Hydro-Québec's electricity transmission system

Hydro-Québec's electricity transmission system

Hydro-Québec's electricity transmission system is an expansive, international power transmission system located in Quebec, Canada with extensions into the Northeastern United States. Major expansion of the network began with the commissioning of the alternating current 735,000 volt (735 kV) power line in November 1965, as there was a need for electricity transmission over vast distances from hydroelectric power stations in northwestern Quebec and Labrador to southern Quebec.Cite web|title=IEEE Milestone: 40th Anniversary of 735 kV Transmission System|url=http://www.ewh.ieee.org/reg/7/canrev/cr52/CR52_735kv.pdf|first=Vijay K.|last=Sood|date=2005-12-13|publisher=Institute of Electrical and Electronics Engineers|accessdate=2008-01-10]

The transmission system, containing over 32,000 kilometres (20,000 mi) of power lines, is managed by Hydro-Québec TransÉnergie, a division of the crown corporation Hydro-Québec.Cite web|title=Discover Hydro-Québec TransÉnergie and its system: Our System at a Glance|url=http://www.hydroquebec.com/transenergie/en/reseau/bref.html|publisher=Hydro-Québec TransÉnergie|accessdate=2008-01-10] One unique feature of the power system is its alternating current (AC) 735 / 765 kV power lines that stretch from the population centers of Montreal and Quebec City to the distant hydroelectric dams and power stations of the James Bay Project and Churchill Falls. The 735 kV power lines serve as the main backbone of the entire transmission system, and thus much of Quebec's population is powered by a handful of 735 kV power lines.Cite web|title=Failure of Public Utilities: Risk Management and Insurance: Pages 5–7|url=http://www.munichre.com/publications/302-03810_en.pdf|date=2003|accessdate=2008-01-10|publisher=Munich Re] This contributed to the severity of the blackout that ensued after the Ice Storm of 1998. The extent and duration of this blackout has generated criticism of the transmission system, and there is controversy concerning the use of hydroelectric dams.



Quebec's power transmission history began with the inauguration of a Convert|135|km|mi|0-long, 50 kV power line running from Shawinigan to Montreal.Cite web|title=Hydro-Québec|url=http://www.thecanadianencyclopedia.com/index.cfm?PgNm=TCE&Params=A1ARTA0003931|accessdate=2008-01-21|publisher=The Canadian Encyclopedia|first=André|last=Bolduc] At that time, regional monopolies dominated the Quebec electricity market. In light of customer complaints, the Quebec government expropriated all power companies into Hydro-Québec on April 14, 1944.

Planning for Hydro-Québec's 735 kV power grid began in 1955, when engineers looked to transmit 5,000 megawatts (MW) hydroelectric power from the Manicouagan-Outardes (Manic-Outardes) dams to Montreal, a distance of Convert|600|km|mi|-2. At that time, by using the world standard 300–400 kV voltage level, this feat would have required at least 30 individual power lines. Initially, a voltage level of 500 kV was chosen to transmit electric power, but 500 kV was considered to be a small improvement over the existing voltage level of 315 kV.Cite web|title=Hydro-Québec célèbre le 40e anniversaire de la mise en service de la première ligne à 735 kV|url=http://www.hydroquebec.com/4d_includes/surveiller/PcFR2005-228.htm|publisher=Hydro-Québec|date=2005-11-29|accessdate=2008-01-20 fr]

To effectively resolve this issue, Jean-Jacques Archambault, now regarded as the pioneer of the 735 kV power line, decided on a voltage level of 735 kV, a level over twice as high as the previous 315 kV. In 1962, Hydro-Québec proceeded with the construction of the first 735 kV power line in the world. The line, stretching from the Manic-Outardes dam to the Levis substation, was brought into service on November 29, 1965 at 1:43 pm. [Cite web|title=Appendix B: Historical Chronology of Energy-Related Milestones, 1800-1994|url=http://www.eia.doe.gov/cneaf/electricity/page/electric_kid/append_b.html|accessdate=2008-01-20|first=Robert|last=Schnapp|date=2001-09-24] Cite web|title= 1962 – Hydro-Québec|url=http://www.canadianeconomy.gc.ca/english/economy/1962HydroQuebec.html|publisher=Government of Canada|accessdate=2008-01-20|date=2007-05-04] Cite web|title=Overview of Transmission Lines Above 700 kV|first=Raymond|last=Lings|coauthors=Vernon Chartier, P. Sarma Maruvada|url=http://ieeexplore.ieee.org/iel5/10730/33853/01611782.pdf|date=2005-07-15|accessdate=2008-01-22|publisher=Inaugural IEEE PES 2005 Conference and Exposition in Africa]

Over the next twenty years, from 1965 to 1985, Quebec underwent a massive expansion of its 735 kV power grid and its hydroelectric generating capacity. Hydro-Québec Équipement, another division of Hydro-Québec, and Société d’énergie de la Baie James built these transmission lines, electrical substations, and generating stations. [Cite web|title=Construction|url=http://www.hydroquebec.com/profile/hqequipement.html|publisher=Hydro-Québec Équipement|accessdate=2008-01-21] Constructing the transmission system for the La Grande Phase One, part of the James Bay Project, took 12,500 electrical pylons, 13 electrical substations, Convert|10000|km|mi|-3 of ground wire, and Convert|60000|km|mi|-4 of electrical conductor at a cost of C$3.1 billion alone.Cite web|title=The James Bay Transmission System|url=http://www.hydroquebec.com/visit/virtual_visit/reseau_transport.html|publisher=Hydro-Québec|accessdate=2008-01-11] In less than four decades, Hydro-Québec's generating capacity went from 3,000 MW in 1963 to nearly 33,000 MW in 2002, with 25,000 MW of that power sent to population centers on 735 kV power lines.

