Commercial battery storage in Illinois, with a rebate that only pays if you pair it.
Northern Illinois has a strong case for behind-the-meter storage: ComEd's distributed-generation rebate pays $250 per kWh of storage, capacity prices have cleared at the cap, and the transmission tag is worth real money on a competitive supply contract. The catch that trips most proposals is that the rebate requires the battery to be paired with a renewable generator. Standalone storage gets none of it. KEEL prices both cases and shows the owner the difference.
Utilities KEEL prices in Illinois
KEEL's Illinois tariff work is in Commonwealth Edison territory, which covers Chicago and northern Illinois. Ameren Illinois accounts downstate are screened from the bill on request.
| Utility | Rate classes | Demand charge as read | What it means for a battery |
|---|---|---|---|
| ComEd | Large Load, secondary / primary | $12.91 / $10.16 per kW-month (April 2026) | Billing demand is the highest 30-minute demand between 9 am and 6 pm on weekdays. A battery has to cut the peak inside that window; an overnight or weekend peak does not count. |
| ComEd | Very Large Load, secondary / primary | $12.42 / $10.10 per kW-month (April 2026) | Same window. Delivery rates have fallen 8 to 12% since early 2025, and the two classes are diverging in the 2027 filing, so KEEL prices off the current sheet, not last year's. |
Rates as read from the filed tariffs in August 2026. Utilities re-file often; KEEL re-reads the effective sheet on the day a project is priced.
What a battery earns in Illinois
ComEd DG rebate: $250 per kWh, paired only
Open, uncapped and payable to the owner or operator of the system, which means a lease can claim it. The battery must be associated with a distributed renewable generator at the site. On a 2 MWh system that is $500,000 the standalone version does not get.
PJM capacity and transmission tags
Capacity cleared at the cap for 2027/28 and again for 2028/29; ComEd's network transmission charge is about $47 per kW-year on the account's transmission tag. Discharging in the handful of peak hours that set the tags lowers next year's charges, if the supply contract passes them through.
Demand charges in a nine-hour window
ComEd bills the highest 30-minute demand between 9 am and 6 pm on weekdays, so the battery is dispatched to that window rather than to an overnight or weekend peak.
State and utility programs
Illinois has one large storage rebate and it comes with a pairing condition. The rest of the stack is federal and PJM.
| Program | What it pays | Who can claim it | Notes |
|---|---|---|---|
| Federal investment tax credit (§48E) | 30%+ of eligible cost: a 30% base (prevailing-wage rules apply at 1 MW and above) plus a 10-point adder for domestic content | The owner of the equipment; nonprofits and public bodies by direct pay | See the federal guide. |
| ComEd Rider DG Rebate, energy storage | $250 per kWh of storage capacity | Storage associated with a distributed renewable generating facility at the site; available to the owner or operator, so a lease can claim it | Standalone storage with no paired renewable does not qualify. One rebate per unit of capacity; KEEL documents which party claims it in the lease. |
| ComEd Rider SPWS Rebate | Rebates the interconnection and telemetry cost of participating in PJM frequency regulation | The retail customer | New in 2026 and has no pairing condition, but it pays the customer rather than the system owner and is upside, not an underwriting line. |
| Illinois Shines / Adjustable Block Program | Renewable energy credits for solar; no storage payment | Solar projects | Storage appears only as an array-sizing allowance. Not a storage incentive. |
| PJM capacity and transmission tag management | Avoided capacity and network-transmission charges on the account's tags | Accounts on competitive supply with pass-through, or on default service billed on their own tag | On a fixed all-in supply contract the supplier keeps the saving. KEEL checks the supply contract before booking it. |
| ComEd demand response (Rider VLR) | No published rate | — | Compensation is set by ComEd case by case. KEEL values it at zero. |
Read from program documents and filed tariffs in August 2026. Programs open, fill and change; KEEL confirms each line against the live source before it goes in a proposal. The federal credit applies in every state on top of what is listed here, subject to the conditions in that guide.
What to watch in Illinois
- The DG rebate's pairing requirement is the single most common mispricing in Illinois storage proposals. If a proposal shows $250 per kWh on a standalone battery, the number is wrong.
- ComEd's billing demand is a nine-hour weekday window, not the 24/7 monthly maximum. A battery sized to a whole-month peak is solving the wrong problem.
- PJM capacity has cleared at the cap; PJM's own uncapped simulation for ComEd runs far higher. KEEL prices at the cleared price and treats anything above it as sensitivity, not base case.
- Illinois' combined corporate rate is 9.5%, which makes accelerated depreciation worth more to a taxable owner here than in most states.
How KEEL prices an Illinois project: establish first whether solar is on the site or in scope, because that decides whether the $250 per kWh rebate exists. It then models the 9 am–6 pm weekday peak against the current delivery sheet, adds tag management only where the supply contract shows pass-through, and values ComEd demand response at zero. Where solar is not in scope, the owner sees the standalone case and the paired case side by side.
What to send
Twelve months of electric bills for the meter you have in mind (interval data if you have it), the service address and the rate class printed on the bill. That is enough for a first read on demand charges, program eligibility and a monthly payment range. See Lease vs. Buy for how the numbers land under each structure, or schedule a property review.
Common questions
Does ComEd pay a rebate for commercial battery storage?
Yes, $250 per kWh under the distributed-generation rebate rider, for storage associated with a renewable generator at the site. It is open and uncapped as of August 2026 and can be claimed by the owner or operator of the system. Standalone storage with no paired renewable does not qualify.
Can a leased battery claim the ComEd rebate?
Yes. The rider makes the rebate available to the owner or operator of the eligible facility, so it can be claimed under a lease. KEEL writes into the lease which party claims it.
What does standalone storage earn in Illinois?
The federal credit, demand-charge savings inside ComEd's 9 am–6 pm weekday billing window, and PJM tag management where the supply contract passes those charges through. No state or utility rebate applies to standalone storage.
Have a Illinois building in mind?
Send the address and a bill. KEEL returns the demand-charge read, the program lines the site qualifies for and a monthly payment range, with the source for each.