The Open Grid Emissions Initiative seeks to fill a critical need for high-quality, publicly-accessible, hourly grid emissions data that can be used for GHG accounting, policymaking, academic research, and energy attribute certificate markets. The initiative includes this repository of open-source grid emissions data processing tools that use peer-reviewed, well-documented, and validated methodologies to create the accompanying public dataset of hourly, monthly, and annual U.S. electric grid generation, GHG, and air pollution data. Data Structure data/downloads contains all files that are downloaded by functions in load_data data/manual contains all manually-created files, including the egrid static tables data/outputs contains intermediate outputs from the data pipeline... any files created by our code that are not final results data/results contains all final output files that will be published Release Notes The 2019-2021 data archived here was created by v0.2.1 of the Open Grid Emissions Initiative, archived on Zenodo here. For a summary of what's new in the 2019-2020 v.0.2.1 data, see the v0.2.1 release notes. Using the archived files The outputs and results files have been saved as separate zip folders for each year. We did not archive the manual or downloads folder since the manual files are archived as part of the v0.2.1 code release, and downloading these files using v0.2.1 of the code should return versioned results.