On a ComEd commercial account, the demand charge does not appear on the bill under that name. It appears as the Distribution Facilities Charge, on the delivery side of the bill. It follows the general demand-charge mechanism, but ComEd applies a specific set of rules that decide exactly which moment of the month sets it.
It is billed on demand, not on energy
The Distribution Facilities Charge is not billing the energy you used over the month. It is billing the highest rate at which you drew power, your peak demand, measured in kilowatts over a thirty minute interval. A site can use a modest amount of total energy and still carry a large Distribution Facilities Charge, because the two numbers measure different things.
Why is the ComEd delivery charge so high?
Because on a business account it is not priced on how much electricity you used. It is priced on your single worst thirty minute interval, and that price barely falls as your business grows.
In the 2026 filed schedule, at Secondary voltage, the base rate runs $12.78 per kW for Medium Load, $12.47 for Large Load, $11.49 for Very Large Load, and $11.63 for Extra Large Load. A site four times the size of another pays roughly the same rate for every kilowatt of peak. The charge scales with the shape of your demand, not the size of your bill, which is why it can feel disproportionate to a month where you did not use much.
Three properties compound that. It is set only inside the nine to six weekday window, so the moment that decides it is a working-hours moment. It is a flat rate, so there is no volume discount to grow into. And because there is no ratchet on the standard commercial classes, the number resets every month, which cuts both ways: one bad afternoon does not follow you into next year, but nothing you did last month helps you this month either.
A residential ComEd bill works differently, and this is where the name causes trouble. The same Distribution Facilities Charge appears on residential accounts billed on volume, not demand. On one residential bill we reconciled, it read 3,048 kWh x 0.06333 = $193.03 and was the largest single delivery line on the bill. That is one bill in one billing period, not a published residential rate. We have reconciled ComEd's commercial schedule against real bills and we have not done the same for the residential schedule, so we are not going to quote you a residential rate we cannot stand behind.
So if the line on your bill is a dollar figure per kilowatt, the rest of this page applies to you. If it is cents multiplied by kilowatt hours, you are looking at the volumetric version, and your lever is total consumption rather than peak timing.
If you are not sure which one you are holding, the free ComEd bill reader reads the PDF and tells you. It reports the charge as your bill states it, and on a commercial bill it works out the delivery class by reconciling the demand line against the filed ratebook rather than asking you to know it.
How is the ComEd demand charge calculated?
First, ComEd measures billed demand as the highest thirty minute demand recorded inside the on-peak window: nine in the morning to six in the evening, Monday through Friday, excluding holidays. Power drawn outside that window does not set the charge, no matter how high it climbs. A spike at eight thirty in the morning, thirty minutes before the window opens, can be the highest reading of the day and still set nothing.
Second, the charge is a flat rate per kilowatt of that billed demand. There is no separate off-peak demand charge, and on the standard commercial delivery classes there is no ratchet carrying a past peak forward. One qualifying interval, priced once, for the month. That second property is worth more than it sounds, because it decides whether a single bad afternoon costs you one month or twelve, and therefore what preventing it is worth.
What the rate has looked like
Two numbers set this charge, and a ComEd bill only shows you one of them.
The filed base rate
The base Distribution Facilities Charge is a flat dollar amount per kilowatt, set by delivery class and revised on ComEd's filed schedule. These are the base rates as filed with the Illinois Commerce Commission (Rider RDS, Docket 24-0378):
| Delivery class | 2025 base ($/kW) | 2026 base ($/kW) | Basis |
|---|---|---|---|
| Small Load (under 100 kW) | 12.71 | 12.50 | Reconciled to real bills |
| Medium Load (100 to 400 kW) | 13.02 | 12.78 | 2025 reconciled; 2026 tariff-filed |
| Large Load | 12.72 | 12.47 | Tariff-filed |
| Very Large Load | 11.77 | 11.49 | Tariff-filed |
| Extra Large Load | 11.43 | 11.63 | Tariff-filed |
"Reconciled to real bills" means we have matched that base rate against an actual ComEd bill, to the cent. "Tariff-filed" means the rate is read straight from ComEd's filed informational sheet, but we have not yet reconciled a bill in that class. ComEd revises these rates on its own schedule, so the values shown are the rate in effect for the periods we reconciled (2025) and the current filed rate (2026).
The rate you actually pay
The base rate is not the rate on your bill. ComEd layers delivery-service adjustment riders on top of it, so the effective per kilowatt charge runs higher. On the accounts we reconciled, the measured demand matched the billed demand exactly and the charge matched within ComEd's own rounding:
- A Small Load account on a 2025 bill paid about $14.59 per kW all in, on a $12.71 base. A 40.91 kW peak produced a $596.88 Distribution Facilities Charge.
- A Medium Load account on a 2025 bill paid about $14.92 per kW. A 242.57 kW peak produced a $3,619.14 charge.
- A Small Load account on a 2026 bill paid about $12.93 per kW under the restructured bill format. A 46.20 kW peak produced a $597.37 charge.
The gap between the filed base and the rate you pay is not an error. It is the delivery-service riders doing their work, quietly, on a line the bill never itemizes for you. The rate itself is rarely the surprise. The surprise is that a single interval, often half an hour long, sets a line that can rival the entire energy cost for the month, and the bill shows only the result, never the interval that produced it.
On 2026 bills the riders are no longer quiet. The rate case that set these rates also restructured how they are printed, so what used to be one delivery line is now several. That is why a 2026 bill can look more expensive than a 2025 one at the same effective rate.
Find the interval that set yours
The bill gives you the Distribution Facilities Charge as a finished number. The interval data behind it holds the thirty minutes that actually set it. You can reconstruct that on your own ComEd bill, reconciled to the cent, with the free demand charge tool. We do not sell energy and we take no commission. The tool exists to make the charge legible, nothing more.
To see it already done, we reconciled six real ComEd commercial bills to the meter, and refused to reconcile a seventh whose data did not match.
The Distribution Facilities Charge is the largest delivery line on most bills, but it is not the only one. Every other line on a ComEd bill covers the rider and adjustment block underneath it, each one reconciled against the filed tariff, including which two of them can actually be avoided.
If you are deciding whether to act on that charge, a battery for peak shaving being the common case in Illinois now, the measured feasibility read reconstructs your demand structure and tests whether the investment pays against your real peaks, from your own data rather than a projection.