CREATE TABLE table_13308 ("Entities" TEXT, "Country" TEXT, "Supply point" TEXT, "Voltage  ( kV ) " FLOAT, "Power  ( MW ) " FLOAT)

Which Power (MW) has a Voltage (kV) of 500, and a Country of argentina?
SELECT AVG("Power (MW)") FROM table_13308 WHERE "Voltage (kV)" = '500' AND "Country" = 'argentina'
SELECT AVG("Power (MW)") FROM "table_13308" WHERE "Country" = 'argentina' AND "Voltage (kV)" = '500'