Châteauguay HVDC-back-to-back station is the largest high-voltage direct current

High-voltage direct current

A high-voltage, direct current electric power transmission system uses direct current for the bulk transmission of electrical power, in contrast with the more common alternating current systems. For long-distance transmission, HVDC systems may be less expensive and suffer lower electrical losses...

 (HVDC) back-to-back converter station in North America

North America

North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

. Situated near Châteauguay, on the South Shore

South Shore (Montreal)

The South Shore is the general term for the suburbs of Montreal, Quebec located on the southern shore of the Saint Lawrence River opposite the Island of Montreal. The South Shore is located within the Quebec administrative region of Montérégie....

 of Montreal

Montreal

Montreal is a city in Canada. It is the largest city in the province of Quebec, the second-largest city in Canada and the seventh largest in North America...

, Quebec

Quebec

Quebec or is a province in east-central Canada. It is the only Canadian province with a predominantly French-speaking population and the only one whose sole official language is French at the provincial level....

, it is an important plant for power exchange between Hydro-Québec

Hydro-Québec

Hydro-Québec is a government-owned public utility established in 1944 by the Government of Quebec. Based in Montreal, the company is in charge of the generation, transmission and distribution of electricity across Quebec....

 and New York Power Authority

New York Power Authority

The New York Power Authority , officially the Power Authority of the State of New York , is a New York State public benefit corporation and the largest state-owned power organization in the United States. NYPA provides some of the lowest-cost electricity in New York State, operating 17 generating...

 (NYPA).

Capacity

The station, which was built by BBC

Brown, Boveri & Cie

Brown, Boveri & Cie was a Swiss group of electrical engineering companies.It was founded in Baden, Switzerland, in 1891 by Charles Eugene Lancelot Brown and Walter Boveri who worked at the Maschinenfabrik Oerlikon. In 1970 BBC took over the Maschinenfabrik Oerlikon...

 and Siemens

Siemens

Siemens may refer toSiemens, a German family name carried by generations of telecommunications industrialists, including:* Werner von Siemens , inventor, founder of Siemens AG...

 in 1983/84, can transfer a maximum power of 1000 megawatts (MW) at a direct current

Direct current

Direct current is the unidirectional flow of electric charge. Direct current is produced by such sources as batteries, thermocouples, solar cells, and commutator-type electric machines of the dynamo type. Direct current may flow in a conductor such as a wire, but can also flow through...

 (DC) voltage

Voltage

Voltage, otherwise known as electrical potential difference or electric tension is the difference in electric potential between two points — or the difference in electric potential energy per unit charge between two points...

 of 140 kilovolts (kV). The facility, which consists of two 500 MW units is fed from Hydro-Quebec with a 315 kV line and from NYPA with a 120 kV line.

In 2009 its control system is planned to be modernized.