UPDATED 03/20/12 10:42 a.m.

CHICAGO (CBS) — In addition to presidential and congressional races, many voters in many communities across the state Tuesday are thinking about their electric bills.

As WBBM Newsradio’s Regine Schlesinger reports, over 300 suburbs and towns are letting voters decide whether to negotiate to buy bulk power through a program known as municipal utility aggregation.

LISTEN: WBBM Newsradio’s Regine Schlesinger reports

Chicago area suburbs from Chicago Heights to Wilmette are considering the move. Some of the largest suburbs are also among those with referenda, including Aurora, Waukegan, Evanston and Elgin.

Entire cities and towns – and in some cases, several municipalities banding together – are looking to increase their bargaining power to lower what residents and small businesses pay for electricity on contracts locked in long ago.

New Lenox Mayor Tim Baldermann says his village approved municipal utility aggregation last year, and now, residents are saving up to $200 a year on their bills.

“Not only is there definitely a financial benefit for the residents of the community that support it, but if, for whatever reason, you chose not to participate, you can opt out at no cost,” Baldermann said.

The Citizens Utility Board says the wave of ballot initiatives follows the experience about 20 municipalities that have already cut their own deals, saving customers about $14 per month on their bills.

But CUB says the savings might just be temporary. The long-term contracts are due to expire next year, and after that, ComEd and Ameren are expected to lower prices.