Any balance of proceeds of sale of said bonds and federal moneys added to the state moneys available for the project in excess of the costs of the project shall be immediately reported to the Secretary of the Office of Policy and Management. Net earnings on investments of proceeds, accrued interest and premiums on the issuance of such bonds after payment therefrom of expenses incurred by the Treasurer or State Bond Commission in connection with their issuance, and any balance reported as in this section above provided, shall be deposited to the credit of the General Fund.