ComEd Summer 2026 Supply Price 10.399¢/kWh

What ComEd filed for summer 2026

On May 15, 2026, ComEd filed a tariff setting its summer supply rate at 10.399 cents per kilowatt-hour for June through September [cub-comed-summer-2026]. That figure covers the cost of the electricity itself plus a transmission charge. It does not include ComEd's delivery charges, demand charges, taxes, or riders.

The Citizens Utility Board noted this summer price is about 50 percent higher than two years ago [cub-comed-summer-2026]. ComEd does not profit from supply; state law requires the utility to pass supply and transmission costs through with no markup [cub-comed-summer-2026]. The winners in a capacity-driven spike are generators selling into PJM, not the wires company.

For a cannabis operator, the supply line is only part of the story. Indoor cultivation loads are heavy, flat, and peaky. Lighting alone averaged 66 percent of electricity use in a survey of licensed producers in Oregon and Washington [nwpcc-cannabis]. When supply rises 50 percent in two years, energy charges move fast even if your kWh profile stays the same.

Why capacity is showing up in your supply rate

CUB's May 2026 alert ties the spike to reserve power, called capacity, in PJM [cub-comed-summer-2026]. You pay for electricity you use today and for the commitment that enough power will exist on the hottest afternoon three years from now. PJM's interconnection queue backlog slows new solar, wind, and battery projects from entering the market [cub-comed-summer-2026].

Data-center load growth also feeds capacity forecasts. CUB urged the Illinois General Assembly to pass the POWER Act, which would require large data centers to bring their own clean power for firm service [cub-comed-summer-2026]. That debate matters to growers because everyone in the same zone shares capacity costs until policy or new generation changes the forecast.

If you switched to a retail supplier last year, your contract may pass PJM capacity through as a separate line or embed it in the all-in price. Read fixed vs index vs block-and-index contracts before assuming a "fixed" quote covers every ISO charge.

How the summer rate hits a Chicago-area grow (worked example)

Every number below is an input we chose so you can follow the math. Swap in your facility's actual kWh and rate class.

Input	Value	Notes
Monthly kWh	180,000	Assume a mid-size indoor facility
ComEd summer supply	10.399¢/kWh	Filed rate [cub-comed-summer-2026]
CFERA credit (June)	−1.3¢/kWh	CUB estimate [cub-comed-summer-2026]
Net supply for June	9.099¢/kWh	10.399 minus 1.3
Delivery energy + demand	Not in supply rate	Tariff-specific

Supply-only math for one summer month:

• At filed rate: 180,000 kWh × $0.10399 = $18,718
• With June CFERA credit: 180,000 × $0.09099 = $16,378
• Difference from credit alone: $2,340 for that month

CUB said ComEd customers could pay an average of 12 percent more on monthly bills overall, but hotter weather pushes usage and bills higher [cub-comed-summer-2026]. A grow running full HVAC and dehumidification in July will exceed that average quickly.

Delivery demand charges do not change when you shop supply. See demand charges explained for why a supply switch alone rarely fixes a bill dominated by kW charges.

What you can shop and what you cannot

Illinois commercial customers may choose a competitive retail supplier under the Illinois switching guide. ComEd remains your delivery utility. Outages, transformers, and the demand meter stay on ComEd's side.

The benchmark is the price to compare, published on Plug In Illinois and your bill [il-plugin-ptc]. For summer 2026, that benchmark is 10.399 cents before credits.

When comparing retail offers:

Check	Why it matters
All-in vs pass-through	Some quotes exclude capacity or transmission adjustments
Contract term vs October reset	ComEd's supply changes seasonally; align your term
Early termination fee	Room expansions change load profiles
Evergreen/auto-renew	See contract fine print

CUB warned that alternative suppliers face the same market conditions and that Illinois consumers have lost about $2 billion to bad supplier deals since 2015 [cub-comed-summer-2026]. A lower sticker rate with hidden fees or a short teaser period can cost more than default supply.

Timing for cultivators

Three dates matter on a ComEd calendar:

1. June 1: Summer supply rate begins (10.399¢ through September).
2. October 1: Non-summer supply price replaces the summer figure.
3. Your contract renewal: Retail fixed rates may not align with ComEd's seasonal resets.

If you are building out canopy before summer, model supply at both the filed rate and a retail fixed quote. Compare against Illinois commercial electricity rates for context, but use your interval data if you have it.

Staggering flower-room photoperiods can shave delivery demand even when supply is expensive. That lever does not change the cents per kWh on the supply line, but it lowers the delivery portion ComEd still controls.

