A Midwest tech nonprofit is helping Google implement a big idea aimed at bringing more clarity and precision to renewable energy purchases.

As a growing list of companies tries to make good on climate commitments, many are using renewable energy certificates, or RECs, to meet their voluntary targets. The certificates are intended to capture the social and environmental benefits of 1 megawatt-hour of wind or solar power. In addition to selling the electricity they generate, producers can offer RECs to companies that want to claim credit for the projects’ environmental benefits. The concept has been around for a couple of decades and is used for complying with state requirements or voluntary targets as an alternative to building on-site generation.

Google already offsets all of its annual electricity consumption with renewable energy purchases. The reliance on RECs to make claims like these, however, can obscure a mismatch between a company’s actual energy use and the renewable generation supported by its certificates. Buying certificates associated with overnight wind power could in theory be used to justify continued business-as-usual electricity during the daytime. 

A small but growing number of organizations are now advocating for more granular data on RECs that would insulate them from such criticism and help reduce emissions. In September, Google pledged by 2030 to match all of its energy use with carbon-free power for every hour of every day, a concept known as 24/7 clean energy.

“Achieving 24/7 carbon-free energy means we will have clean energy available for every hour on every grid — completely eliminating carbon emissions associated with Google’s electricity use,” the tech giant said in a white paper. 

In January, Google began implementing that vision through a partnership with a Minneapolis-based nonprofit called M-RETS (formerly Midwest Renewable Energy Tracking System), which runs a platform that tracks environmental certificates. The organization has created a new product called an hourly REC that includes information on when renewable power was generated, allowing companies to match offsets with their hours of operation.

M-RETS CEO Ben Gerber said challenges remain, including gathering and verifying data and gaining market consensus on hourly claims. The hope is that the time-based RECs will eventually help other organizations meet similar climate goals. Des Moines, Iowa, for example, recently passed a resolution calling for 24/7 clean energy citywide by 2035.

Greg Miller, a Ph.D. student at the University of California-Davis who studies REC markets, said he thinks the time-based products will be useful for aligning generation with organizations’ energy use. The next frontier might be geography-based credits that take into account whether the power was generated on the same grid as the customer.

“If we want to get across the finish line, which is a full and complete transition to a carbon-free electric grid, we need to make sure that we have renewable energy that’s available in times and places that we need it,” Miller said.