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Rapid Energy & Climate Policy Evaluation

Compiled by the Princeton ZERO Lab to put granular analysis in the hands of policy makers, media and the general public.

The REPEAT Project provides regular, timely, and independent environmental and economic evaluation of federal energy and climate policies as they’re proposed and enacted. From Congressional legislation to proposed regulations and executive actions, the REPEAT Project provides a detailed look at the United States’ evolving energy and climate policy environment and the country’s progress on the road to net-zero greenhouse gas emissions.


Led by the Princeton ZERO Lab (Prof. Jesse D. Jenkins, PI), in partnership with Evolved Energy Research and Prof. Erin Mayfield of Dartmouth College, the REPEAT Project employs a suite of geospatial planning and analysis tools coupled with detailed macro-energy system optimization models capable of rapidly evaluating policy and regulatory proposals at politically-relevant spatial resolutions (e.g., state, county, and sometimes finer resolutions). This includes evaluation of candidate sites for wind and solar development, thermal power plant siting and repowering, and transmission expansion as well as the impacts of the nation’s energy infrastructure on air quality and public health, and changes in energy sector employment. The REPEAT toolkit reflects further development and refinement of the models and methods used in the landmark Princeton Net-Zero America Study. Data and publications are intended to provide independent, timely, and credible information and analysis for broad educational purposes, including as a resource for stakeholders, decision-makers, and the media. Funding for the REPEAT Project was provided by a grant from the Hewlett Foundation.


Preliminary Report: The Climate Impact of Congressional Infrastructure and Budget Bills

With Congress considering infrastructure and budget bills that would provide unprecedented public investments in clean energy infrastructure, clean vehicles, and other low-carbon solutions, the REPEAT Project is releasing this preliminary report on the national-scale impacts of the Build Back Better Act being considered in the House of Representatives (H.R. 5376, as reported by the Budget Committee on September 27, 2021) and the Infrastructure Investment and Jobs Act (H.R. 3684, as passed by the Senate on August 10, 2021).


Download the report for details on the impact of these pending policies on carbon dioxide emissions, clean energy and electric vehicle deployment, fossil energy use, and more. (This version, October 20, 2021.)

Addendum to Preliminary Report (11/12/21)

Since release of our “Preliminary Report: The Climate Impact of Congressional Infrastructure and Budget Bills,” on October 20th, 2021, the U.S. House of Representatives passed the Infrastructure Investment and Jobs Act ( H.R. 3684 ) on November 6th and introduced a new version of the Build Back Better Act ( H.R. 5376, RCP 117-18 ) on November 3, 2021.


There are a significant number of changes to the Build Back Better Act, which the REPEAT Project has carefully documented along with a thorough catalog of all climate and clean energy provisions in the final Infrastructure Bill in this document.

This addendum to our preliminary report compiles emissions results from our original analysis of the Build Back Better Act (‘BBB 1.0’) as reported by the Budget Committee on September 27, 2021 but without the Clean Electricity Performance Program (the most substantive single change from BBB 1.0 to BBB 2.0) as well as our initial analysis of the Infrastructure Bill impacts.

The REPEAT Project is currently modeling the updated version of Build Back Better (‘BBB 2.0’) and conducting a final analysis of the Infrastructure Bill, which will supersede results in our preliminary report and this addendum and will be released as soon as possible.


Detailed Data Portal, Coming Soon ...

REPEAT will release granular, geospatially resolved results, analysis of air quality, public health, and employment impacts, and a state-by-state data portal at this website very soon. Stay tuned!