Energy Systems Group
Energy Systems Group is an energy service company (ESCO) founded in 1994, helping clients achieve energy efficiency, resiliency, infrastructure, and sustainability goals.
Last updated September 1, 2026
Overview
Energy Systems Group (ESG) is an energy service company (ESCO) founded in 1994. It helps public- and private-sector organizations across the U.S. achieve their energy efficiency, resiliency, infrastructure, and sustainability goals with innovative, budget-neutral solutions. The company has over 400 employees and is licensed to work in 48 states plus Washington D.C. and the U.S. Virgin Islands.
History
Energy Systems Group, LLC was formed in April 1994 as a non-regulated, wholly-owned subsidiary of Southern Indiana Gas & Electric Company (SIGECO). It became profitable within the first five months of operation. In 1996, ownership was transferred to SIGCORP, a holding company. In 1997, SIGCORP sold two thirds of ownership to Indiana Energy and Citizens Gas & Coke Utility. In 2000, SIGCORP and Indiana Energy merged, forming Vectren Corporation, and ESG was owned by Vectren Corporation and Citizens Gas & Coke Utility. In 2003, Vectren Corporation bought the remaining one third ownership.
Sources
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