Alliant Energy has sent out an apology to customers for the billing process used this summer that miscalculated their usage.  Alliant spokesman Justin Foss says the summer was warmer this year, but the billing system figured in last year’s usage amounts for bills that were estimated.

Foss isn’t sure how many customers overall were impacted or how long the billing was an issue.

He says the company system would normally catch such issues.

The company says it has temporarily stopped the disconnection process for customers who are impacted by this, and  are waiving late payment fees for affected customers.