The increasing interest in water stewardship is creating a need for more comprehensive methods of water quantification to disclose and manage impacts associated with water use. Water use during electricity generation represents one of the largest sources of water withdrawals globally.

Further, although accounting for water withdrawals and consumption is the first step toward identifying water risks and opportunities, there is limited information on how to account systematically for water use during the generation of purchased electricity.

In response, World Resources Institute (WRI) and WSP USA have developed accounting and reporting principles and a method to measure water use in the generation of electricity that an organization purchases. These are included in a newly published guidance document, “Guidance for Calculating Water Use Embedded in Purchased Electricity.” The guidance was developed by engaging key stakeholder groups and building on greenhouse gas reporting principles, relevant scientific research, and existing data.

This working paper proposes the first comprehensive approach to calculate water withdrawals and consumption associated with purchased electricity. It provides the first international country-level and U.S. subnational-level water use factors detailing the grid average water withdrawal and consumption resulting from a unit of electricity consumption.

The method is designed for all organizations interested in measuring water use and the impacts, risks, and opportunities associated with purchased electricity. It can help assess the upstream water impacts of operational decisions.

For example, water-cooled and air-cooled HVAC systems have different impacts on an organization’s direct water use. In addition, because of their differing electricity consumption, these systems also have different impacts on the water used in electricity generation. The new guidance allows organizations to quantify more comprehensive water impacts as they consider such decisions.

WRI and WSP look forward to engaging with organizations who seek to apply this guidance to their operations to further their water stewardship efforts.

Click here to download the guidance document.