How to Read and Understand Your ComEd Commercial Electric Bill Line by Line

Your ComEd commercial electric bill is a financial document — one that most business owners glance at, flinch at, and file away without fully understanding. That's a mistake. Inside that bill is a roadmap to your energy costs, your efficiency opportunities, and the decisions that will determine how much your business pays for electricity over the next several years.

This guide walks through every major line item on a ComEd commercial electric bill: what it means, what drives it, and — critically — what you can actually do about it. By the end, you'll be able to read your bill with the fluency of a professional energy analyst and identify the specific actions most likely to reduce your total costs.

What Every Line on Your ComEd Commercial Electric Bill Actually Means (And Why It Matters)

ComEd commercial bills vary somewhat by rate schedule (BES, BESH, DS, RDS, TOD, and others), but the fundamental structure is consistent. Here's the anatomy of a typical commercial bill.

Account Information & Billing Summary

The top section of your bill includes:

• Account number: Your unique ComEd account identifier (needed for any supplier switch or data request)
• Meter number: The 10-digit number identifying your physical meter
• Rate schedule: The tariff under which ComEd calculates your charges (e.g., BES for Basic Electric Service)
• Billing period: The start and end dates of the meter reading period
• Read type: "Actual" (meter physically read) vs. "Estimated" (ComEd's estimate when the meter couldn't be accessed) — billing errors from estimated reads are surprisingly common

The Supply Section

For accounts on ComEd's IPA default service:

• Electricity supply charge: Your kWh usage × ComEd's current Price to Compare (PTC). This is the line item you can change by switching to an ARES supplier.
• Purchased Electricity Adjustment (PEA): A pass-through adjustment reflecting ComEd's actual cost of procuring power versus the revenues already built into rates. Can be positive (additional charge) or negative (credit). For more detail, see understanding the ComEd Purchased Electricity Adjustment.

For accounts with an ARES supplier:

• ARES supply charge: Your contracted rate × kWh usage, billed by either the ARES directly or through ComEd's consolidated billing
• The PTC does not apply — your contracted rate replaces it

The Delivery Section

The delivery side of your bill reflects ComEd's regulated charges for physically moving electricity to your meter. These charges are set by the ICC and are the same whether you're on default service or with an ARES.

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Breaking Down ComEd Commercial Rate Charges: Demand, Distribution, and Supply Costs Explained

Understanding the delivery side requires drilling into each component. Here's what you're actually paying for.

Customer Charge (Fixed Monthly Fee)

Almost every ComEd commercial rate includes a fixed monthly customer charge that covers ComEd's administrative costs — meter reading, billing, account management, and infrastructure amortization. This charge appears regardless of how much electricity you use.

Typical range: $10–$50/month for small commercial accounts; higher for larger accounts.

Savings opportunity: None directly — this is a fixed fee. However, it's a factor to consider when evaluating whether your current rate schedule is appropriate for your usage pattern.

Distribution Charge (Variable, Per-kWh)

The distribution charge is the per-kWh cost of delivering electricity through ComEd's local network to your building. It covers:

• Local distribution lines and transformers
• Substations serving your area
• Service equipment at your building
• Long-term infrastructure maintenance and upgrades

How it appears on your bill: An energy charge per kWh × your total kWh consumption for the period.

ComEd's delivery charges have increased steadily as the company pursues ongoing grid modernization investments approved by the ICC. Under ComEd's approved rate cases, distribution charges are projected to continue rising through the decade.

Transmission Charge (Per-kWh or Per-kW)

The transmission charge covers the cost of moving electricity from generators (power plants) across the high-voltage interstate transmission system to ComEd's distribution network. ComEd is in PJM's service territory, and transmission costs are set by PJM and FERC, then passed through to customers.

Key point: PJM transmission costs have been rising due to new infrastructure investment, particularly projects associated with data center load growth and renewable energy integration in the PJM region.

Demand Charge (Per-kW)

For commercial accounts on rate schedules that include demand metering, this is one of the most impactful — and misunderstood — components of your bill.

What it is: The demand charge is based on your peak power draw during the billing period, measured as the highest average power consumption over a 15- or 30-minute interval (depending on your rate schedule). It's measured in kilowatts (kW).

Why it matters: The demand charge reflects the cost of maintaining grid infrastructure capable of delivering your maximum consumption at any moment — even if that peak only occurs once in the billing period. It doesn't matter if your peak was 15 minutes on one Tuesday morning; that's the demand reading for the month.

Example: If your highest 15-minute interval during the month was 85 kW, and ComEd's demand rate is $15.40/kW, your demand charge is: 85 × $15.40 = $1,309 — regardless of how little power you used the rest of the month.

Savings opportunity: Demand charges are a major cost reduction lever. Staggering equipment startup times, implementing demand response strategies, and using battery storage to "shave" demand peaks can meaningfully reduce this line item. See peak shaving 101: reducing capacity tags in ComEd.

Capacity Charge (Your Share of PJM Peak Costs)

The capacity charge is closely related to demand charges but distinct. It's based on your Peak Load Contribution (PLC) — your share of the PJM system's peak demand, measured during the specific "coincident peak" hours in the prior year.

PJM's capacity market ensures the grid has enough committed generating capacity to meet projected peak demand. The cost of this capacity — driven by PJM's annual Base Residual Auction — is allocated among customers based on their PLC tags.

