Solar Panels

Hi There

 

I read the posts but still don't understand.

 

If I pay $30K for solar system

Credit is $9K

My taxes I owe at the end of the year is $3K

If I understand, the $9K will eliminate the $3K I would owe, leaving me with no payment to IRS for $3K?

What happens to the other $6K of the $9K I don't use please

 

Thank you 

Diane