d. Notwithstanding paragraph "a", a taxpayer who owns or leases a new electric power generating plant and who has no other operating property in the state of Iowa except for operating property directly serving the new electric power generating plant as described in section 437A.16 shall pay the replacement generation tax associated with the allocation of the local amount to the county treasurer of the county in which the local amount is located and shall remit the remaining replacement generation tax, if any, to the director according to paragraph "a" for remittance of the tax to county treasurers. The director shall notify each taxpayer on or before August 31 following a tax year of its remaining replacement generation tax to be remitted to the director. All remaining replacement generation tax revenues received by the director shall be deposited in the property tax relief fund created in section 426B.1, and shall be distributed as provided in section 426B.2. If a taxpayer has paid an amount of replacement tax, penalty, or interest which was deposited into the property tax relief fund and which was not due, all of the provisions of section 437A.14, subsection 1, paragraph "b", shall apply with regard to any claim for refund or credit filed by the taxpayer. The director shall have sole discretion as to whether the erroneous payment will be refunded to the taxpayer or credited against any replacement tax due, or to become due, from the taxpayer that would be subject to deposit in the property tax relief fund.