The REWIRE Act seeks to accelerate the modernization and expansion of the nation's electric grid, primarily by facilitating upgrades within existing infrastructure. A key provision establishes a categorical exclusion under the National Environmental Policy Act (NEPA) for activities that increase grid capacity within existing rights-of-way or on previously disturbed land. This exclusion applies to various upgrades, including reconductoring and the installation of grid-enhancing technologies, aiming to streamline environmental review processes.

To further incentivize grid improvements, the bill mandates the Federal Energy Regulatory Commission (FERC) to improve the return on equity for investments in advanced transmission conductors. This financial incentive is designed to encourage utilities to adopt more efficient and higher-capacity wiring. Additionally, the Act amends the Energy Policy and Conservation Act to include reconductoring with advanced conductors and grid-enhancing technologies as eligible activities for State Energy Programs, promoting their widespread implementation.

The legislation also focuses on enhancing grid planning and providing practical support for implementation. It directs the Secretary of Energy to establish a program through National Laboratories to develop probabilistic models for transmission planning, resource adequacy, and integrated resource planning, considering various uncertainties. Furthermore, the Secretary must create an application guide and offer technical assistance to eligible entities, such as utilities and developers, to aid in the adoption and deployment of advanced transmission conductors and grid-enhancing technologies.