Carbon impact evaluator

The Carbon Impact Evaluator module is designed to measure the carbon emissions associated with a website. To conduct this assessment, the module uses the CO2.js library from the Green Web Foundation, which offers two distinct methodologies for calculating emissions:

• Sustainable Web Design: This methodology is based on data transfer as an indicator of energy resource usage. It uses this data to extrapolate the site's energy consumption values as a fraction of the expected energy for a total system. This approach allows for a more detailed understanding of the environmental impact related to data traffic.
• OneByte: This methodology model calculates CO2 emissions based on the amount of data in bytes. This metric provides a direct perspective on how each byte transferred contributes to the application's carbon footprint. Flexibility is a feature of this module, as users have the option to implement both models or just one, depending on their needs.

Users can view a summary of the carbon impact of various pages by accessing the URL /carbon-impact-evaluator/table. This page contains a table that records the carbon emissions for the different pages of the site, considering only visits made after the module was installed.

Installation

Install as you would normally install a contributed Drupal module.
See: https://www.drupal.org/node/895232 for further information.

Configuration

1. Go to Configurations > Web services > Carbon Impact Evaluator Settings.
2. Activate the plugins that you wish to make available on your website.
3. Indicate whether your site is hosted by a Green Host.
4. If you have activated the Sustainable Web Design (Per Visit) option, also fill in the Datacentre Country field with the ISO alpha-3 code of the country in which your datacentre is available.
5. Structure > Block layout and add the block to the region you wich it appears.
6. In the block configuration, under the Pages section, specify that you want to hide the block on the following page: "/carbon-impact-evaluator/table". This will prevent calculations from being executed on the page containing the CO2 impact accounting table for your site.

Last update (May 9, 2025):

In our latest update (May 9, 2025), we made it possible to calculate CO2 emissions for entities such as Users and Taxonomies.

Note: If you have installed the latest version of our module but have not updated it since May 10th, we advise you to update it and run updb to update your table with the latest module fixes. For more information, you can consult these two issues:

• Call to a member function addField() on array
• Drupal\Core\Database\IntegrityConstraintViolationException: SQLSTATE[23000]: Integrity constraint violation: 1062 Duplicate entry