Automotive giant GM announced today that it has signed a 15-year renewable energy purchase agreement with NorthStar Clean Energy, a unit of CMS Energy, to fuel three GM assembly plants.

The announcement marks GM’s largest power purchase deal yet and an important milestone in the company’s goal to be carbon neutral by 2040, according to the company.

In 2022, GM announced that it had finalized the energy sourcing agreements required to secure 100% of the energy needed to power all its U.S. sites with renewable electricity by the end of 2025, five years ahead of its prior 2030 target, set only months earlier.

With the new purchase agreement in place, GM said that it now has sourcing agreements from 17 renewable energy plants across 11 states, making the company the automotive industry’s largest buyer of renewable power by capacity.

Under the new agreement, NorthStar’s 180 MW Newport Solar project in Newport, Arkansas, will add renewable energy directly to the grid that supports the electricity needs of GM’s Lansing Delta Township Assembly and Lansing Grand River Assembly in Michigan, and the Wentzville Assembly site in Missouri.