BOARDMAN — After a dozen years operating data centers in Eastern Oregon, Amazon says it has a deal to buy renewable energy to help power them.

The Seattle company announced recently it has started working with the local power utility, Umatilla Electric Cooperative, to choose the electricity supply for its huge data center operations near the communities of Boardman and Hermiston. It said that enables the company to choose some renewable power for its installations.

Amazon’s announcement follows reporting by The Oregonian on how the company’s growing footprint in Eastern Oregon has contributed to an enormous surge in regional carbon emissions, and an unsuccessful push by climate activists and state lawmakers to require large data centers to transition to clean power.

Amazon says it has been pursuing renewable energy for its Oregon data centers for some time but has only now been able to secure contracts to provide it.

The company says its wholesale power contracts prevent it from saying how much renewable energy it’s buying. So the impact of its new deal with Umatilla Electric won’t be clear until next year, when the utility discloses updated information about its 2023 energy mix to Oregon regulators. (The utility did not respond to questions about its new arrangement with Amazon.)

But Amazon claims its calculations show its Oregon data centers already are “powered with at least 95% renewable energy.” The company maintains that large, clean-energy projects it has built in California and Arizona are compensating for the rapid increase in the carbon impact of its operations near Boardman and Hermiston.

“We’re adding renewable energy to the same grid where we operate,” said Charley Daitch, director of energy and water for Amazon Web Services, the company’s data center business.

Though Amazon doesn’t disclose the power sources it uses to arrive at that 95% figure, the company says it uses an outside auditor to verify its claims and it publishes the formula it uses to arrive at its conclusions.

That’s not enough for Joshua Basofin, of Climate Solutions Oregon, an environmental advocacy group that helped lead the campaign for Oregon’s clean energy bills. Without more disclosure, he said it’s impossible to evaluate Amazon’s climate claims.

Big data centers like the ones Amazon operates in Eastern Oregon use as much power as small cities to run their high-performance computers and keep the machines cool.

Most of the data centers in Eastern Oregon are exempt from state clean-power requirements state lawmakers approved in 2021, though, because the legislation exempted Umatilla Electric and other consumer-owned utilities from the bill’s major provisions.