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_239 ( "Power Source" text, "Number of Generators" real, "Power Capacity (GW)" text, "% of total Capacity" text, "Capacity factor" text, "Annual Energy (billion kWh)" text, "% of annual production" text )

### Question ###
What is the number of generators where the power capicity is 78.7?

### Accurate SQL ###

SELECT COUNT("Number of Generators") FROM table_239 WHERE "Power Capacity (GW)" = '78.7'