Gross MW of 220, and a Unit of kakrapar 1 involves what operation start?
CREATE TABLE "units" (
  "unit" text,
  "type" text,
  "gross_mw" text,
  "construction_start" text,
  "operation_start" text
);
SELECT "operation_start" FROM "units" WHERE "gross_mw"='220' AND "unit"='kakrapar 1';