A carbon removal buyers coalition founded by McKinsey, Google and others has backed a new approach to biomass energy that promises to provide always-on electricity while sequestering carbon dioxide deep underground.

The Frontier coalition announced this week that it would spend $41 million on 116,000 removal credits from Arbor, a startup founded by a former SpaceX engineer that’s developed a more efficient process for what’s known as bioenergy with carbon capture and storage (BECCS). The startup will generate the credits with a facility close to Louisiana’s Gulf Coast that is expected to be operational in 2028.

The deal is the latest in a flurry of recent interest in BECCS. Microsoft, by far the most active buyer of removal credits, has contracted for close to 10 million BECCS credits from projects in Norway, Louisiana and Sweden since April.

Trio of innovations

Arbor says its approach advances BECCS in three ways. Rather than burning biomass directly, the company uses a new gasifier design to convert it into syngas, a mixture of hydrogen and carbon monoxide. The gas is then sent to a specialized furnace that burns it in pure oxygen instead of air. This creates a stream of CO₂ in a liquid “supercritical” state, which is used to drive the turbine. (Conventional BECCS uses steam to do so.) Once used, the CO₂ stream is captured and piped to a geological reservoir for permanent storage.

These innovations boost the efficiency of the biomass-to-electricity energy conversion by more than 30 percent, noted Frontier. And because the waste stream contains just carbon dioxide and water, rather than the mix of gases generated by other BECCS approaches, separation of the CO₂ for storage is also cheaper. 

At present, the process is still expensive — Frontier’s is paying more than $350 per credit — but the coalition said costs could fall below $100 per ton of CO₂ removed as the technology is scaled. The fact that Arbor integrates the capture process with power generation will help cut costs as that happens, because every two- to three-fold increase in the size of the system is projected to generate a 10-fold increase in power generation and carbon removal. 

“One of the amazing features of their technology is that the output does not scale linearly with the size of the facility that they build,” said Hannah Bebbington, Frontier’s head of deployment. “That is an incredible cost saving, right as you’re thinking about the economics of the next facility.”

What counts as waste?

The promi