The increase will have to be approved by the PSC, the Missouri Public Service Commission. The process will involve public hearings, at which consumers can voice their concerns, and a review by the under funded PSC of documents Ameren Missouri will submit to prove that it needs the rate increase.
If the past few years are any guide, Ameren will receive between 60 and 70% of it's request, which would result in a rate hike in the 9 to 10% range. Ameren and the PSC know this going into the approval process.
That process has become a charade in which Ameren inflates it's request so it can get what it wants. In the end, the PSC will claim that it trimmed the rate request down to protect consumers and Ameren will pretend to be upset that it didn't get all of the increase it asked for.
Since 2007, Ameren's electric rates have increase 31%. The new rate, when (not if) it is approved, will likely push that to 40% in rate increases over the past 5 years. Not bad in a poor economy when energy consumption has been relatively flat. I'm just glad that Ameren gets most of their energy from "cheap coal". I'd hate to see how much we would pay if they were using those expensive renewable energy sources.