Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_23958917_1 ( in_service_dates VARCHAR, owner_s___2009_ VARCHAR, location VARCHAR )

### Question ###
Name the number for service dates for hoosier energy for petersburg

### Accurate SQL ###

SELECT COUNT(in_service_dates) FROM table_23958917_1 WHERE owner_s___2009_ = "Hoosier Energy" AND location = "Petersburg"