sunnier southern states, so sizing to a large share of your usage often means a larger array than you might expect.

Installers normally run a production estimate using modeling software. Ask for the estimated annual output in kWh and compare it to your actual usage. An array that produces far more than you consume in a year can still be approved, but the surplus credit handling matters more in that case, which is covered below.

Step 3: Gather the Application Documents

The interconnection application is the gateway to net metering. Most applications ask for similar information, so gather these items first:

  1. Your ComEd account number and the service address.
  2. A single-line electrical diagram prepared by your installer.
  3. The make, model and rated output of the solar modules and the inverter.
  4. The system’s DC and AC capacity ratings.
  5. Proof that the installer is licensed and carries liability insurance.
  6. Any local building or electrical permit numbers.

Step 4: Submit the Interconnection Application

Your installer usually handles the submission, but you should review every page before it goes in. Errors in the equipment ratings or the account number are the most common cause of delays. Once ComEd receives a complete application, it reviews the technical details, may request additional information, and eventually issues approval to interconnect.

Do not energize the system or turn on the inverter for grid parallel operation until you have written approval. Operating early can violate your agreement and may require a costly disconnect and re-inspection.

Step 5: Install the Bidirectional Meter

To track both the energy you consume and the energy you export, the program requires a meter capable of measuring flow in both directions. Depending on your meter type and ComEd’s current practice, the utility may replace your existing meter or install a second device. Schedule the work through the utility’s process and keep the installation confirmation in your records.

Step 6: Understand How Credits Are Calculated

This is where many homeowners get confused. Each billing period, ComEd compares your gross exports and imports. If you exported more than you imported, the surplus generally carries forward as a credit to future bills. The mechanics and the rate applied to the credit have been adjusted over time, so read your current tariff and your bill carefully.

Billing Scenario What Happens What to Check on Your Bill
Exports exceed imports in a month Net surplus carries forward as a credit Look for a carryover kWh balance line
Imports exceed exports in a month You pay for the net kWh you drew Confirm the net billable kWh figure
Annual true-up period ends Remaining credits may be settled or reset under current rules Review the year-end reconciliation statement

Read your bills line by line the first few months. Confirm that the kWh delivered and received match what your inverter reports. A mismatch often points to a meter configuration issue rather than a problem with the program itself.

Why Your Production Data Matters

Keep a record of your inverter’s monthly production numbers. If a ComEd bill shows exports that look far lower than your system should produce, you have an independent figure to bring to the utility. Many inverter apps export monthly totals to a spreadsheet, which makes this comparison simple.

Common Mistakes to Avoid

  • Energizing before approval. Wait for written permission to interconnect.
  • Mismatched equipment data. Make sure the model numbers on the application match the labels on the actual inverter and modules.
  • Ignoring the meter swap. Without the correct meter, your exports may not be recorded at all.
  • Oversizing without checking. A system far larger than your usage can trigger additional review and affect how surplus is handled.
  • Never reading the statements. Credits can be missed or misapplied. Check the carryover balance each month.
  • Assuming rules never change. Compensation structures have been revised. Verify the current tariff before you finalize your financial projections.

Tips for a Smoother Experience

  • Choose an installer familiar with ComEd’s interconnection process and ask how many applications they have submitted in your territory.
  • Keep digital copies of every submission, approval letter and meter-installation confirmation.
  • Set a calendar reminder to review the annual reconciliation statement.
  • If your roof faces a different direction than planned, ask for a revised production estimate before approval.
  • For a deeper look at related structures, compare the approach in other states, such as Net Metering by State: Rules, Credits and What to Check (2026), to understand how Illinois fits into the broader picture.

Understanding Your Credit Options

How much value a system returns depends on whether your array is sized to offset your usage or to exceed it. A system that roughly matches your annual consumption tends to produce the most predictable bill savings, because most of your exports are used against your imports across the year. An oversized array can still be worthwhile, but its benefit depends heavily on the rate applied to surplus credits, so model both scenarios before you commit.

If you are weighing whether net metering is the right fit at all, it helps to understand the broader value proposition. The article What Is the Benefit of Net Metering for Home Solar Owners? walks through the main financial and practical advantages, which you can then test against your own bill history.

Checking Your Interconnection Terms

Read the interconnection agreement before you sign. Look for language about export limits, system size caps, the duration of approval, and what happens if you later add capacity, such as a battery or additional panels. Adding equipment without notifying the utility can void your approval. Ask your installer to explain any clause you do not understand, and keep the signed copy with your other records.

Interconnection rules also address how your system behaves during grid outages. For safety reasons, grid-tied solar systems shut down during outages unless paired with specific backup equipment. This is not a defect. It protects utility line workers, so plan accordingly if you expect to rely on solar during a blackout.

Good monitoring is the easiest way to verify that your credits match your production. These items help you do that:

  • Enphase Envoy gateway reports real-time and historical production from microinverter systems, giving you a reference figure to compare against your ComEd statements. View on Amazon
  • SolarEdge monitoring gateway provides per-module or per-optimizer data for string-inverter systems, which helps isolate shading or underperformance. View on Amazon
  • Emporia Vue energy monitor tracks circuit-level consumption and can help you understand when you draw from the grid versus when your panels cover your load. View on Amazon

FAQ

Is the ComEd net metering program available to all ComEd customers?

Not every customer qualifies automatically. Eligibility depends on your account type, the system’s size and design, and whether the equipment meets interconnection standards. Check with ComEd or your installer before purchasing equipment.

Do I need a new meter?

In most cases, yes. A meter capable of recording energy flowing in both directions is required so the utility can measure exports separately from imports. ComEd schedules the installation as part of the interconnection process.

What happens to excess credits at the end of the year?

Current rules govern how remaining credits are handled during the annual reconciliation. Read the year-end statement carefully and confirm the treatment with ComEd, since terms can change.

Can I add a battery later?

You can often add storage, but you must notify the utility and may need an updated interconnection review. Adding equipment without notice can put your approval at risk.

Will my system work during a power outage?

Standard grid-tied systems shut down during outages for worker safety. Backup power requires a separately designed system with a transfer switch and, typically, storage.

How long does the approval process take?

Timelines vary with application completeness, utility workload and whether additional review is needed. Submit a clean, complete application to avoid back-and-forth requests.

Should I review the program if I move?

Yes. Net metering arrangements are tied to the service location and account. If you sell the home, transfer the interconnection responsibilities to the new owner and notify ComEd promptly.

Do I need a licensed installer?

Licensing requirements apply to electrical and structural work. Confirm your installer’s credentials and insurance. For wiring, roof loading or permit questions, consult a licensed electrician or structural professional.

Conclusion

The ComEd net metering program can turn your rooftop solar output into bill credits, but only if your system is sized sensibly, approved before energizing, and monitored after installation. Start by gathering twelve months of bills, get a clear production estimate, and insist on a complete interconnection application. Review your statements each month so you catch errors early and understand exactly how your credits are applied.

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Claire Whitaker

About Claire Whitaker

Claire Whitaker is part of our editorial team and reviews and edits our home solar guides, checking product details against manufacturer specifications and owner feedback.