ource of the electricity

Much of the electricity generated by Hydro-Québec Generation [Cite web|title=Hydro-Québec Generation Main Page|url=http://www.hydroquebec.com/generation/index.html|publisher=Hydro-Québec Generation|accessdate=2008-01-21] comes from hydroelectric dams located far from load centres such as Montreal.Cite web|title=HQ TransÉnergie Response To Blackouts and Catastrophic Events|publisher=Hydro-Québec TransÉnergie|accessdate=2008-01-12|date=2004-10-13|url=http://www.ieee.org/portal/cms_docs_pes/pes/subpages/meetings-folder/PSCE/2004Presentations/281/Jean-Marie-HQ-PSCE-oct13rd2004v4.pdf|first=Jean-Marie |last=Gagnon] Of the 33,000 MW of electrical power generated, over 93% of that comes from hydroelectric dams and 85% of that generation capacity comes from three hydroelectric generation centers: James Bay, Manic-Outardes, and Churchill Falls.Cite web|title=Hydro-Québec's High-Voltage Interconnections|url=http://ieeexplore.ieee.org/iel1/39/3759/00138943.pdf?arnumber=138943|accessdate=2008-01-22|publisher=Hydro-Québec and IEEE Power Engineering Review|date=1992-06|first=Jacques|last=Lemay]

;James BayThe James Bay Project encompasses the La Grande project, which is located on the La Grande River and on its tributaries, such as the Eastmain River, in northwestern Quebec. The La Grande project was built in two phases; the first phase lasted twelve years from 1973 to 1985 and the second phase lasted from 1985 to present time. [Cite web|title=Geographic Location: The La Grande Complex|url=http://www.hydroquebec.com/visit/virtual_visit/index.html|publisher=Hydro-Québec|accessdate=2008-01-21] In all, the nine hydroelectric dams there produce over 16,500 MW of electric power, with the Robert-Bourassa or La Grande-2 station generating over 5,600 MW alone. [Cite web|title=Robert-Bourassa Generating Station|url=http://www.hydroquebec.com/generation/hydroelectric/la_grande/robert_bourassa/index.html|publisher=Hydro-Québec|accessdate=2008-01-21] In total, the project cost over C$20 billion to construct.Cite web|title=The La Grande Complex|url=http://www.hydroquebec.com/sebj/en/lagrande.html|publisher=Société d'énergie de la Baie James|accessdate=2008-01-21] [Cite web|title=Brisay Generating Station|url=http://www.hydroquebec.com/generation/hydroelectric/la_grande/brisay/index.html|accessdate=2008-01-21|publisher=Hydro-Québec Generation] [Cite web|title=Laforge-2 Generating Station|url=http://www.hydroquebec.com/generation/hydroelectric/la_grande/laforge_2/index.html|accessdate=2008-01-21|publisher=Hydro-Québec Generation] [Cite web|title=Laforge-1 Generating Station|url=http://www.hydroquebec.com/generation/hydroelectric/la_grande/laforge_1/index.html|accessdate=2008-01-21|publisher=Hydro-Québec Generation] [Cite web|title=La Grande-4 Generating Station|url=http://www.hydroquebec.com/generation/hydroelectric/la_grande/la_grande_4/index.html|accessdate=2008-01-21|publisher=Hydro-Québec Generation] [Cite web|title=La Grande-3 Generating Station|url=http://www.hydroquebec.com/generation/hydroelectric/la_grande/la_grande_3/index.html|accessdate=2008-01-21|publisher=Hydro-Québec Generation] [Cite web|title=La Grande-2-A Generating Station|url=http://www.hydroquebec.com/generation/hydroelectric/la_grande/la_grande_2_a/index.html|accessdate=2008-01-21|publisher=Hydro-Québec Generation] [Cite web|title=Robert-Bourassa Generating Station|url=http://www.hydroquebec.com/generation/hydroelectric/la_grande/robert_bourassa/index.html|accessdate=2008-01-21|publisher=Hydro-Québec Generation] [Cite web|title=La Grande-1 Generating Station|url=http://www.hydroquebec.com/generation/hydroelectric/la_grande/la_grande_1/index.html|accessdate=2008-01-21|publisher=Hydro-Québec Generation] [Cite web|title=Eastmain-1 Hydroelectric Development: Read a Summary|url=http://hydroquebec.com/eastmain1/en/batir/resume.html|accessdate=2008-01-21|publisher=Hydro-Québec]

