CREATE TABLE table_41556 ("City of license" TEXT, "Identifier" TEXT, "Frequency" TEXT, "Power" TEXT, "Class" TEXT, "RECNet" TEXT)

What is the identifier that has 50,000 watts of power?
SELECT "Identifier" FROM table_41556 WHERE "Power" = '50,000 watts'
SELECT "Identifier" FROM "table_41556" WHERE "Power" = '50,000 watts'