The 2026 reality: The 2026/2027 PJM BRA cleared at $329.17/MW-day — a historic high. This will significantly increase capacity charges for all ComEd commercial customers. A business with a 200 kW PLC pays approximately: 200 kW × $329.17/MW-day × 365 days / 1,000 ≈ $24,028/year in capacity charges alone.

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Hidden Fees and Riders on Your ComEd Business Electric Bill That Could Be Costing You Thousands

Beyond the main supply and delivery components, ComEd bills include several "riders" — ICC-approved surcharges that recover specific program costs. These are often overlooked but can add up to meaningful dollars annually.

Major ComEd Riders for Commercial Accounts

Rider Name	What It Covers	Typical Impact
Energy Efficiency Programs Rider	Funds ComEd's energy efficiency rebate programs (Nicor Gas / ComEd programs under Illinois law)	$0.005–$0.010/kWh
Renewable Portfolio Standard (RPS) Rider	Funds procurement of renewable energy to meet Illinois's RPS requirements	$0.003–$0.008/kWh
Environmental Cost Recovery Rider (ECRR)	Recovers costs of environmental compliance at ComEd's generation assets (legacy)	Variable
Purchased Electricity Adjustment (PEA)	Adjusts for actual vs. projected power purchase costs	Can be + or –
Infrastructure Investment Recovery Rider	Recovers costs of grid modernization investments	Varies by period
Low-Income Assistance Programs	Funds assistance programs for qualifying customers	Small per-kWh charge

Billing Errors: More Common Than You Think

ComEd billing errors occur more often than most business owners realize. Common errors include:

1. Estimated meter reads: If a read is estimated and later corrected with an actual read, you may see a large true-up charge or credit. Persistent estimated reads can distort your demand calculations.

2. Incorrect rate schedule assignment: Businesses that have changed their operations significantly may be on a suboptimal rate schedule for their current usage pattern.

3. ARES rate mismatches: For businesses with a competitive supplier, verify that the rate on your bill matches your contract. Suppliers occasionally apply the wrong rate, and the discrepancy may not be caught without an active bill audit.

4. Incorrect PLC assignment: If ComEd assigns a higher PLC to your account than your actual coincident peak usage warrants, your capacity charges are inflated. This is correctable by requesting a PLC review.

5. Duplicate charges: In rare cases, both ComEd and an ARES supplier bill for supply in the same month. This requires prompt dispute resolution.

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How to Use Your ComEd Commercial Bill Analysis to Immediately Lower Your Business Energy Costs

Understanding your bill is only step one. Here's how to turn that knowledge into action.

Action 1: Benchmark Your Supply Rate

Pull your last 12 bills and calculate your effective supply rate per kWh. Compare it to:

• ComEd's current Price to Compare (if on default service)
• Your contracted ARES rate (if already with a supplier)
• Current competitive market quotes

If you're paying more than what's available through a competitive ARES, a supplier switch is your highest-leverage action. See our guide on how to switch energy suppliers in Illinois.

Action 2: Analyze Your Demand Profile

Request 15-minute interval data from ComEd (or download via Green Button). Identify your highest demand peaks and look for patterns:

• Are peaks concentrated in a specific time of day or day of week?
• Could they be reduced by staggering equipment startup?
• Are they seasonal (summer HVAC loads)?

Even a 10–15% reduction in peak demand on a $15/kW demand rate translates to meaningful monthly savings.

Action 3: Review Rider Applicability

While most riders can't be avoided, verify that you're on the most appropriate rate schedule for your business. Businesses with specific operational characteristics (e.g., primarily off-peak usage, high load factor) may qualify for rate schedules with lower applicable riders or demand structures.

Action 4: Request a PLC Review

If your capacity charges seem high, ask your broker or energy advisor to verify your PLC assignment against your actual coincident peak usage. If there's an error, filing a correction with ComEd can reduce your annual capacity charges prospectively.

Action 5: Audit the Last 24 Months

Have an energy professional review your bills for the past 24 months looking for:

• Estimated reads that were later reconciled incorrectly
• Rate schedule changes you didn't request
• ARES rate discrepancies vs. your contract
• Unusual spikes in any single charge category

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Conclusion: Your Bill Is More Than a Payment Request — It's a Strategy Document

A ComEd commercial electric bill is a window into your business's energy economics. Every line item tells you something: about how you use power, about the cost structure of the grid, about the opportunities available to reduce what you pay.

The businesses that manage energy costs most effectively don't just pay their bills — they analyze them. They know their demand readings, their capacity tags, their supply rates, and their rider costs. And they use that knowledge to make decisions: when to switch suppliers, when to implement efficiency measures, when to engage demand response, and when to push back on billing errors.

You don't need to be an energy engineer to do this. You need the right framework and, ideally, the right partner. illinoiscommercialenergy.com offers free commercial bill analysis for Illinois businesses. Bring us your last 12 ComEd bills and we'll walk you through every line item, identify your savings opportunities, and give you a clear action plan — at no cost and no obligation.

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Sources:

• ComEd – Tariff for Electric Service (Rate Schedules BES, BESH, DS)
• Illinois Commerce Commission – ComEd Rate Case Approvals
• PJM Interconnection – Capacity Market and PLC Explanation
• U.S. Energy Information Administration – Retail Electricity Prices by Sector
• ComEd – Purchased Electricity Adjustment Information

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