;Manic-Outardes power stationsThe Manic-Outardes river area in the Côte-Nord or North Shore region consists of several hydroelectric facilities located on three principal rivers, from west to east: Rivière Bersimis, Rivière aux Outardes, and the Manicouagan River. A single plant named Sainte-Marguerite-3 is located to the east on the Rivière Sainte-Marguerite. [Cite web|title=Discover our Hydroelectric Facilities|url=http://www.hydroquebec.com/generation/hydroelectric/index.html|publisher=Hydro-Québec Production|accessdate=2008-01-21] The facilities located in the region were constructed over a period of five decades, from 1956 to 2005. The total generation capacity from these power stations is 10,500 MW. A small generation plant located on the Rivière Ha! Ha! is not connected to the Quebec grid. [Cite web|title=Bersimis-1 Generating Station|url=http://www.hydroquebec.com/generation/hydroelectric/bersimis/bersimis_1/index.html|accessdate=2008-01-21|publisher=Hydro-Québec Generation] [Cite web|title=Bersimis-2 Generating Station|url=http://www.hydroquebec.com/generation/hydroelectric/bersimis/bersimis_2/index.html|accessdate=2008-01-21|publisher=Hydro-Québec Generation] [Cite web|title=Outardes-4 Generating Station|url=http://www.hydroquebec.com/generation/hydroelectric/outardes/outardes_4/index.html|accessdate=2008-01-21|publisher=Hydro-Québec Generation] [Cite web|title=Outardes-3 Generating Station|url=http://www.hydroquebec.com/generation/hydroelectric/outardes/outardes_3/index.html|accessdate=2008-01-21|publisher=Hydro-Québec Generation] [Cite web|title=Outardes-2 Generating Station|url=http://www.hydroquebec.com/generation/hydroelectric/outardes/outardes_2/index.html|accessdate=2008-01-21|publisher=Hydro-Québec Generation] [Cite web|title=Hart-Jaune Generating Station|url=http://www.hydroquebec.com/generation/hydroelectric/manicouagan/jaune/index.html|accessdate=2008-01-21|publisher=Hydro-Québec Generation] [Cite web|title=Manic-5-PA Generating Station|url=http://www.hydroquebec.com/generation/hydroelectric/manicouagan/manic_5pa/index.html|accessdate=2008-01-21|publisher=Hydro-Québec Generation] [Cite web|title=Manic-5 Generating Station|url=http://www.hydroquebec.com/generation/hydroelectric/manicouagan/manic_5/index.html|accessdate=2008-01-21|publisher=Hydro-Québec Generation] [Cite web|title=Manic-3 Generating Station|url=http://www.hydroquebec.com/generation/hydroelectric/manicouagan/manic_3/index.html|accessdate=2008-01-21|publisher=Hydro-Québec Generation] [Cite web|title=Manic-2 Generating Station|url=http://www.hydroquebec.com/generation/hydroelectric/manicouagan/manic_2/index.html|accessdate=2008-01-21|publisher=Hydro-Québec Generation] [Cite web|title=Manic-1 Generating Station|url=http://www.hydroquebec.com/generation/hydroelectric/manicouagan/manic_1/index.html|accessdate=2008-01-21|publisher=Hydro-Québec Generation] [Cite web|title=Illustrating Sustainable Development through Concrete Examples: Toulnustouc Hydroelectric Project|url=http://www.hydroquebec.com/sustainable-development/exemple/toulnustouc.html|accessdate=2008-01-21|publisher=Hydro-Québec] [Cite web|title=Sainte-Marguerite-3 Generating Station|url=http://www.hydroquebec.com/generation/hydroelectric/sainte_marguerite/sm3/index.html|accessdate=2008-01-21|publisher=Hydro-Québec Generation] [Cite web|title= Lac-Robertson Generating Station|url=http://www.hydroquebec.com/generation/hydroelectric/ha_ha/robertson/index.html|accessdate=2008-01-21|publisher=Hydro-Québec Generation]

;Churchill FallsChurchill Falls is a single underground generation station located on the Churchill River near the town of Churchill Falls and the Smallwood Reservoir in Labrador. It was constructed over a period of five to six years from 1966 to 1971–72 by the Churchill Falls (Labrador) Corporation, though generators were installed after major construction was completed. The single generation facility cost C$946 million to construct and produced 5,225 MW of power initially after all eleven generating units were installed.Cite web|title=Detailed Technical Specifications|url=http://ieee.ca/millennium/churchill/cf_engineering.html|first=Peter|last=Green|publisher=Churchill Falls (Labrador) Corporation and Institute of Electrical and Electronics Engineers|accessdate=2008-01-21] A station upgrade in 1985 raised the generating capacity to over 5,400 MW. The station is not owned by Hydro-Québec Generation, but instead by the Churchill Falls (Labrador) Corporation, which is the same company that constructed the generating plant. However, Hydro-Québec has rights to most of the 5,400 MW of power the station produces. [Cite web|title=Churchill Falls Generating Station|url=http://www.hydroquebec.com/generation/hydroelectric/churchill/churchill_falls/index.html|publisher=Hydro-Québec|accessdate=2008-01-21]

Electricity transmission system features

Hydro-Québec TransÉnergie's operates the largest power grid in North America, with nearly Convert|33000|km|mi|-3 of power transmission lines. The system is also unlike any other, with electrical transmission lines reaching to power generation facilities located more than Convert|1000|km|mi|-2 away from population centers.<Cite web|title=Electric-Power Transmission|url=http://www.thecanadianencyclopedia.com/index.cfm?PgNm=TCE&Params=A1ARTA0002566|publisher=The Canadian Encyclopedia|accessdate=2008-01-12|first=M.M.C.|last=Collins] Cite web|title=Power Transmission over Long Distances|url=http://www.hydroquebec.com/learning/transport/grandes_distances/index.html|accessdate=2008-01-20|publisher=Hydro-Québec] For this reason, TransÉnergie uses a voltage of AC 735 kV to transmit and distribute electrical power produced from Hydro-Québec's dams, although 315 kV is used as well.Cite web|title=Eastmain 1-A Powerhouse and Rupert Diversion: Area Development|url=http://www.ceaa.gc.ca/010/0001/0001/0017/Figure8-1_e.pdf|accessdate=2008-01-11|author=Hydro-Québec Production|date=2006-10] The total value of TransÉnergie's entire electricity transmission system is C$15.9 billion. For these reasons, Hydro-Québec TransÉnergie is considered to be a world leader in power transmission.

