; (2) in calendar year 2030 and each subsequent calendar year, such percentage shall be not less than 40 percent of the total electric energy sold at the retail level in the United States; and (3) in calendar year 2050 and each subsequent calendar year, such percentage shall not be less than 80 percent of the total electric energy sold at the retail level in the United States. (b) Consultation The Secretary shall carry out this section in consultation with the Administrator of the Environmental Protection Agency. (c) Subsequent increases Upon petition or upon the Secretary’s own initiative, the Secretary may increase the percentage required by subsection (a)(2). (d) Rule of construction Nothing in this section shall be construed to preempt or limit State actions to enhance renewable energy generation or energy efficiency. . II ENERGY EFFICIENCY 201. National energy efficiency standard Title VI of the Public Utility Regulatory Policies Act of 1978, as amended by section 101 of this Act, is amended by adding at the end the following: 611. National energy efficiency standard (a) In general The Secretary shall promulgate regulations in accordance with this section setting end-user savings targets for retail electric energy and natural gas suppliers. (b) Consultation The Secretary shall carry out this section in consultation with the Administrator of the Environmental Protection Agency. (c) Requirements With respect to targets under subsection (a): (1) The targets shall require each supplier to secure annual savings of a set percentage of the supplier’s most recent year’s sales to retail customers. (2) The savings shall be achieved through end-use efficiency improvements at customer facilities. (3) The targets— (A) for retail electric energy suppliers shall increase gradually from 0.25 percent of sales in 2020 to 1.5 percent of sales in 2025 and each year thereafter through 2030