Solar and your town's electric aggregation program

Aggregation lets a city or village buy electricity supply in bulk for its residents and small businesses, who are enrolled unless they opt out. ComEd or Ameren still delivers the power, sends the bill and handles outages; only the supply price changes.

It's common. The Citizens Utility Board counts 752 aggregation programs in Illinois since 2009, with 434 active offers in August 2026: 175 in ComEd territory and 259 in Ameren territory.

Yes. CUB says alternative suppliers are required to offer net metering and to credit you at the same rate they charge you for electricity. For systems connected since 2025, those credits apply to the supply charges on your bill, not delivery. So in an aggregation program, what your exported solar earns follows the supplier's rate rather than ComEd's or Ameren's Price to Compare.

Many towns treat solar homes separately. Lake Forest, for example, doesn't switch net-metered accounts automatically and offers them a separate opt-in, warning that they may lose excess credits if they switch.

Less often than before. CUB says ComEd and Ameren net metering customers no longer lose banked credits when switching suppliers, with one exception: Ameren customers who switch from a fixed-price rate to Power Smart Pricing lose all stored credits.

Rules still vary by supplier, so Illinois Shines advises asking a new supplier whether your accumulated credits will carry over, and notes you'll need to re-enroll in net metering with a new supplier. Credits on systems connected since 2025 don't expire while you stay put.

It depends on where you live. CUB's 2026 analysis found more than 9 in 10 aggregation offers in Ameren territory cost more than Ameren's supply price, while most offers in ComEd territory were about the same or better than ComEd's. Some suburban programs simply match the utility: Lake Forest's consortium and Highland Park's program both track ComEd's rate.

Compare any offer with the Price to Compare, currently 10.1¢ per kWh for ComEd and 10.4¢ for Ameren's first 800 kWh. See the Price to Compare.

Several affluent ComEd towns now run programs priced to match ComEd's own supply rate, so joining or leaving changes little on your bill:

• [Wilmette](/solar-panels/wilmette-il): a 72-month agreement approved May 27, 2025, priced equal to the ComEd rate, starting with the September 2025 meter read.
• [Deerfield](/solar-panels/deerfield-il): a 48-month agreement approved September 15, 2025, under which participants never pay more than ComEd's monthly published rate.
• [Glencoe](/solar-panels/glencoe-il): supply for two years from February 2026, priced equal to ComEd's monthly published supply rate.

For a solar owner in these towns, the export credit works out about the same either way.

Downstate programs are more likely to use a fixed price, which can end up above Ameren's own rate. Edwardsville signed a 24-month contract starting with the June 2025 meter read at a fixed 10.82¢ per kWh, compared with Ameren's Price to Compare of 10.4¢ for October 2026–May 2027. In Bloomington and Normal, the Ecology Action Center recommended residents opt out of aggregation in 2026.

Compare your town's rate with the Price to Compare before each contract renews.

• Check your bill to see whether your supply comes from ComEd or Ameren or from your town's supplier.
• Don't opt in or switch without asking how your banked credits will be handled.
• Consider staying with the utility. CUB says it's often simpler to net meter with ComEd or Ameren, which have larger net metering departments than suppliers.
• Watch battery-plus-supply offers, which also switch your supplier. See supplier battery offers.

See also how much ComEd and Ameren pay for excess solar and why you still have an electric bill with solar.