Heroku uses postgres, make sure you are using postgres in development as well.
use the ILIKE postgres case insensitive version of LIKE
combined_scope.where("name ILIKE ?", "%#{word}%")
http://www.postgresql.org/docs/9.1/static/functions-matching.html
The key word ILIKE can be used instead of LIKE to make the match case-insensitive according to the active locale. This is not in the SQL standard but is a PostgreSQL extension.