In this section the following words have the meanings indicated. “Cogenerator” means a qualifying cogenerator or qualifying small power producer as determined by the Federal Energy Regulatory Commission under the Public Utility Regulatory Policies Act of 1978. “Electricity supplier” has the meaning stated in § 1–101 of the Public Utilities Article. This section does not apply to: a cogenerator or electricity supplier that is subject to the public service company franchise tax; or an electricity supplier that, before July 1, 1999, was not an electric company as defined in § 1–101 of the Public Utilities Article as in effect on June 30, 1999, unless the electricity supplier is an affiliate of such an electric company. Subject to the limitations in § 8–406(b)(2) of this article, a cogenerator or electricity supplier may claim a credit against the State income tax in the amount of $3 for each ton of Maryland–mined coal that the cogenerator or electricity supplier purchased in the taxable year. A cogenerator or electricity supplier may only apply the credit against the State income tax for the taxable year in which the credit was earned. The amount of the credit may not exceed the State income tax for that taxable year. The total amount of credits approved under this section shall be subject to the limitations in § 8–406(b)(2)(iv), (v), and (vi) of this article. A cogenerator or electricity supplier shall submit an application in accordance with § 8–406(b)(2)(iii) of this article in order to claim the credit available under this section.