CREATE TABLE table_name_72 (capacity__mw_ NUMBER, state_province VARCHAR2)

What is the total capacity (MW) of the windfarm located in the state/province of Gansu?
SELECT SUM(capacity__mw_) FROM table_name_72 WHERE state_province = "gansu"
SELECT SUM("capacity__mw_") FROM "table_name_72" WHERE "gansu" = "state_province"