AC 735 / 765 kV power lines

From 1965 onwards, the 735 kV power line became an inaugural part of Québec's power transmission grid. More than one-third of Hydro-Québec TransÉnergie's system consists of ultra high voltage AC 735 / 765 kV power lines, totaling Convert|11422|km|mi|0ref label|note01|A|^ strung between 38 substations with equipment of that voltage.

The physical size of the Hydro-Québec's 735 kV transmission lines is unmatched in North America. Only two other utility companies in the same region, the New York Power Authority (NYPA) and the American Electric Power (AEP) contain at least one 765 kV line in their power system. [cite journal|last=Hammad|first=A. E.|date=1992-01|title=ANALYSIS OF SECOND HARMONIC INSTABILITY FOR THE CHATEAUGUAY HVDC/SVC SCHEME|journal=Transactions on Power Delivery|volume=7|issue=1|pages=411|url=http://ieeexplore.ieee.org/iel3/61/3308/00108935.pdf|accessdate= 2008-01-23|publisher=IEEE and ABB Power Systems] [cite journal|last=HOROWITZ|first=STANLEY H.|coauthors=HAROLD T. SEELEY|date=1969-09|title=Relaying the AEP 765-kV System|journal=IEEE TRANSACTIONS ON POWER APPARATUS AND SYSTEMS|volume=PAS-88|issue=9|pages=1382–1389|url=http://ieeexplore.ieee.org/iel5/10669/4073982/04073993.pdf|accessdate=2008-01-23|publisher=IEEE|doi=10.1109/TPAS.1969.292530] [Cite web|title=Executive Speeches|url=http://www.nypa.gov/press/speeches/2006/60823a.htm|publisher=New York Power Authority|first=Thomas J.|last=Kelly|accessdate=2008-01-11|date=2006-08-23] Cite web|title=Transmission Questions & Answers: How does the electrical system work?|url=http://www.aep.com/about/transmission/transmissionqa.htm|accessdate=2008-01-11|publisher=American Electric Power] However, only AEP has a significant mileage of 765 kV power lines, with over convert|3400|km|mi of 765 kV line traversing its broad transmission system; this system contains the most mileage in the United States under one electrical company. NYPA has only convert|219|km|mi of 765 kV line, all of it contained in a single direct interconnection with Hydro-Québec.Cite web|title=Massena Marcy 765 kV Line|url=http://www.vanderweil.com/pu_td/pu_proj_massena.asp|publisher=Vanderweil Engineers|accessdate=2008-01-11]

The 735 kV power line is said to lessen the environmental impact of power lines, as one single power line operating at this voltage carries the same amount of electric power as four 315 kV power lines, which would require a right-of-way wider than the Convert|80.0|m|ft|1Convert|91.5|m|ft|1 width required for a single 735 kV line.Cite web|title=The Development of 735-kV Transmission and Standardization at Hydro-Québec|url=http://www.scc.ca/en/news_events/features/featuresindex_26.shtml|publisher=Standards Council of Canada|accessdate=2008-01-11|date=2007-10-16] Each 735 kV line is capable of transmitting 2,000 MW of electric power at a distance of over 1,000 kilometres (600 mi) and the entire 735 kV grid can carry 25,000 MW of power. Power transmission losses over the 735 kV grid range from 4.5 to 8%, varying due to temperature and operating situations. [Cite web|title=Radisson Substation|url=http://www.hydroquebec.com/visit/virtual_visit/poste_radisson.html|accessdate=2008-01-21|publisher=Hydro-Québec] The "Ordre des ingénieurs du Québec" named the 735 kV power line system as the technological innovation of the 20th century for Quebec.


Hydro-Québec TransÉnergie's 735 kV system consists of a set of six lines running from James Bay to Montreal and a set of four lines from Churchill Falls and the Manic-Outardes power stations to Quebec City. The South Shore region of Montreal and the Saint Lawrence River between Montreal and Quebec City contain 735 kV power line loops or rings.Cite web|title=Map of the Transmission System|url=http://www.hydroquebec.com/transenergie/en/reseau/pdf/carte_reseau.pdf|publisher=Hydro-Québec|accessdate=2008-01-11] Google Earth images.]

;James BayThe James Bay hydroelectric dam complex contains several relatively short 735 kV power lines that send electricity to three principal substations, ordered from west to east: Radisson, Chissibi, and Lemoyne. [Cite web|title=James Bay|url=http://www.purplelizard.com/james%20bay.htm|publisher=Purple Lizard Maps|accessdate=2008-01-11] From these substations, six 735 kV power lines traverse the vast expanses of taiga and boreal forest in clear-cut stretches of land; this shows up clearly in aerial photos.Cite web|title=James Bay 4|url=http://www.purplelizard.com/james%20bay4.htm|publisher=Purple Lizard Maps|accessdate=2008-01-11] [Cite web|title=Vegetation Control: Overview|url=http://www.hydroquebec.com/vegetation/en/maitriser/en_bref.html|publisher=Hydro-Québec|accessdate=2008-01-11] The terrain that the power lines cross is for the most part not mountainous, but smooth and replete with lakes. Generally, four of the lines runs together in two pairs and the other two run solo, although the two single lines sometimes do run in a pair. Two intermediate 735 kV power lines, one in the north and one in the south, connect all six power lines along their path to southern Quebec.

