An old steel mill is getting a new lease on life in Pueblo, Colorado. The company will be the first in the world to get the majority of its energy from solar power.

The EVRAZ Rocky Mountain Steel factory is opening a new chapter in its history. On Wednesday, a partnership called Lightsource BP—yes, that BP—unveiled the Bighorn Solar project, a new 300-megawatt solar farm. Most of the project’s 750,000 solar panels lie on the EVRAZ property itself, making the farm the largest on-site solar project in the nation dedicated to a single customer. The project was first announced in 2019 and is already partially operational. The companies say it will be fully online by next month.

Solar-powered steel is great. The iron and steel sector is responsible for 2.8 gigatons of carbon dioxide emissions every year,