Alliant Energy lost a controversial bid to charge Iowa customers who decline to have smart meters used to track their electric use.

The Iowa Utilities Board Wednesday rejected Alliant's request to charge a $15 monthly fee to customers who want to opt out of the utility's smart meters.

The board directed Alliant to file a revised request that allows customers to opt out of smart meters without charging them fees. Alliant already charges customers for meter-reading services in its current rates, the board said.

The order doesn't prevent Alliant, however, from seeking a future charge or fee from customers who opt out in a broader rate case, the board said.

The utility began installing smart meters for Iowa customers in 2017 as part of the utility's effort to upgrade its electric and natural gas distribution system.

The smart meters enable the utility to detect outages faster and provides customers better information about usage, among other advantages.

Justin Foss, an Alliant spokesman, said most of its customers are comfortable with using the new smart meters.

Alliant subsidiary Interstate Power & Light has about 710,000 customers.

About 2,000 customers, mostly in Decorah, Cedar Rapids and Fairfield, wrote the state utility board opposing the proposal. They cited cost, privacy and health concerns with the meters.

Iowa's consumer advocate said Alliant's proposal was costly and "burdensome and onerous for customers who wish to opt out" of the smart meter program.

Alliant's proposal required customers to read their meters themselves within four days of a required date, and they faced being added to the smart meter program if they missed two monthly readings.

The requirements set up customers for failure, a filing from March Schuling, the state consumer advocate, said.

Schuling argued that Alliant customers should be allowed to keep analog meters instead of being required to use digital or smart digital technology.

The Iowa Utilities Board agreed, recommending Alliant allow customers to use existing analog meters until they need to be replaced.