Do data centers raise electric bills? What it means for EV charging in Chicago

Last updated: October 11, 2026

Data centers are genuinely pushing electricity bills higher across ComEd territory. The mechanism is the PJM capacity auction — the wholesale market where ComEd's grid operator buys promised future generating capacity. Those auction prices went from $28.92 per megawatt-day a few cycles ago to the federally approved cap of $333.44 per megawatt-day for 2027/2028, and PJM's own market monitor attributes most of that increase to data-center demand.

But here's the part that matters for EV owners: ComEd's "price to compare" — the benchmark supply rate — is 10.103 cents per kWh from October 2026 through May 2027, about 53% higher than two years ago, per the Citizens Utility Board. Even at these elevated prices, a typical Chicago driver pays roughly $25–$48 a month to charge at home — far less than gasoline for the same miles. The data-center effect is real, but it's measured in cents per kWh, and overnight charging largely offsets it.

Your ComEd bill has two big pieces: supply (the electricity itself) and delivery (the wires). The data-center effect lives in the supply piece. PJM Interconnection runs the grid for more than 67 million people across 13 states and Washington, D.C., and each year it holds a capacity auction — paying power plants to promise they'll be ready a few years out. When data centers started requesting enormous blocks of future power, PJM had to buy far more capacity than before:

PJM's independent market monitor, Monitoring Analytics, estimated that data centers were responsible for about 63% of the 2025/2026 price increase — roughly $9.3 billion in added cost recovered from customers. In the December 2025 auction, about $6.2 billion of the data-center share was for facilities not yet built — forecasted load that may or may not materialize, but which ratepayers cover regardless.

One advocacy projection (from the Natural Resources Defense Council) suggests average PJM household bills could run roughly $70 a month higher by 2028 than before the surge if the trajectory holds. Treat that as a projection, not a bill you'll see next month — but it shows the direction.

ComEd's position is that large-load customers should pay their own way. In January 2026, it signed Transmission Security Agreements with eight large-load customers, locking in commitments for more than 6.5 gigawatts of forecasted new load. The take-or-pay structure obligates those customers to pay for up to ten years of transmission service — ComEd says the agreements prevent more than $2 billion in transmission charges from being passed to existing customers over the next decade.

The honest caveat: those agreements cover transmission costs for new large loads. The wholesale capacity costs described above are a separate charge, set by PJM's auctions — and those are already baked into your supply price. One more cushion: Illinois' Carbon Free Energy Resource Adjustment flips into a credit when energy prices run high (recently about 0.115 to 1.6 cents per kWh off the supply charge), though that benefit is scheduled to end in June 2027.

If you're in Naperville, check whose name is on your bill before applying any of this. Most of Naperville isn't served by ComEd at all — the City of Naperville runs its own municipal electric utility, in business for over 120 years and serving 60,000+ customers, buying wholesale power through the Illinois Municipal Electric Agency. A few outlying addresses with Naperville mailing addresses do fall in ComEd territory.

Why it matters for EV charging: wholesale capacity pressure still flows through to a municipal utility buying power in regional markets, but your rates are set by the city — not by state regulators — and ComEd's customer programs described below apply to ComEd customers specifically. See our Naperville installation guide for the local details.

Here's the math for a typical Chicago-area driver covering about 12,000 miles a year. A typical EV uses roughly 0.30 kWh per mile, so that's about 300 kWh per month of charging.

Your all-in variable rate on ComEd's standard plan is roughly 16 cents per kWh — that's the 10.103¢/kWh price to compare (supply plus transmission) plus about 5.9¢/kWh in delivery charges ComEd expects for 2026. So:

For perspective, that's the energy cost of running a space heater a few hours a day — except it replaces your entire gasoline bill. Even with supply prices 53% higher than two years ago, home charging remains far cheaper per mile than gas. The data-center story is worth knowing; it's not a reason to skip the charger.

Level 1 vs. Level 2 on your bill: the charger type barely changes the cost — you pay per kWh either way. What changes is speed and practicality. A standard 120V outlet (Level 1) draws about 1.4 kW and adds roughly 4–5 miles of range per hour. A 40-amp Level 2 unit draws about 9.6 kW and adds roughly 30 miles per hour — a typical 60 kWh battery fills in about six and a half hours overnight. Level 2 is also slightly more efficient, wasting less energy as heat. Our Chicago installation cost guide covers what the hardware and electrical work run.

• Try ComEd Hourly Pricing. You pay the real hourly wholesale price instead of a flat rate — and overnight hours, when you'd charge, are the cheapest. ComEd reported 70,000+ residential customers enrolled as of September 2026, with over $63 million in supply savings since 2007. More than 80% of participants paid less than the standard rate in 2025, saving an average of $166 a year.
• Look at Time-of-Day Pricing. Launched in July 2026, it varies both supply and delivery charges by time of day. Enrolled EV owners also earn $2 per vehicle per month in bill credits for up to 24 months (two vehicles max).
• Schedule your charging. Nearly every Level 2 smart charger lets you set charging windows. Overnight charging on either program above is the single biggest lever on your EV fuel cost.
• Get a free home energy assessment. ComEd's Energy Efficiency Program sends an advisor — in person or virtual — and installs free or discounted gear (LEDs, smart thermostats). Lower household usage means more headroom for the charger. Schedule at ComEd.com/Assessment or call 855-433-2700.