The work of creating rules and regulations that enforce statutes is done by federal agencies. Agencies interpret and apply their governing statutes to create detailed regulations, which give specific content to statutory intent and provide procedures for implementation and enforcement.
Regulations currently in force are published in the Code of Federal Regulations (CFR). Proposed and final versions of regulations are published in the daily Federal Register before they appear in the CFR.
Energy related regulations can be issued by a number of different agencies, so a keyword search in the CFR can yield relevant results beyond the rules issued by DOE, FERC, etc.
The Department of Energy Organization Act centralized the federal government’s major energy programs. Some programs reside with other agencies, including those listed below along with the Title of the CFR where their regulations are located:
Department of Energy - CFR Title 10
Department of Energy, Federal Acquisitions Regulations System - CFR Title 48, much of Parts 904-951
Federal Energy Regulatory Commission - CFR Title 18
Nuclear Regulatory Commission - CFR Title 10
Environmental Protection Agency - CFR Title 40
Department of the Interior - CFR Title 43