The development of the electricity industry in New Brunswick started the 1880s with the establishment of small private power plants in Saint John, Fredericton and Moncton.

Over the next 30 years, other cities successively electrified, so much so that in 1918, more than 20 companies were active in the electricity business, which left the province with wildly differing levels of services and prices.

Immediately, the commission, headed by its first president, C. W. Robinson, launched the construction of a C$2 million hydroelectric dam at Musquash, west of Saint John.

To supply the cities of Saint John, Moncton and Sussex, a 88 miles (142 km) long high voltage power line was also built.

The building of a larger facility in Grand Falls, on the Upper Saint John River, was undertaken in 1926 by a subsidiary of International Paper Company and completed in 1930.

The New Brunswick Electric Power Commission bought the Grand Falls Generating Station in 1959[11] and began work on the province's largest hydroelectric facility, the Mactaquac dam, whose first three units were put on stream in 1968.

To cope with this demand growth, the commission began construction of the oil-fired Courtenay Bay Generating Station, near the Saint John shipyard in 1959; it was also adjacent to the Irving Oil Refinery, which entered service in the late 1950s and which the Courtenay Bay Generating Station made use of a pipeline running from the Canaport offshore loading facility at Red Head to the refinery.

[12] To better serve northern New Brunswick, another oil-fired plant, the Dalhousie Generating Station, was constructed in Darlington with an initial capacity of 100 MW.

[12] In the early 1970s, the NBEPC signed a series of supply contracts with New England distributors, justifying the construction of its largest power plant in 1972.

[13] Formal talks between the provincial and federal governments began in 1972 and discussions between representatives of Premier Richard Hatfield and Atomic Energy of Canada accelerated the following year.

On February 5, 1974, Hatfield announced his decision to build the plant, 20 miles (32 km) west of Saint John, and even raised the possibility of constructing a second one in the future.

[16] This agreement was reached after nine months of negotiations undertaken at the request of New Brunswick[17] and would have transferred most generation, transmission and distribution assets of the New Brunswick utility to a subsidiary of the Quebec-based Crown corporation, including the Point Lepreau Nuclear Generating Station and 7 hydroelectric plants, but would have excluded fossil-fuel fired plants in Dalhousie, Belledune, and Coleson Cove.

Opposition parties, Newfoundland and Labrador premier Danny Williams,[21] the union representing most NB Power employees,[22] and wind energy supporters[23] quickly condemned the agreement as detrimental to the interests of New Brunswick.

[27] On March 24, 2010, Premier Graham announced the failure of the second agreement due to Hydro-Québec's concern over unanticipated risks and costs associated with matters including dam security and water levels.

The Liberal government of Raymond Frenette published a consultation document in February 1998 to find solutions to ensure the sustainability of NB Power in the twenty-first century.

[31] Shortly after taking office in 1999, the Conservative government of Bernard Lord commissioned TD Securities to conduct an assessment of the company's viability.

The study, whose findings were published in 2009, suggested four scenarios: the status quo; a sale to a strategic buyer; privatization through a share offering; or splitting the utility into separate elements.

[citation needed] Between 2001 and 2004, the Lord government spent C$3.2 million to retain the services of CIBC World Markets and Salomon Smith Barney in order to evaluate the resale value of the Point Lepreau and Coleson Cove power plants.

The Act maintained the company's distribution, transmission, and nuclear power monopolies, but opened the door to competition in the generation business.

David D. Hay resigned as President in 2010, claiming he had never been consulted on the proposed sale of NB Power, the valuations or the strategies involved.

[39][40] The company operates interconnections with Hydro-Québec, Nova Scotia Power, Maritime Electric in Prince Edward Island and the ISO New England network in the United States.

[48] The company extracted approximately 150,000 tons of coal per year to fuel the Grand Lake Generating Station, a 57 MW power plant built in 1963.

[39]: 15 In 2019, the utility was criticized for having invested $13 million in Joi Scientific, a Florida-based company that promised to deliver hydrogen-based power from seawater with 200% efficiency.

[58] During a call with investors during the summer of 2019, Joi Scientific announced that their technology was perhaps only ~10% as efficient as previously described, meaning that their process consumes energy rather than producing it.