Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_name_64 (year_commissioned INTEGER, average_annual_output__million_kwh_ VARCHAR, installed_capacity__megawatts_ VARCHAR)

### Question ###
What is the earliest Year commissioned wiht an Average annual output greater than 58 and Installed capacity of 20?

### Accurate SQL ###

SELECT MIN(year_commissioned) FROM table_name_64 WHERE average_annual_output__million_kwh_ > 58 AND installed_capacity__megawatts_ = 20