user: ### NOW ANSWER:
Question: Operation start of 2015 has what gross mw?
Columns: ['Unit', 'Type', 'Gross MW', 'Construction start', 'Operation start']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['Phase I', 'Phase I', 'Phase I', 'Phase I', 'Phase I']
SQL:

assistant: SELECT "Gross MW" FROM "Table" WHERE "Operation start" = '2015';