Bottom line for operators

ComEd's summer 2026 supply price of 10.399 cents per kWh is a real, filed benchmark [cub-comed-summer-2026]. Capacity costs in PJM drove it. CEJA credits soften June slightly. Delivery and demand remain ComEd's domain.

Before you sign a multi-year supply contract, separate the three bill buckets (supply, delivery energy, demand), compare all-in retail pricing to the price to compare net of known credits, and confirm pass-through language on PJM capacity. The goal is budget clarity through a hot summer, not a race to the lowest teaser rate on a door hanger.

POWER Act and data center cost allocation

CUB supports Illinois POWER Act (SB 4016/HB 5513) requiring data centers to bring clean power for firm service [cub-comed-summer-2026]. Long-term, successful policy could ease capacity forecasts affecting ComEd supply. Near-term, 10.399¢ remains the filed summer fact [cub-comed-summer-2026].

ComEd average 12% bill increase caveat

CUB notes 12% average bill increase with hot weather pushing higher [cub-comed-summer-2026]. Cultivation dehumidification adds moisture load on hot days, compounding weather sensitivity beyond 12%.

Alternative supplier warning history

Illinois consumers lost ~$2 billion to bad supplier deals since 2015 per CUB [cub-comed-summer-2026]. Teaser rates during capacity spikes repeat the pattern. Verify broker licenses via Illinois switching guidance.

Community solar credit interaction

CUB cites community solar savings versus utility supply [cub-comed-summer-2026]. On-site vs off-site solar for cannabis involves federal status constraints discussed in community solar for operators.

How CEJA and CFERA move the headline rate

Illinois Climate and Equitable Jobs Act (CEJA) created the Carbon Free Energy Resource Adjustment (CFERA) on ComEd supply bills [cub-comed-summer-2026]. When energy prices are high, CFERA can flip from a charge to a credit. CUB expected roughly a 1.3 cent per kWh reduction in June 2026, partially offsetting the filed 10.399 cents supply rate [cub-comed-summer-2026].

That means your effective June supply may land near 9.1 cents after CFERA even though procurement headlines cite 10.399 cents. Credits can change month to month with index inputs. Retail fixed contracts may or may not mirror CFERA treatment depending on pass-through language. Before comparing a supplier quote, ask whether CEJA-related adjustments are embedded or excluded.

Month	Filed supply	CFERA (CUB June estimate)	Net supply (illustrative)
June 2026	10.399¢ [cub-comed-summer-2026]	−1.3¢ [cub-comed-summer-2026]	~9.1¢
July–September	10.399¢	Verify on bill	Varies

PJM interconnection queue and why new solar arrives late

CUB ties the ComEd spike to PJM capacity prices and an interconnection queue backlog that slows new solar, wind, and battery entry [cub-comed-summer-2026]. Capacity payments reward existing accredited resources while new projects wait years for study and construction. Data-center load forecasts feed the same capacity market, raising the price to keep older gas and coal plants available on peak days.

Cannabis loads are tiny next to a hyperscale data center, but they sit in the same PJM zone and pay the same capacity adder embedded in default supply. You cannot opt out by industry type. The lever is contract structure (fixed all-in vs pass-through capacity) and load management on ComEd delivery tariffs you still pay after switching supply.

Block-and-index for processor-heavy campuses

Indoor flower rooms often fit fixed all-in supply because kWh is flat month to month. Extraction labs with batch ovens, chillers, and solvent recovery sometimes prefer block-and-index structures that hedge a portion of load at a fixed block price and float the remainder on day-ahead markets. ComEd's 10.399 cents summer benchmark is the comparison point for fixed offers; block-and-index requires staff who can read PJM day-ahead LMP reports and tolerate budget variance.

Review fixed vs index vs block-and-index contracts before signing. Pair supply strategy with ComEd delivery schedules and Illinois extraction facility energy if your license includes processing on the same meter.

October non-summer reset and contract alignment

ComEd's 10.399 cents applies June through September 2026 [cub-comed-summer-2026]. A non-summer supply price replaces it October 1 [cub-comed-summer-2026]. CUB expects elevated prices to continue even after the seasonal label changes [cub-comed-summer-2026].

Retail contracts expiring September 30 force a renewal decision exactly when summer kWh peaks for many grows. Contracts auto-renewing into October may reprice on evergreen terms unless you give 60-day notice per contract fine print guidance. Align notice windows with ComEd's seasonal calendar before August harvest distractions [cub-comed-summer-2026].