; and (ii) increase the performance standards by regulation if the Secretary determines that additional cost-effective energy efficiency potential is achievable, taking into account the requirements described in paragraph (3)(C). (B) Lead time If the Secretary revises performance standards under this paragraph, the regulations shall provide adequate lead time to ensure that compliance with the increased performance standards is feasible. (5) Delay of submission for first reporting period (A) In general Notwithstanding paragraphs (1) and (2), for the first reporting period, the Secretary may accept a request from a retail electricity supplier or a retail natural gas supplier to delay the required submission of documentation of all or part of the required savings for up to 2 years. (B) Plan for compliance The request for delay under subparagraph (A) shall include a plan for coming into full compliance by the end of the second reporting period. (6) Applying unused savings to future years If electricity savings or natural gas savings achieved by a retail electricity supplier or retail natural gas supplier in a year exceed the applicable performance standard specified under this subsection, any savings in excess of the performance standard may be applied toward performance standards specified for any of the 2 immediately subsequent compliance years. (d) Transfers of electricity or natural gas savings (1) Bilateral contracts for savings transfers Subject to the limitations of this subsection, a retail electricity supplier or retail natural gas supplier may use electricity savings or natural gas savings purchased pursuant to a bilateral contract from another retail electricity supplier or retail natural gas supplier, a State, or a third-party efficiency provider to meet the applicable performance standard under subsection (c). (2) Requirements Electricity savings or natural gas savings purchased and used for compliance under this subsection shall be— (A) measured and verified in accordance with subsection (e)