As the lines continue south, they diverge into two sets of three 735 kV transmission lines. The eastern set heads to Quebec City, where it connects with power lines from Churchill Falls and the 735 kV power line loops in the Saint Lawrence River region. The western set heads to Montreal, where it too forms a ring of 735 kV power lines around the city, linking to other power loops in the region. This section of Hydro-Québec TransÉnergie's power grid contains Convert|7400|km|mi|-2|abbr=on of AC 735 kV and DC ±450 kV power line.

;Manic-Outardes power stations / Churchill FallsElectrical power generated from the Churchill Falls power station is sent to Montreal and the population centers of the Northeastern United States, more than Convert|1200|km|mi|-2 away. [Cite web|title=Churchill Falls – Power from of the Project|accessdate=2008-01-11|publisher=A Scoff an' Scuff's|url=http://www.ascoffanscuff.com/lab/cf/cf06.html] Starting from the generation station in Labrador, the power lines span a distance of Convert|1800|m|ft|-3 over the Churchill River gorge and run generally south-southwest for Convert|203|km|mi|0 as three side-by-side power lines in a cleared right-of-way with a width of 216 metres (710 ft).Cite web|title=The History of Churchill Falls: A Brief History|url=http://www.ewh.ieee.org/reg/7/millennium/churchill/cf_history.html|accessdate=2008-01-11| publisher=Churchill Falls (Labrador) Corpororation and Institute of Electrical and Electronics Engineers|first=Peter|last=Green] As they head southwest through boreal forest, the lines generally traverse flat, smooth rolling hills.

After the lines cross the Quebec-Labrador border, also known as the Hydro-Québec point of delivery, the direction of the lines becomes due south, and they head into a substation adjacent to the Poste Montagnais (Mile 134) Airport. A lone 735 kV line stems off from the substation, heading to an open pit mine far to the northwest. The terrain crossed by the power lines becomes hilly and mountainous south of the border. The lines reach over Convert|800|m|ft|-2 in elevation before descending.Google Earth elevations.] The three lines continue heading south until they reach a substation on the North Shore of the Gulf of Saint Lawrence. From there on, the three lines parallel the North Shore as the Gulf narrows to the southwest toward the Saint Lawrence River discharge mouth. The northernmost power line then diverges from the other two to connect with Manic-Outardes power stations located on and around the Rivière aux Outardes and the Manicouagan River.

As the lines near Quebec City, the northern power line rejoins the other two 735 kV power lines. The three lines, paralleled by another 735 kV power line some distance to the north, span over the Saint Lawrence River to the South Shore region, where the lines form loops encompassing part of the Saint Lawrence River and the south shore. The loops are also connected to the ring of 735 kV power lines around Montreal and power lines running south from James Bay.

Electricity pylons

Quebec's transmission system contains a variety of electrical pylons depending on era and voltage level. Older pylon designs tend to consume more material than the newer pylons and the higher the voltage level, the larger the tower.

;735 kV pylonsHydro-Québec TransÉnergie uses several different types of electricity pylons to support their 735 kV power lines. All of them are single-circuit, meaning that each pylon carries one power line with three bundles of four electrical subconductors separated by spacers, with each bundle transmitting one phase of current.

The earliest type of tower used was a massive self-supporting delta pylon, or waist pylon,Cite web|title=Types of Towers|url=http://www.hydroquebec.com/learning/transport/types_pylones/index.html|publisher=Hydro-Québec|accessdate=2008-01-20] which consumed 21 tonnes of steel per kilometre of line. This type of pylon was used for the first 735 kV power line from the Manic-Outardes power stations to the load centre of Montreal. There are two significant variations of the delta pylon; one has longer side crossbars such that all three bundles of conductors are suspended on V-shaped insulators.Cite web|title=Transmission Towers in Winter|url=http://pro.corbis.com/popup/Enlargement.aspx?mediauids={ced9594f-da50-4722-a7d3-c1d7c6359960}|{ffffffff-ffff-ffff-ffff-ffffffffffff}&qsPageNo=1&fdid=&Area=Search&TotalCount=34&CurrentPos=9&WinID={ced9594f-da50-4722-a7d3-c1d7c6359960}|publisher=Corbis.com|accessdate=2008-01-11|first=Perry| last=Mastrovito|date=2001] The other has shorter side crossbars, such that the two outside bundles are hung on a vertical insulator string and only the middle bundle is hung with a V-shaped insulator. [Cite web|title=Transmission Towers for Hydroelectric Power Lines|url=http://pro.corbis.com/popup/Enlargement.aspx?mediauids={b0956297-ea50-4ea2-8a59-707781fe372f}|{ffffffff-ffff-ffff-ffff-ffffffffffff}&qsPageNo=1&fdid=&Area=Search&TotalCount=34&CurrentPos=25&WinID={b0956297-ea50-4ea2-8a59-707781fe372f}|publisher=Corbis.com|accessdate=2008-01-11|first=Roger |last=Ressmeyer|date=1990-10-29]

Over the years, Hydro-Québec researchers engineered a new type of pylon, the V-guyed tower, which reduced materials consumption to 11.8 tonnes of steel per kilometre of power line. This type of tower also includes a variation with longer side crossbars, where all conductors are hung with a V-shaped insulator [Cite web|title=Transmission Lines|url=http://www.ourlabrador.ca/viewphoto.php?id=118|publisher=Our Labrador|accessdate=2008-01-11] and one with shorter side crossbar, where only the middle bundle hangs from the insulator and the side bundles are strung on vertical insulator strings. [Cite web|title=Day 3: Radisson & Chisasibi|url=http://www.purplelizard.com/james%20bay2.htm|publisher=Purple Lizard Maps|accessdate=2008-01-19] [Cite web|title=Houses Covered in Snow|url=http://pro.corbis.com/popup/Enlargement.aspx?mediauids={1378524a-05e8-4a3b-8328-ff7887d2b77a}|{ffffffff-ffff-ffff-ffff-ffffffffffff}&qsPageNo=1&fdid=&Area=Search&TotalCount=34&CurrentPos=20&WinID={1378524a-05e8-4a3b-8328-ff7887d2b77a}|publisher=Corbis.com|accessdate=2008-01-11|first=Perry|last=Mastrovito|date=2001]

