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_19258 ( "AGR Power Station" text, "Net MWe" real, "Construction started" real, "Connected to grid" real, "Commercial operation" real, "Accounting closure date" real )

### Question ###
How many power stations are connected to grid at Heysham 2

### Accurate SQL ###

SELECT COUNT("Connected to grid") FROM table_19258 WHERE "AGR Power Station" = 'Heysham 2'