EVANSTON, Ill. (CBS) — Residents of 75 Cook County communities will have the chance next month to vote for lower electric rates. The process is known as “electricity aggregation” — and a 2007 state law requires voter approval.

Evanston city sustainability coordinator Catherine Hurley said the aggregation process allows municipal officials to negotiate on behalf of all of a community’s residential and small business customers for one, lower rate — instead of paying what ComEd charges.

“The alternate suppliers are incentivized to give a lower price, because they can switch over a lot of customers at the same time,” she said. “It’s like buying in bulk.”

LISTEN: WBBM Newsradio’s Bob Roberts reports

Typically, Hurley said, the discount a community can negotiate is far steeper than those offered by alternate suppliers to individual customers.

Statewide, 130 communities could vote on such referenda next month.

The website www.pluginillinois.org indicates that 19 communities approved similar referenda last year, with savings in some communities of more than 25 percent.

In all, the site indicates that 261,000 residential customers have made a switch; some through aggregation and some through individual opt-out contracts.

But there is possible fallout for those who stick with ComEd, should enough communities approve aggregation contracts. In that case, ComEd could move to have the Illinois Commerce Commission, the body that regulates utilities in the state, declare the residential and small business markets “officially competitive.”

That means customers still buying power from ComEd could be subjected to spot-market, month-to-month fluctuations in prices, instead of the firm prices they have typically seen.

The earliest that could happen is 2013.

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