This bill establishes the Southwestern Power Administration Fund within the Treasury of the United States, centralizing the financial resources for the Southwestern Power Administration (SWPA). The fund will consolidate various existing funding streams, including all SWPA receipts, appropriations, and transferred unexpended balances from previous continuing, advanced payment, and offsetting collections funds. Amounts in this fund will remain available until expended, providing continuous financial support for the agency's critical operations. The Secretary of Energy, acting through the Administrator, is authorized to use these funds for essential activities such as the operation and maintenance of power transmission facilities , marketing electric power, and the construction or acquisition of new transmission assets, alongside administrative expenses related to SWPA's statutory duties. The bill grants the Secretary the authority to incur obligations in advance of appropriations, enhancing financial flexibility for projects. Annually, any excess amounts in the fund must be transferred to the Treasury as miscellaneous receipts, ensuring fiscal accountability. Conforming amendments are also included to integrate the new fund with existing statutory provisions and repeal obsolete funding mechanisms.