During the construction of the James Bay transmission system, the cross-rope suspension tower was invented. This type of tower features two guyed-tower legs similar to the V-guyed tower, but the two legs don't converge at the tower base. In the case of the cross-rope suspension tower, the tower legs are spread apart on two different foundations. In addition, the crossbar is replaced by a series of suspension cables with three vertical insulator strings to support the three bundles, which allows this design to consume only 6.3 tonnes of steel per kilometre of line. The design is also known as the Chainette (little necklace). [Cite web|title=Unique Suspension System Conquers Rugged Terrain|url=http://tdworld.com/mag/power_unique_suspension_system/|publisher=Transmission&Distribution World|date=1997-08-01|first=H. Brian|last=White|accessdate=2008-01-11]

TransÉnergie uses two-level pylons for angle towers or structures on 735 kV power lines to change the direction of the line or switch the position of the conductor bundles. Delta pylons and three-leg guyed towers are also used as angle towers; they are referred to as "penguins" by Hydro-Québec linemen. [Cite web|title=Transmission Tower|url=http://pro.corbis.com/popup/Enlargement.aspx?mediauids={a7d01d32-bb18-4c43-8982-42ba3bb04099}|{ffffffff-ffff-ffff-ffff-ffffffffffff}&qsPageNo=1&fdid=&Area=Search&TotalCount=34&CurrentPos=32&WinID={a7d01d32-bb18-4c43-8982-42ba3bb04099}|publisher=Corbis.com|accessdate=2008-01-12|first=Perry|last=Mastrovito]

;Pylons for other voltage levelsHydro-Québec TransÉnergie uses a combination of double-circuit three-level pylons and single-circuit delta pylons to suspend electrical conductors of other voltages, such as 315 kV. [Cite web|title=Central Labrador:Virtual Tour Quebec Hwy 389 – Baie Comeau to Labrador City|url=http://tlhwy.com/central/virtualtour/hwy389/hwy38901.html|accessdate=2008-01-11] The ±450 kV high-voltage direct current line in Hydro-Québec's power grid uses a T-shaped tower, lattice or pole, to support two bundles of three conductors on each side. The direct current power line sometimes uses two poles or a wider, pyramidal, self-supporting lattice structure for angle towers. [Cite web|title=Photography featuring beautiful bridges, scenic highways and railroads.|url=http://massroads.com/gallery.php?go=go&word=450kv|publisher=Massroads.com|accessdate=2008-01-12]

;Other plyonsHydro-Québec usually uses tall, large pylons to cross large bodies of water, like lakes and rivers. These towers are said to be prominent and the tallest pylon in Hydro-Québec's power grid is of this function. It is located near the Tracy power station on the shore of the Saint Lawrence River between Berthierville and Tracy. The pylon is convert|174.6|m|ft|1 tall, the same height as the Montreal Olympic Stadium.Cite web|title=Crossings|url=http://www.hydroquebec.com/learning/transport/types_pylones/ex_traversees.htm|publisher=Hydro-Québec|accessdate=2008-02-15 Note: Need to access this reference through the types of tower page [http://www.hydroquebec.com/learning/transport/types_pylones/index.html here] .]

;Pylon strengthThe pylons and conductors are designed to handle 45 millimetres (1.8 in) of ice accumulation without failure,Cite web|title=Glazed over: Canada copes with the ice storm of 1998|url=http://www.encyclopedia.com/doc/1G1-53709850.html|accessdate=2008-01-12|publisher=Heldref Publications|date=1999-01-01|author=Burton] since Hydro-Québec raised the standards in response to ice storms in Ottawa in December 1986 and Montreal in February 1961, which left 30 to 40 millimetres (1.2 to 1.6 in) of ice. [Cite web|title=Ice Storm 1998|url=http://www.thecanadianencyclopedia.com/index.cfm?PgNm=TCE&Params=A1ARTA0009646|first=Laura|last=Neilson|publisher=The Canadian Encyclopedia|accessdate=2008-01-12] Cite web|title=Surviving 1998's Great Ice Storm|url=http://www.canadianencyclopedia.ca/index.cfm?PgNm=TCE&Params=M1ARTM0011478|date=1998-01-26|first=Stephanie|last=Nolen|publisher=The Canadian Encyclopedia|accessdate=2008-01-12] Cite web|title=Verglas '98|url=http://www.haya.qc.ca/storm.htm|accessdate=2008-01-12|date=1998-03-29] This has led to the belief that Hydro-Québec TransÉnergie's electrical pylons are "indestructible".Cite web|title=Montreal in the Ice Storm January 1998|url=http://home.thezone.net/~sharvey/icestorm.htm|accessdate=2008-01-20|first=Stuart L.|last=Harvey|date=1998] Despite being more than three times higher than the Canadian standard of only 13 millimetres (0.5 in) of ice tolerance, [Cite web|title=The cost of redundancy|url=http://www.energyrisk.com/public/showPage.html?page=7188|publisher=energyrisk|accessdate=2008-01-12] an ice storm in the late-1990s deposited well over 45 millimetres (1.8 in) of ice.


