Norton Energy Storage, LLC, proposed to utilize the existing PPG limestone underground mine in the city of Norton for storing compressed air to generate electricity during peak demands. The project would be developed in phases up to 2700 MW. The application was filed on October 24, 2000. The Board approved the certificate on May 21, 2001. A 30-month extension was approved by the Board on March 20, 2006, and an additional 30-month extension was approved by the Board on June 2, 2008. On November 23, the Applicant filed notice that FirstEnergy Generation Corporation had purchased the membership interest of Norton Energy Storage, LLC, from CAES Development Company, LLC. On Sept. 30, 2013, the Board invalidated the certficate.