Independent · sourced data
Are Illinois's data centers raising your electric bill?
Chicago is the second-largest data-center market in the country — and the electricity bills are beginning to show it. The portion of a typical ComEd bill covering regional grid capacity jumped from under a dollar a month to about eight dollars in a single year. An independent study projects data-center buildout will add $18 billion to ComEd's system costs. This is what's driving your bill up.
What grew in Illinois, 2020 → 2025
$0.91/mo (mid-2024) → ~$8.00/mo (mid-2025) — driven by PJM capacity auction
13.04¢ → 17.69¢ per kWh
IL residential kWh — essentially flat
The capacity charge on your bill jumped 775% in one year. Your rate rose 36%. Your own usage didn't move.
The scale, in real numbers
14 GW
ComEd data-center pipeline
active in ComEd's interconnection queue as of 2025; 28+ GW in total applications received (ComEd regulatory filings)
70% / $9.3B
Share of 2025–26 PJM capacity cost from data centers
of the $14B increase in PJM capacity costs, per PJM Independent Market Monitor
$18 billion NPV
ComEd system cost increase (Synapse study)
projected net present value increase in ComEd costs from data-center buildout, 2025–2040 (Synapse Energy, May 2025)
3% → 13%
Data-center share of Illinois grid load
rising from ~3% of MISO-Illinois load in 2026 to ~13% by 2035 (MISO projection)
What's coming
PJM peak-demand growth by 2030: +32 GW
PJM projects regional peak demand to grow ~32 GW by 2030, ~30 GW from data centers. Northern Illinois (ComEd) is in the PJM footprint (projection).
An independent grid analysis warned of power shortfalls in the ComEd territory starting around 2029 unless significant new generation is added. The Synapse Energy study (May 2025) projects data centers will increase Illinois electricity requirements by 30% by 2040. These are projections — but the pipeline (14 GW in ComEd's queue) makes the direction clear.
The independent finding: $18 billion added to your grid's costs
In May 2025, energy research firm Synapse Energy published a study concluding that data-center load growth in Illinois would add $18 billion in net present value to ComEd's system costs over 2025–2040 — a 30% increase versus a future with no new data centers — translating to roughly an 8.3% increase in average residential bills over that span. The Illinois Commerce Commission responded by approving higher deposit requirements for large data-center projects (requiring more upfront financial commitment). Consumer advocates at the Citizens Utility Board have called for stronger protections, modeled on Ohio's first-in-the-nation data-center tariff.
The 8.3% bill-increase figure is Synapse's 15-year modeled projection, not a utility rate filing. ComEd's supply price increase of ~50% on June 1, 2025 — which drove the ~11% monthly bill jump that summer — is a real filed rate. The two are distinct: the Synapse figure is the long-run trajectory, the June 2025 increase is the immediate hit already on bills.
The line to your PJM capacity charge
Northern Illinois (ComEd) is in PJM, so the regional capacity price spike flows directly into ComEd bills. PJM's market monitor attributed 70% of the record $14 billion PJM capacity cost in 2025–26 to data-center demand — that's $9.3 billion driven by data centers. ComEd's estimated annual capacity-cost impact on consumers: roughly $470 million a year (from our rate-increases tracker).
See the 2025–26 rate increases and the PJM capacity spike →What you can do about your own bill
- Is your bill too high? — compare it to your state's average and see if it's usage or rate.
- Run the free bill audit — check whether a supplier is overcharging you.
- Illinois bill help — assistance and your shutoff protections.
Common questions
- Are data centers raising electricity bills in Illinois?
- Yes, directly. The capacity portion of a typical ComEd bill jumped from $0.91/month (mid-2024) to roughly $8.00/month (mid-2025) — an increase of over 775% — driven by the PJM capacity auction, where data-center demand accounted for 70% of the cost spike. ComEd's overall supply prices rose about 50% on June 1, 2025.
- How big is Chicago's data-center market?
- Chicago is the second-largest data-center market in the U.S. (behind Northern Virginia). ComEd received more than 28 GW in total data-center project applications by 2025, with 14 GW active in its interconnection queue.
- What did the Synapse Energy study find?
- An independent May 2025 study by Synapse Energy projected that data-center load growth in Illinois would add $18 billion (net present value) to ComEd's system costs over 2025–2040 — a 30% increase — and raise average residential bills by approximately 8.3% over that period. That's a modeled projection, not a filed utility rate.
- Did my own electricity use go up?
- No — Illinois residential usage was essentially flat (about +1% from 2020 to 2025) while the average residential rate rose 36%. The demand driving costs up is in the data centers, not your home.
The same story is reshaping bills in other states we cover:
Sources
- Synapse Energy — Illinois data center load growth study (May 2025)
- Citizens Utility Board Illinois — data centers raising bills (Aug 2025)
- Chicago Reporter — how data centers are driving up energy bills
- Block Club Chicago — AI and data centers causing ComEd bills to spike
- Capitol News Illinois — ComEd deposit rules for large-load projects
- Utility Dive — data centers drove 70% of PJM capacity cost spike
Last reviewed June 19, 2026. Verified facts and modeled/forecast projections are distinguished in the text; demand forecasts are projections. General consumer information, not financial advice. RateWatchdog is independent and takes no supplier commissions.