Alliant Energy customers in Iowa want to know why their electricity bills are likely going up.

Many people asked about it at a Tuesday public hearing at the Peosta Community Center. It's one of a handful meetings that Alliant is holding as part of its request to raise rates nearly 12 percent.

Alliant hasn't increased its rates in six years.

The Vice President of Alliant says this rate increase is the result of six years of investments, like power lines or new generating systems. But Iowans against the hike say they shouldn't have to front the money for those upgrades.

A 12 percent increase comes out to an average of $14 more on each month's Alliant Energy bill.

Robin Kennicker, doesn't want to pay one cent more than she already does. She was at Tuesday's meeting on behalf of her neighborhood association in Dubuque.

"They had many questions about this rate hike, but a lot of them are on fixed incomes, social security, and disability, and they're having trouble paying their childcare, or their bills," she said.

Alliant says the rate increase will cover pieces of equipment people are familiar with, and new facilities that are often out of sight.

"First the poles, the wires above ground and under ground, the transformers," Alliant Vice President Joel Schmidt said. "Also the Marshalltown generating system, which is one of the most efficient natural gas facilities in the country and it just came online."

Alliant spent $2.5 billion on those improvements to the electrical system in the last six years. It says asking users of that electricity to pay 12 percent more is a fair request.

"Not a penny more than we would need," Schmidt said.

Three people spoke in favor of the rate increase because it pays for the shift from coal to natural gas-- a cleaner energy. But others, like Kennicker, aren't convinced the new infrastructure is worth the extra cost.

"I hope the Iowa Utility Board has their hands full," she said.

The Iowa Utilities Board makes the ultimate decision on the rate increase. The board will then hold a vote in late fall or early winter.