There's literally power in numbers.

At least that's the hope of at least 148 cities, villages and counties across Illinois that have put referendums on local ballots this spring, hoping voters will authorize local officials to pool their power purchases to extract lower electricity prices.

The municipalities, including Belleville, Alton, Collinsville and Granite City, seek to take advantage of a state law passed in 2007 that allows communities to buy electricity in bulk -- and perhaps finally realize benefits of electric deregulation in a way that most residential customers so far have not.

"Competition is finally hitting the residential marketplace with full fury," said Arlene Juracek, acting director of the Illinois Power Agency, a state office that buys power for the state's investor-owned utilities and also advises municipalities looking to shop for electricity providers. "It means the marketplace is really working."

The communities are following the lead of 19 cities in northern Illinois that have already defected from ComEd and are realizing savings of 20 percent to 30 percent on the energy portion of their electric bills, which makes up about two thirds of the overall bill. The rest is the cost of delivering power to homes and businesses via poles and wires.

Among those already benefiting is the city of Morris, an exurb of Chicago, that cut the energy portion for most of its 13,600 residents electricity bills by an average of 30 percent beginning this month through a contract with FirstEnergy Solutions -- a move that's expected to save households an average of $200 a year.

Richard P. Kopczick, the city's mayor since 2001, went in hoping save 18 percent. "When we got 30, I was ecstatic," he said.

Some residents remain skeptical, Kopczick said. Some are suspicious of anything that government does. Others are loyal to ComEd, a big employer in the region. But he thinks lower electricity bills will eventually win them over.

"When you see that your neighbor's lights are just as bright as yours, and his house is just as cool, and he's paying less than you are for the same thing, you start scratching your head," he said.

BULK-BUYING POWER

Illinois passed a law deregulating the state's retail electricity markets in 1997, a measure expected to bring consumers lower electric rates and better service.

And for most commercial and industrial electricity consumers, it already has. More than 80 percent of big electricity users now buy power from alternative suppliers. But the vast majority of residential and small business customers, especially downstate, are still tethered to incumbent utilities.

Even though consumers across the state now have electricity suppliers competing for their business, much like they do for phone, Internet and other services, many see aggregation as an easier alternative that should yield bigger savings.

For a city to shop for its residents power, they must get voter approval through a ballot measure. The referendums give consumers the right to opt out of the arrangement if they choose, meaning they can remain with the existing utility or shop for a power deal on their own.

The referendums give approval for aggregators, or consultants working on the municipality's behalf, to solicit bids for a new energy supplier.

Nothing else changes. Electricity is still delivered to homes and businesses by the same utility network of poles and wires. Consumers continue to be billed by those same utilities. And if the lights go out, they call the utility, not the energy provider.

In fact, Ameren doesn't care if cities broker deals with other energy suppliers since the utility spun off its power plants into a separate company when Illinois restructured its electric markets.

TIMING IS MONEY

Good timing is a a key reason aggregation has worked so well and cities like Morris have been able to achieve such big savings.

Some of the electricity supplied today by utilities like Ameren Illinois and ComEd was purchased several years ago under higher-priced long-term contracts. Since then, a sluggish economy and a corresponding boom in domestic natural gas production have weakened market prices for electricity. That allows electricity suppliers to enter new contracts at much lower prices.

Buying in bulk also helps. Just as a large corporation gets a better deal on office supplies than a solo shopper at Office Depot, cities that shop on behalf of thousands of accounts can get a better deal than individual homeowners.

What's more, in each case municipalities are working with consultants such as New York-based Good Energy, which then compiles the electricity accounts from multiple cities, villages and counties to form an ever bigger buying pool, said Charles de Casteja, the company's managing partner.

Selling in bulk also helps suppliers that want to poach accounts from Ameren, since it's cheaper to market services to one consultant buying power on behalf of tens of thousands of consumers than to advertise and sign them up individually.

Good Energy, which has an office in Peoria, is the largest buying group in the state, representing dozens of cities, villages and counties -- many of them in Ameren's service territory, including Collinsville, Granite City and Glen Carbon. For each, the company is responsible both for soliciting bids from power suppliers and marketing to residents ahead of the spring referendum.

These consultants bear all of the costs and risk, making money only if the referendum succeeds and the city chooses an alternative supplier. In that case, it profits from the difference between the new and old electricity prices, with most of the benefits flowing to consumers.

"They're putting their money upfront," said John Miller, Collinsville's mayor. "We're paying nothing. They guaranteed us they would save us money, and if they guaranteed it, I don't see where we could go wrong."

Miller expects Collinsville residents will be able to save 20 percent on the energy portion of their electricity bills. "Even if we can only save them 10 or 15 percent, it's a savings," he said. "Today, everything helps. I think it's a win-win."

LOOKING AHEAD

It remains to be seen whether big savings will remain when higher priced utility power contracts expire next summer.

Juracek of the Illinois Power Agency believes the discounts of 20 to 30 percent won't last, but more moderate savings will.

"The headroom over the next two years is going to get smaller," she said.

David Kolata, executive director of Citizens Utility Board, a Chicago-based consumer advocacy group, said there's no harm in cities shopping for a better electricity price, and there should be opportunities to save for the next year or 16 months. Beyond that, when more expensive power supply contracts with utilities roll off, opportunity to save becomes less obvious.

"I think the jury is still out," he said. "Whether we'll see lasting savings for consumers is very much an open question."

That's fine with Kopczik, the Morris mayor.

"If we can't get anything cheaper than ComEd," he said, "we just go back."