What Is the Coal to Solar and Energy Storage Line on a ComEd Bill?

Most lines on a utility bill are named after an accounting category. This one is named after a place.

Coal to Solar and Energy Storage buys renewable energy credits from solar farms built on the sites of power stations that used to burn coal, and it funds a grant programme for energy storage run out of the Illinois Treasurer's office. It is nine cents on a typical residential bill and it is the only line on the bill that tells you where the generation physically is.

What it cost on two real bills

Bill	Usage	Rate	Arithmetic	Printed
July 2026 billing period	953 kWh	0.009 cents per kWh	953 x $0.00009 = $0.08577	$0.09
June 2026 billing period	1,518 kWh	0.009 cents per kWh	1,518 x $0.00009 = $0.13662	$0.14

The rate comes from ComEd's 9th Revised Informational Sheet No. 63, the supplement to Rider CTS, effective April 18, 2026. It applies from the May 2026 monthly billing period through September 2026.

The rate for April 2026 was different, for one month only

The same sheet carries a single month window above the current one. For the April 2026 monthly billing period alone, the Coal to Solar Adjustment was 0.006 cents per kWh. It then rose by half, to 0.009, for May onward.

A one month rate window is unusual and it is not a mistake. It falls out of the way the rider handles reconciliation, which is covered below.

What the filed tariff says it is for

Rider CTS gives effect to subsection (c-5) of Section 1-75 of the Illinois Power Agency Act and subsection (i-5) of Section 16-108 of the Public Utilities Act. It collects two different things through one bill line.

Renewable energy credits from converted coal sites. The rider's stated purpose is to recover ComEd's cost of procuring renewable energy credits from new renewable energy facilities installed at or adjacent to the sites of electric generating facilities that, as of January 1, 2016, burned coal as their primary fuel source.

That date is doing real work. It is not a general renewables charge. It is a charge for credits from projects on a defined set of former coal sites, fixed by where coal was being burned on a particular day in 2016.

Energy storage grants. The rider separately collects what it calls Energy Storage Grant Costs, defined as the amount ComEd is required to provide to the Illinois Treasurer to fund grant payments made each year by the Department of Commerce and Economic Opportunity for eligible energy storage facilities.

That half of the line is not ComEd's money and does not stay with ComEd. It is billed, collected and remitted to the state.

The rider runs on two calendars at once

This is the part that explains why the rate windows look strange, and it is not derivable from the bill.

The rider defines a Delivery Year as June 1 through May 31. It defines a Recovery Year as January through December. Costs are incurred against the first calendar and collected against the second, and the two do not line up.

Then there is the balancing rule. The Coal to Solar Balancing Amount, the term that trues up what was over or under collected, is fixed at zero dollars for the April through September monthly billing periods. It only carries a value for the October through March periods, determined by August 1 each year.

Read plainly: the charge you pay in summer contains no correction for past errors. The charge you pay in winter carries all of it. Half the year is a forecast and half the year is a forecast plus a settlement.

Who sets the rate and how it moves

ComEd computes it and files it with the ICC for informational purposes. The equation divides the sum of credit costs and storage grant costs by forecast usage, then adds two adjustment terms with their own denominators.

The two correction terms are worth naming because they are where money comes back:

• RECOA, the Renewable Energy Credit Ordered Amount. Any adjustment directed by the ICC, or determined by ComEd, to refund or collect for errors in a previously applied credit charge. It carries interest at the rate the ICC sets under 83 Illinois Administrative Code Section 280.40(g)(1).
• ESGOA, the same thing for the storage grant half.

Both may be amortised across multiple future adjustments rather than refunded at once. If ComEd gets the number wrong, the correction arrives spread over later bills, with interest, rather than as a credit you would notice.

Informational Sheet No. 63 is on its 9th revision, and it changed twice in 2026, effective March 18 and April 18.

Can it be avoided?

No.

Rider CTS states that it is applicable to all retail customers, across Rates BES, BESH, BEST and RDS, which between them cover essentially everyone ComEd serves. It is charged per kilowatt hour delivered, so switching to a retail electric supplier does not remove it.

Installing your own solar does not exempt you either. The charge follows delivered kilowatt hours, so it falls as your consumption from the grid falls, and for no other reason.

What this page was checked against

Both. The mechanism, the statutory basis, the January 1, 2016 coal test, the Illinois Treasurer remittance and the seasonal balancing rule are quoted from Rider CTS, Sheets No. 601 through 605 of ComEd's filed Schedule of Rates. The rate is the filed value on the 9th Revised Informational Sheet No. 63 and is confirmed to the cent by two unrelated bills.

The other lines on the same bill are covered in every line on a ComEd bill, explained.