SCHEMA:
CREATE TABLE table_name_48 (commercial_operation VARCHAR, gross_capacity VARCHAR, electricity_grid VARCHAR)
USER:
Which Commercial Operation has both a Gross Capacity of 417 mw and an Electricity Grid 27.12.1971?

QUERY:
SELECT commercial_operation FROM table_name_48 WHERE gross_capacity = "417 mw" AND electricity_grid = "27.12.1971"