Time-of-Use Pricing for Illinois Commercial Accounts
By Illinois Commercial Energy editorial team
Reviewed by JakenEnergy commercial energy team
Time-of-use and hourly electricity pricing can reward Illinois businesses that use power at the right times — and penalize those that can't shift. It is not inherently cheaper or riskier than a fixed rate; it's a different risk profile that fits some load shapes and not others.
How time-of-use pricing works
Instead of one flat energy price, time-of-use pricing charges more during defined peak periods and less off-peak; hourly pricing goes further, varying by the hour. The logic is simple: use power when it's cheaper and you save; use it when it's expensive and you pay more. The question is whether a facility's load can actually respond.
When it helps — and when it hurts
- Good fit: operations that already run largely off-peak, or that can genuinely shift load (some batch processing, pre-cooling, charging, or off-hours work).
- Poor fit: peak-heavy, inflexible load — daytime-concentrated operations that can't move usage will often pay more than under a fixed rate.
The deciding factor is the facility's hourly load shape, not a general rule.
Interval data is the prerequisite
You cannot evaluate time-of-use suitability from monthly bills. You need interval data to see how much load sits in peak vs. off-peak hours and whether any of it is shiftable. Reconcile the interval data to billed usage first, then model the load against the pricing periods.
Related considerations
Time-of-use overlaps with demand charges and capacity: shifting load off-peak can also reduce peak demand and, in the ComEd/PJM zone, potentially the capacity tag. ComEd's Hourly Pricing FAQ is an official reference for the concepts; program eligibility and suitability must be evaluated separately for the account.
Sources
Time-of-use pricing does not guarantee savings; it is a load-shape decision to evaluate for a specific account.
Frequently Asked Questions
QWhat is time-of-use pricing?
Time-of-use (and hourly) pricing charges different rates depending on when electricity is used — typically higher during peak periods and lower off-peak. It rewards shifting usage away from expensive hours, but it exposes a business to higher costs if its load is concentrated in peak periods and can't move.
QIs time-of-use pricing better than a fixed rate?
Only for the right load. A business that can shift meaningful usage off-peak — or that already runs mostly off-peak — may benefit. A business with peak-heavy, inflexible load can pay more than under a fixed rate. Suitability depends on the facility's actual hourly load shape, which is why interval data is essential before choosing.
QHow do I know if my business is a fit?
Look at interval data. It shows how much load sits in peak vs. off-peak hours and whether any of it is shiftable. Without that hourly picture, a time-of-use decision is a guess. ComEd's Hourly Pricing program materials are a useful reference for the concepts, but suitability must be evaluated for the specific account.