Alliant Energy has filed a request with the Iowa Utilities Board to increase its electric rates by 11.6 percent.

The president of Alliant Energy’s Iowa utility, Interstate Power and Light, Doug Kopp, says the company has not raised electric rates for six years. “Over that period of time we’ve made significant investments, including the grid and also our Marshalltown generating station…which has just come on line. It’s a natural gas combined-cycle plant with allows us to be very, very efficient,” Kopp says.

He says they’ve spent around $2.5 billion in the improvements to the system, and the rate increase allows them to recover those costs. Kopp says the customers have benefited from the money invested in the electric system.

“Our duration of outages is better than six years ago. Our frequency of outages is lower than six years ago,” he says. Kopp says the new Marshalltown plant gives them more flexibility in producing power right away when needed, and he says it is more environmentally friendly.

Alliant has around 500,000 electric customers in Iowa.

“The average customer bill is about $114 a month and they would see an approximately $14-a-month increase,” Kopp says. The first part of the rate request creates an interim rate increase on April 13th and then state regulators have to decide if they will grant the full increase.

He says there will be some customer comment hearings in late May or early June hosted by the IUB to give customers a chance for input on the rate increase request. Then there would be a hearing in the fall where the IUB hears the arguments for and against the rate increase. The rate increase would go into place in 2018, depending on the ruling from the IUB.

Kopp says there are some tax credits and transmission refunds that will reduce the impact of the rate increase in 2017 and 2018. Alliant customers will be getting information on the proposed rate increase in their monthly bills.