September 1997 – Sheri Tackett begins building the team and serving industrial natural gas customers as Ashland Energy Services
December 1999 – Acquisition of H&N Gas Marketing
April 2000 – Acquired the assets of EMS (Energy Marketing Services)
May 2000 – Expands energy management services with the signing of first electric energy management contract
October 2001 – Expands the energy management client list through the acquisition of Clinton Energy
December 2003 – The purchase of the assets of Ashland Energy Services is complete. The team officially begins doing business as Delta Energy
August 2004 – Delta is certified as a Women’s Business Enterprise (WBE)
November 2007 – Delta Energy debuts on Business First’s Best Places to Work in Central Ohio (also named to the list in 2008, ‘09, ‘10, ‘11 and ‘12)
July 2008 – Delta Green is introduced, a service devoted to sustainable energy issues and projects
July 2009 – Completed the acquisition of Compass Energy Consulting, LLC
December 2010 – Delta forms a strategic alliance with Bergen Energi (Norway) and Comerc Energia (Brazil) known as the Energy Experts Alliance, allowing us to provide energy management services globally
May 2012 – The Energy Experts Alliance announces their expansion to Australia by welcoming EnergyAdvice to the alliance.
March 2013 – Delta acquires the energy management consulting services division of Energy Advantage in Quebec and Ontario.