Table schema:
CREATE TABLE table_name_44 (voltage__kv_ VARCHAR, supply_point VARCHAR, country VARCHAR, power__mw_ VARCHAR)

Question: How much Voltage (kV) has a Country of argentina, and a Power (MW) larger than 30, and a Supply point of yacyretá?
SQL: SELECT COUNT(voltage__kv_) FROM table_name_44 WHERE country = "argentina" AND power__mw_ > 30 AND supply_point = "yacyretá"