The history of Entegrus dates back nearly 100 years, when the Hydro-Electric bylaw was passed on October 15th, 1914. At that time, the newly formed Chatham Hydro took to the task of preparing Chatham's electric distribution system. Despite the enormity of this task, electricity was available three short months later, on January 15th 1915.
Hydro was not officially "turned on" until July 7th 1915, when Sir Adam Beck (the first Chairman of the Hydro Electric Commission) presided over a large civic banquet at the Chatham Armoury. Sir Adam pressed the "magic button" signifying the energization of Chatham's new electric system, distributing electricity generated by Ontario Hydro. The demonstration lit up a nitrogen filled lamp of about 1,250 candlepower at the corner of King & Fifth Streets.
The company continued to grow, and began selling electric appliances from the 'Hydro Shop' as they came onto the market. For a time, the sales department also sold small appliances door-to-door. In the 1930's, Chatham Hydro established the Parts and Small Appliances Repair Department.
Chatham Hydro, along with many other Southwestern Ontario utilities, began with 25 cycle power. During the 1950's, the former Ontario Hydro undertook a massive conversion to 60 cycles. This monumental overhaul to Chatham's station and distribution equipment culminated with most industries and businesses being converted by 1951, and all residential customers were converted by 1956.
During the 1970's, the industry focus shifted to electricity demand planning, and the Darlington nuclear generating station was opened. Chatham Hydro's biggest customers were: International, Eaton Yale & Motor Wheel.
In the late 1990's, just as plans were starting to be presented for the deregulation of the Ontario electricity supply, municipal amalgamation began to occur. Subsequently, in 1998, the Municipality of Chatham-Kent was created, amalgamating 23 separate Kent County communities. Chatham Hydro became part of the Chatham-Kent Public Utilities Commission from 1998-2000, which was comprised of ten former electric utilities and two water commissions from the following communities: Chatham, Wallaceburg, Dresden, Tilbury, Merlin, Ridgetown, Thamesville, Blenheim, Bothwell, Wheatley and the community of Erieau.
Chatham-Kent Energy was incorporated in September of 2000, as the parent company for Chatham-Kent Hydro and its unregulated affiliate, Chatham-Kent Utility Services Inc.
After significant delays, Ontario's market opening occurred on May 1, 2002, causing water commissions and electric utilities to separate. In the same year, the electricity market officially opened, and consumers could voluntary enter into retail contracts.
On June 30, 2005, Chatham-Kent Energy acquired Middlesex Power Distribution Corporation, located in Strathroy, who also served the communities of Parkhill and Mount Brydges. Middlesex Power undoubtedly became an important part of the Chatham-Kent Energy group of companies. The organization continued to grow in the Middlesex area, when Middlesex Power Distribution Corporation acquired Dutton Hydro and Newbury Power on April 30, 2009, further expanding the number of communities served by Middlesex Power.
In 2010, a new regulated transmission affiliate was incorporated - Chatham-Kent Transmission. This affiliate received approval for an electrical transmission licence in 2011 with the objective of supporting renewable energy generation.
Entegrus Powerlines was born on March 1st 2012, after the merger of Chatham-Kent Hydro and Middlesex Power Distribution Corporation on January 1st, 2012. Entegrus Inc. is the re-branded holding company for Entegrus Powerlines, Entegrus Services and Entegrus Transmission.