Microsoft will pay to extract carbon from burning wood

Microsoft backed a major plan to capture carbon dioxide emissions from a wood-burning power plant. Today, the tech giant announced a deal with Danish energy company Ørsted to buy credits representing 2.76 million metric tons of carbon dioxide captured at Ørsted’s Asnæs power station over 11 years.

According to a press release from Ørsted, the deal is one of the largest ever by any company to reduce carbon dioxide emissions. The move should help Microsoft meet its goal of becoming carbon negative by 2030, at which point the company will be removing more planet-warming carbon dioxide from the atmosphere than it generates through its operations.

But the technology to capture carbon dioxide emissions is still nascent, and some environmental groups and researchers are skeptical that the strategy Microsoft helped fund could be an effective way to combat climate change. Without Microsoft’s support, Ørsted would not have been able to install carbon capture devices at its power plant. “Both the Danish state subsidy and Microsoft’s contract were necessary to make this project viable,” Ørsted’s declaration says,

With Microsoft’s help, Ørsted was able to secure an even larger, 20-year contract with the Danish Energy Agency (DEA) to capture CO2 emissions from Asnæs in western Zealand and a second power plant near Copenhagen. Once the carbon capture devices are installed, they should be able to capture a total of 430,000 metric tons of CO2 annually by 2026. For comparison, it is roughly Equal How much CO2 does a gas-fired power plant emit in a year?

However, these power plants burn wood chips and straw, also known as “biomass”. And burning biomass, which can include agricultural waste and other plant material, is controversial as a sustainable energy source. EU counts biomass It is the largest source of renewable energyBut most of the wood burned came from trees cut down in forests. Europe And this southeast us, Ørsted says the wood chips burned at its Asnæs power station “come from sustainably managed production forests and contain the remains of trimming or felled trees.”

How is burning trees considered good for the environment? After all, wood also releases CO2 when it burns. The reasoning is that the trees or crops used to create biomass naturally capture and store CO2 while they are alive. So if you replant trees or plants, you can potentially have a fuel that is carbon neutral.

Ørsted is going a step further by adding technologies that can filter CO2 from the smokestacks of its power plants, preventing it from rising up into the atmosphere. By doing so, it believes that power plants burning biomass will become carbon negative. They plan to bury the excess carbon dioxide captured at the bottom of the North Sea and sell credits to Microsoft representing each ton of CO2. Microsoft can then use those credits to claim that it has canceled out some of its greenhouse gas pollution.

If this all sounds like a difficult balancing act, it is. Previous research has found that burning woody biomass can cause more CO2 emissions than what is captured, This is because only capturing the smokestack emissions doesn’t count For all the pollution that can come from cutting down trees and transporting wood. Also, it may take a long time for trees or plants to become mature enough that people can rely on them to reduce significant amounts of CO2.

“We think the details are important,” Philip Goodman, carbon removals portfolio director at Microsoft, says in an email. ledge, Goodman says an effective carbon capture project would need to use biomass “harvested from appropriate areas” and account for all of its “process” emissions. Microsoft declined to say how much it would pay Ørsted for carbon removal credits for this particular project.

Microsoft has been making some bold bets on climate tech and clean energy technologies lately. Last week, it announced plans to buy electricity from an upcoming nuclear fusion power plant — even though some experts don’t think such a state-of-the-art power plant could realistically be developed for several more decades. Microsoft has also paid a Swiss company called Climeworks to filter CO2 from the air.