We really can't answer without more details. For example, if you would have owed $3000, but you got $1500 back, then you really used up $4500 of the credit.
If you did not use all the credit in 2021, the amount of carry forward will be listed on line 16 of your 2021 form 5695. When you prepare your 2022 return, run the home energy efficient improvements interview because even if you did not make additional improvements, this interview is where you will report your credit carry forward from your 2021 form 5695.