The international transmission grid contains 18 interconnections between power grids located in adjacent provinces or states such as Ontario, New Brunswick, Newfoundland and Labrador, and New York. Several of those connections involve one or more 735 kV power lines, but most involve lines with a voltage lower than 735 kV. Another connection consists of a ±450 kV high-voltage direct current (HVDC) transmission line crossing an international border. These interconnections allow Hydro-Québec to import as much as 7,100 MW of electric power or export as much as 9,575 MW to neighboring regions. A 19th interconnection is planned between Ontario and Quebec, with an expected completion year of 2009. This new interconnection has generated some debate over the need to transmit an additional 1,250 MW of power to Ontario.Cite web|title=Ontario-Quebec power line sparks debate|url=http://www.cbc.ca/canada/story/2007/06/20/power-line.html|publisher=CBC News|accessdate=2008-01-11|date=2007-06-20]

High voltage direct current (HVDC) ±450 kV

In addition to the six 735 kV power lines that stem from the James Bay Project, a seventh power line was constructed as an Convert|1100|km|mi northward extension of an existing high-voltage direct current (HVDC) line connecting Quebec and New England. This power line expansion was completed in 1990. As a result, the direct current power line is unique because there are multiple static converter and inverter stations along the Convert|1480|km|mi|-1 long power line. It is also the first multiterminal HVDC line in the world. The ±450 kV power line can transmit about 2,000 MW of hydroelectric power to Montreal and the Northeastern United States.Cite web|title=The HVDC Transmission Quebec – New England|url=http://www.abb.com/cawp/gad02181/c1256d71001e0037c12568340029b5c4.aspx?&opendatabase&v=17ea&e=us&m=100a&|publisher=The ABB Group|accessdate=2008-01-11|date=2007-02-08] [Cite web|title=Contracts, All Requirements: Hydro-Québec Interconnection|url=http://www.mmwec.org/html/contracts.htm|publisher=Massachusetts Municipal Wholesale Electric Company|accessdate=2008-01-12] cite book|title=Power Electronics Design: A Practitioner's Guide|last=Sueker|first=Keith H.|origyear=2005|url=http://books.google.com/books?id=KuFt9Bcc9zYC&pg=PA8&lpg=PA8&dq=hydro+quebec+765+kv+transmission+mileage&source=web&ots=QOu5EsWCuj&sig=EwOhBbcsT4o59zb3AJ011OusQfY#PPA9,M1|format= |accessdate=2008-01-20|publisher=Elsevier|language=English|isbn=0750679271|pages=8–9|chapter=1]

;RouteBeginning in the converter station next to the Radisson substation, the HVDC line heads south and roughly parallels the six 735 kV power lines some distance to the west. It traverses the same type of terrain as the other six lines; the land is replete with lakes, wetlands, and forested rolling hills. Gradually, the power line turns to the southeast, as it crosses under several 735 kV power lines.

After the six 735 kV wires split up into two groups of three power lines each, the HVDC line follows the eastern group, and the western set diverges away. The line remains overhead until it reaches the north shore of the Saint Lawrence River near Grondines, where the ±450 kV HVDC line descends into an underwater tunnel traversing the river. The crossing was the world's first underwater crossing for a ±450 kV HVDC line. The power line surfaces on the south shore near Lotbinière substation. After the river crossing, the line enters into the Nicolet terminal near Montreal. South of the terminal, the line heads south and after a relatively short distance, it enters the Des Cantons close to Sherbrooke.

Leaving the Des Cantons station, the power line crosses the United States-Canada border and passes through the hilly Appalachian Mountains in the U.S. state of Vermont, reaching an elevation of about Convert|650|m|ft|-1. The line then continues heading south-southeast and enters the state of New Hampshire, where it reaches the Comerford terminal near Monroe. Continuing southward into Massachusetts, the line reaches the Sandy Pond terminal outside of Boston in Ayer. The terminal is the southernmost extent of the HVDC line.

Other features

TransÉnergie uses series compensation to alter the way electricity behaves in power transmission lines, which improves the electricity transmission efficiency. This reduces the need to construct new power lines and increases the amount of electric power sent to population centres. Series compensation is based on capacitor technology. To maintain its transmission system performance, TransÉnergie sets aside funds for research and application of new technologies.Cite web|title=Discover Hydro-Québec TransÉnergie and its system: Features of Our Transmission System|url=http://www.hydroquebec.com/transenergie/en/reseau/caracteristiques.html|publisher=Hydro-Québec TransÉnergie|accessdate=2008-01-10] In addition to power transmission technology, Hydro-Québec plans to offer high-speed internet over its transmission lines within a few years; the utility started testing internet over its lines in January 2004. [Cite web|title=Hydro-Québec to test internet over power lines|url=http://www.cbc.ca/news/story/2003/11/21/power_lines031121.html|accessdate=2008-01-12|publisher=CBC News|date=2003-11-24]

Major disruptions

In spite of the transmission system's reputation and the fact Quebec escaped unscathed from the Northeast Blackout of 2003, the system has experienced damage and service interruptions from severe storms in the past. [Cite web|title=How one power grid kept lights on: Hydro-Québec's system, too, is imperfect But its unique safeguards helped it survive blackout|url=http://www.ontariotenants.ca/electricity/articles/2003/ts-03i08.phtml|publisher="Toronto Star"|date=2003-09-08|first=M. Corey|last=Goldman|accessdate=2008-01-11] Examples include the 1982 and 1988 Quebec blackouts prior to the large 1989 and 1998 power interruptions.

