California-based Windfall Bio has ceased operations and is auctioning off substantial lab and bioreactor assets from its San Mateo headquarters and Texas demo-plant. The company, which developed technology to convert waste methane from farms and landfills into organic fertilizer, had raised $37 million from investors.
Founded in 2022 by Josh Silverman, Carla Risso, Ph.D, and Louis Stenmark, Windfall Bio secured a $9 million seed round in 2023 and a $28 million Series A in 2024. Key backers included Prelude Ventures and Amazon’s Climate Pledge Fund.
The shutdown follows the termination of a significant Department of Energy grant, awarded in December 2024 for methane bioconversion as a flare replacement. This project appeared on a list of 321 terminated awards in October 2025, significantly impacting the company's prospects.
Windfall Bio's technology transformed methane into nitrogen-rich biomass for organic fertilizer, suitable for dairy farms or market sale. The company had begun constructing its demo plant last fall to showcase its innovative solution for waste gas sources.