Back in the spring, energy officials predicted that Illinoisians would pay about 10% to 15%, or an average of $10.60 more, on their utility bills this summer.

Since then, at least two major heat waves swept across the Midwest in June and July, bringing temperatures above 90 and heat indices of more than 100. But hot temperatures aren’t the only reason some have seen higher-than-normal energy bills recently.

Another major component is the increase in demand for electricity on the grid that the region uses, energy economist Kenneth Gillingham of Yale University said.

“There’s two things that could be going on. One is we’ve had very hot weather; it’s been another hot summer,” Gillingham said. “And rates have been largely inching up. ... There has been, broadly around the country, an upward pressure on rates.”

So many Illinoisans have sought financial assistance to help pay their energy bills since June that ComEd closed its new customer assistance program only weeks after it opened, a company spokesperson confirmed.

Spiking energy rates also have been at the center of many lawmaker debates this year, a constituent issue not likely to go away, said state Sen. Sue Rezin, R-Morris. Democratic Gov. JB Pritzker has argued that energy grid reform is needed. But other Illinois Republicans argued in a virtual conference earlier this month that restrictions on coal-powered plant builds needed to be lifted, despite pushback from climate experts that coal plants release harmful greenhouse gases.

“To me, it shows how much rate payers are currently struggling to afford these recent rate increases,” Rezin said. “It’s critical that Illinois families have access to timely financial relief, especially as high energy bills continue to place a strain on household budgets.”

ComEd spokesperson Tom Dominguez said the Customer Relief Fund started in June was meant to be a temporary “bridge” to help customers get through the summer before a new bill assistance program opens in January.

“ComEd knows that, for many families, every dollar matters – and a higher electric bill can be stressful, especially in the summer when kids are home and air conditioning is essential," Dominguez said.

The $10 million relief fund, supported by ComEd’s parent company, Exelon, offered one-time grants of up to $500 for eligible residential customers, and up to $1,000 to eligible nonprofits with past-due bills, he said.

“Due to significant demand, with approximately 77,000 applications received within the first three weeks, ComEd closed the fund to all new applications,” Dominguez said.

As of Aug. 14, ComEd had approved $5.5 million in grants for about 15,000 residential and nonprofit customers. Applications still are being processed, and additional qualifying customers should receive notification and credits to their bills within the next one to two billing cycles, he said.

Natural gas utility Nicor, which serves 2.3 million customers in Illinois, likely accounts for the smallest portion of a home’s bills right now, Nicor spokeswoman Jennifer Golz said. Nicor customers’ average bill in August so far is $37, compared with $33.21 in August 2024, she said.

“We are able to buy gas in the summer when it’s historically cheaper, store it, and then take it out during the winter when demand is higher,” Golz said.

How does the energy grid impact my bill?

The ComEd spokesman also pointed to the PJM Interconnection – the mid-Atlantic grid operator in charge of overseeing energy distribution for millions – as a major contributing factor to the spike in people’s bills.

Gillingham agreed.

How does electricity get from a generator to someone’s home?

Illinois has many different types of energy generators: wind turbines, solar farms, natural gas, coal and nuclear power plants. They generate energy and feed that energy into high-voltage transmission lines, which travel to substations where voltage is stepped down. The energy then makes its way to retail consumers. Consumers control how much energy they use and pay at a rate based on signals sent to them from this region’s independent systems operator, PJM.

The PJM grid covers 13 states, including Washington, D.C., Chicago and northern Illinois. PJM sets rates based on energy trends used to predict how much energy the grid can handle each day, Gillingham said.

“The price at any given time is set where the supply equals the demand,” Gillingham said.

But PJM doesn’t set local electricity bills, PJM spokesman Jeff Shields said. That’s on the utility companies and regulators. The energy market operates like a stock exchange, according to PJM.

“What we do is run the power grid and the wholesale markets that make sure electricity is there when people need it,” Shields said.

Prices are set to ensure all generators on a grid – from the cheapest energy conductors such as nuclear plants to the most expensive: often aged, coal-powered, energy-sucking, local air-polluting backup generators – have enough power to run, Gillingham said.

And PJM doesn’t just set the rates based on energy consumption. It also has a market for capacity during peak times, Gillingham said – for example, a heat wave at 6 p.m. when everyone’s home from work, blasting air conditioning and running appliances.

“During these peak times ... [PJM needs] to make sure there’s enough capacity to go around,” Gillingham said.

PJM will make payments to ensure every power plant on the grid remains operational in anticipation of people’s peak energy consumption.

“But who ends up paying? Retail customers,” Gilingham said. “PJM’s like, ‘We have these costs, these are the costs to keep the grid going. Somebody’s got to pay for it.’”

The catalyst for the current spike is partly a product of a record price hike from a PJM electricity “capacity auction” that took effect June 1, according to the Illinois energy watchdog group Citizens Utility Board.

“In the last auction, covering the 12-month period from June 2025 through May 2026, prices for most of PJM jumped about 830%, from $28.92 per megawatt-day in last year’s auction to a record $269.92 per megawatt-day,” according to a CUB report in May.

