Any application for electrical power plant certification filed pursuant to ss. 403.501403.518 shall be processed under the provisions of the law applicable at the time the application was filed, except that the provisions relating to cancellation of the certification hearing under s. 403.508(6), the provisions relating to the final disposition of the application and issuance of the written order by the secretary under s. 403.509(1)(a), and notice of the cancellation of the certification hearing under s. 403.5115 may apply to any application for electrical power plant certification.