San Francisco Mayor London N. Breed announced a plan to transition private commercial buildings of 500,000 square feet and larger to 100 percent renewable electricity by 2022. Then, starting in 2024, commercial buildings exceeding 250,000 square feet will be subject to the requirement, followed by commercial buildings exceeding 50,000 square feet by 2030. The phased approach is intended to ensure adequate renewable electricity is available for procurement.

The new clean electricity requirement is the first in the nation. Already, San Francisco has reduced its greenhouse gas emissions 36% below 1990 levels.