CREATE TABLE table_23958917_1 (in_service_dates VARCHAR, owner_s___2009_ VARCHAR, location VARCHAR)

Name the number for service dates for hoosier energy for petersburg
SELECT COUNT(in_service_dates) FROM table_23958917_1 WHERE owner_s___2009_ = "Hoosier Energy" AND location = "Petersburg"
SELECT COUNT("in_service_dates") FROM "table_23958917_1" WHERE "Hoosier Energy" = "owner_s___2009_" AND "Petersburg" = "location"