CREATE TABLE table_15580 ("Transmitter Site" CLOB, "Frequency" CLOB, "Power" CLOB, "RDS Name" CLOB, "PI Code" CLOB, "Area" CLOB)

What is the frequency with 900w power?
SELECT "Frequency" FROM table_15580 WHERE "Power" = '900w'
SELECT "Frequency" FROM "table_15580" WHERE "Power" = '900w'