There has not been a 2015 Iowa State Senate election. However, the 2014 election had several different candidates that ran for election in each district.
Those interested in finding the specific names of candidates in their districts can check the complete list of the 2014 Iowa State Senate Election candidates online at the Ballotpedia website. The candidates who won their specific offices in the 2014 election are slated to be in office from 2015 to 2017. Candidates who previously held office and decided to retire include Nancy Boettger (R), Hubert Houser (R), Dennis Black (D), Jack Hatch (D) and Sandra Griner (R).