The Biden administration expanded its proposed solar development plan for public lands in the West on Wednesday, a step officials said is crucial to delivering on President Joe Biden’s goal of reaching a 100% emissions-free power grid by 2035.

The new proposal is an update to the Bureau of Land Management’s 2012 Western Solar Plan. That Obama-era plan identified federal acres across six Western states — Arizona, California, Colorado, Nevada, New Mexico, and Utah — that had high development potential for utility-scale solar power.