Shields said PJM’s prices rose in the latest auction because electricity demand is outpacing how quickly new power plants are built, primarily due to data center development.

The PJM spokesman said auction costs are a fraction of a household’s electric bill.

“We’re working with states and the industry to bring new power online faster and, in some cases, to keep existing plants running so that electricity supply keeps up with electricity demand, which will work to control costs while keeping the grid reliable,” he said.

Are data centers a factor?

Americans are using more electricity than they ever have: buying electric cars, putting in heat pumps, running appliances and operating major facilities on electricity.

“Electricity demand is starting to really rise again,” Gillingham said. “And data centers are probably the dominant reason.”

Data centers are costly to power, he said. They take energy to run and large amounts of water to keep enormous servers cool enough to operate continuously.

The actual effect of data centers on electricity bills is difficult to pin down, The Associated Press reported. In the past two decades, data centers have multiplied due to increased demand for cloud computing, information storage and data processing, Capitol News Illinois reported. However, data centers now also serve artificial intelligence and cryptocurrency (digital money) mining.

Northern Illinois, particularly around the Chicago suburbs, is home to more than 200 data centers, CNI reported. Tech companies and lawmakers tout the builds as significant investments in local communities, bringing property tax incentives and jobs.

A 158-acre AI data center has been proposed in Morris off Route 6.

In DeKalb, Meta – the parent company of Facebook, Instagram, WhatsApp and others – has invested more than $1 billion to install a multi-building, 2.3-million-square-foot data center facility.

At least eight data center developments have been proposed or approved to date in nearby Yorkville, although some proposals have yet to be finalized. The latest, a $100 million 1,037-acre data center known only as “Project Cardinal,” right now is in the works, but the tech company behind it hasn’t been announced. Tax revenue from the project was drastically overestimated, however, city officials said recently. Project Cardinal could be built next to a 540-acre development data center, just north of a 230-acre CyrusOne data center.

Gillingham said data centers are being built these days primarily to service AI models. Digital technology grows in use every day across industries.

A single Google ChatGPT query might mean an AI model scraping the web to process “an enormous amount of data,” Gillingham said. And that processing takes energy.

A Meta spokesperson told Shaw Local News Network that the company focuses on constructing data centers that use renewable energy. That also can look like cooling the servers with liquid, something Google also does.

“We work closely with our project partners, including developers and utilities, to add new clean and renewable energy projects to local grids,” the Meta spokesperson said. “In Illinois, five Meta-supported projects are adding 765 megawatts of new renewable energy to the grid.”

Meta also covers the costs local utilities incur to run the data centers, the spokesperson said.

Rezin called data center growth in Illinois “a key factor in rising energy demand,” but also said “they bring significant economic benefits.”

In DeKalb, for example, Meta’s data center reuses water multiple times before discharging it as wastewater and collects rainwater on-site. Meta also publishes an annual sustainability report on energy use.

What relief is out there?

Much of the energy conversation about who pays how much for what has turned to policy: Some lawmakers are pushing energy corporations to better manage cost burdens for consumers.

On July 16, Pritzker joined eight other governors to issue a bipartisan open letter to PJM’s board of managers asking the grid operator to better “meet the challenges” facing energy consumers.

“Today, as our regional grid confronts intertwined reliability and affordability crises, PJM itself faces an unprecedented crisis of confidence from market participants, consumers and the states,” the letter reads. “In the past, other regions looked to join PJM due to its many strengths; today, across the region, discussions of leaving PJM are becoming increasingly common.”

In a July 18 response letter, PJM board Chair David Mills said PJM’s “operators are keeping the lights on through some of the most challenging circumstances that any grid operator anywhere has faced in its history” for the 67 million people who use the grid.

“PJM has also entered into a collaboration with Google to consider how artificial intelligence can be deployed to further speed up generator interconnections,” Mills wrote.

In January, ComEd intends to launch what the company is calling its low-income discount program, Dominguez said.

“This program will enable qualifying income-eligible customers to receive a percentage-based discount on their monthly electric bill, determined by income level,” Dominguez said.

Other relief programs remain open for ComEd customers to help pay their electric bills.

The Low-Income Home Energy Assistance Program is meant to provide a one-time grant with no payback required to income-qualifying residents outside Cook County. Customers can make payment arrangements of up to 12 months for past-due balances; can sign up for budget billing; can ask to have late-payment charges waived; can sign up for high-usage alerts to help mitigate energy use in real time; can or sign up for other ComEd programs such as Catch Up and Save to eliminate past-due balances or Supplemental Arrearage Program based on income and on-time payment history.

And while nuclear generators aren’t cheap to build, they’re typically the cheapest to run, Gillingham said. More of that type of energy could mitigate utility costs to the consumer, Rezin said.

“Illinois residents are facing higher energy bills due to a combination of factors, including increased demand and less supply,” Rezin said. To address these issues, I believe we need a more reliable and diversified energy mix and the utilization of our state’s expertise in nuclear energy.”

Electricity rates are expected to taper by October, CNI reported.