Quick answer
EnergySage puts the average installed cost of home battery storage in Illinois at about $1,283 per kWh. For one 13.5 kWh battery, that's roughly $17,300 before incentives, or about $13,250 after the ComEd or Ameren storage rebate of about $300 per kWh.
What does a home battery cost after the Illinois rebate?
| Battery capacity | Before rebate | Storage rebate | After rebate |
|---|---|---|---|
| 10 kWh | $12,800 | $3,000 | $9,800 |
| 13.5 kWh | $17,300 | $4,050 | $13,250 |
| 20 kWh | $25,700 | $6,000 | $19,700 |
| 27 kWh | $34,600 | $8,100 | $26,500 |
These are averages. EnergySage's Illinois data puts a 13 kWh system at about $14,200 to $19,200 before incentives, depending on the brand, installer and home. Adding a battery at the same time as solar usually costs less than adding it later, because the installer does the electrical work once.
Why do battery prices vary so much?
- Brand and model. EnergySage's national data puts Tesla Powerwall 3 at about $998 per kWh, below the roughly $1,159 national average for home batteries.
- Backup setup. Whole-home backup with a gateway or new panel costs more than backing up a few essential circuits.
- Electrical upgrades. An older or full main panel may need work before a battery can be added.
- Installer. Prices for the same battery can differ by thousands between companies, so compare at least two or three quotes.
Can a battery lower my electric bill in Illinois?
It can, mostly by shifting when you use power. Solar systems connected since 2025 earn only the supply rate for exported power, so storing midday solar for the evening is worth more than exporting it. On ComEd's Time-of-Day rate, summer peak supply from 1 to 7 p.m. costs about 16.6 cents per kWh, compared with about 2.8 cents overnight, before delivery charges, according to the Citizens Utility Board.
Savings depend on your rate plan and habits, so ask installers to model your bill with and without the battery. See solar with hourly pricing.
Is there a federal tax credit for home batteries?
Not for homeowners who buy. The federal residential credit ended for batteries installed after December 31, 2025, the same as for solar. Leased batteries are different: the company that owns them may still claim a business credit. See the federal solar tax credit in 2026.
What should a battery quote include?
- 1
Battery model and capacity
The usable kWh and how many units.
- 2
What gets backed up
Whole home or a list of essential circuits.
- 3
Price with and without the rebate
The storage rebate should be shown separately.
- 4
Electrical work
Any panel upgrade, gateway or backup panel, itemized.
Then check the solar side of the quote with our quote checker.
Sources
- EnergySage: Energy storage cost data, Illinois
- EnergySage: How much do home batteries cost?
- Berkeley Lab: U.S. distributed solar and storage, 2025 data update
- Citizens Utility Board: ComEd's Time-of-Day pricing program (August 2026)
- IRS: FAQs on changes to Sections 25C, 25D and other credits under the 2025 law (Public Law 119-21)
- ComEd: Distributed generation and storage rebates
- Illinois Public Utilities Act, 220 ILCS 5/16-107.6: Distributed generation and storage rebates
This guide is general information, not tax, legal or financial advice. Incentive programs change, so confirm current terms with your installer, your utility and a tax professional.