1989 Geomagnetic storm

At 2:44 am on March 13, 1989, a severe geomagnetic storm, due to a coronal mass ejection from the Sun, struck Earth. [Cite web|title=Scientists probe northern lights from all angles|url=http://www.cbc.ca/health/story/2005/10/22/northern_lights_051022.html|] publisher=CBC News|date=2005-10-22|accessdate=2008-01-13] Fluctuations within the magnetic field of the storm caused Geomagnetically Induced Currents (GICs) to flow through Quebec's power lines, which are direct current, instead of the alternating current carried by the power lines.Cite web|title=Space weather: Page 1|url=http://findarticles.com/p/articles/mi_m1511/is_n8_v16/ai_17253896/pg_1|publisher=Discover|accessdate=2008-01-20|date=1995-08|first=Eric J.|last=Lerner] The insulating nature of the Canadian Shield igneous rock directed the GICs to the power lines. The conductors then forwarded this current to sensitive electrical transformers, which require a certain voltage amplitude and frequency to function properly. Although most GICs are relatively feeble, the nature of those currents destabilized the voltage of the power grid and current spikes erupted everywhere.

Accordingly, protective measures were taken in response. To save the transformers and other electrical equipment, the power grid was taken out of commission, as circuit breakers tripped all over Quebec and shut off the power. [Bolduc, 2002] Within less than 90 seconds, this wave of breaking circuits left the entire transmission grid out of service. The collapsed power grid left six million people and the rest of Quebec without electricity for hours on a very cold night. Even though the blackout lasted around nine hours for most places, some locations were in the dark for days. This geomagnetic storm caused about C$10 million in damage to Hydro-Québec and tens of millions to the customers of the utility.

1998 ice storm

From January 4/5 to January 10, 1998, warm moist air from the south overriding cold air from the north produced an ice storm, leading to over 80 hours of freezing rain and drizzle. [Cite web|title=A closer look at a rare situation: Weather Situation|url=http://www.msc-smc.ec.gc.ca/media/icestorm98/icestorm98_a_closer_look_e.cfm|accessdate=2008-01-16|publisher=Environment Canada] Cite web|title=The worse ice storm in Canadian history?|url=http://www.msc-smc.ec.gc.ca/media/icestorm98/icestorm98_the_worst_e.cfm|date=2002-12-18|accessdate=2008-01-16|publisher=Environment Canada] For days, a continuous shower of mostly freezing rain amounted to 70–110 millmetres (2.8–4.3 in) of water equivalent of precipitation.Cite web|title=Ice storm 1998: Lessons learned|url=http://www.treecanada.ca/cufc6/proceedings/papers/McCready.pdf|accessdate=2008-01-12|publisher=6th Canadian Urban Forest Conference|first=Jim|last=McCready|date=2004-10-23] Places like Montreal and the South Shore were especially hard hit, with Convert|100|mm|in|1|abbr=on of largely freezing rain falling. These heavy precipitation totals wreaked havoc on the regional power transmission system.

;Physical damageFive to six days of freezing rain and precipitation crippled the Hydro-Québec power grid in the Montreal and South Shore regions. In an area 100 by 250 kilometres (60 by 150 mi), some 116 transmission lines were out of commission, including several major 735 kV power lines and the Quebec–New England HVDC ±450 kV line.Cite web|title=DAWG Database 1998: January 1, 1998–December 31, 1998|url=http://www.nerc.com/~dawg/database/dawg-98.html#top|accessdate=2008-01-12|publisher=North American Electric Reliability Corporation] Through successive waves of freezing precipitation, more than 75 millimetres (3.0 in) of radial ice accumulated on the electrical conductors and the pylons themselves. This ice coating adds an additional weight of 15 to 20 kilograms per metre of conductor (10 to 20 lb/ft). Even though the electrical wires can withstand this extra weight, when combined with the effects of wind and precipitation, these conductors may break and fall. The pylons, designed to withstand only 45 millimetres (1.8 in) of ice accretion, buckled and collapsed into twisted heaps of mangled steel. Cascading failures occurred on several transmission lines, where the collapse of one or more towers left a row of fallen pylons. [cite journal|last=Tucker|first=Kyle|coauthors=Asim Haldar|date=2007-10-04|title=Numerical Model Validation and Sensitivity Study of a Transmission-Line Insulator Failure Using Full-Scale Test Data|journal=IEEE Transactions on Power Delivery|volume=22|issue=4|pages=2439|url=http://ieeexplore.ieee.org/iel5/61/4302501/04302561.pdf?arnumber=4302561|accessdate=2008-01-22|doi=10.1109/TPWRD.2007.899781]

Of all the pylons damaged, some 150 were pylons supporting 735 kV lines, and 200 towers carrying 315 kV, 230 kV, or 120 kV power lines collapsed as well.ref label|note01|B|a In a region bounded by Montreal between Saint-Hyacinthe, Saint-Jean-sur-Richelieuand Granby, dubbed the "triangle of darkness", half of the overhead power grid was out of service. Quebec ordered myriad conductors, crossarms, and wire connections to repair the ones disabled by the storm in the electrical transmission and distribution system. In all of Quebec, 24,000 poles, 4,000 transformers, and 1,000 electrical pylons were damaged or destroyed,ref label|note01|B|b more than Convert|3000|km|mi|-3|abbr=on of downed electrical wires; this cost a total of C$800 million to repair.Cite web|title=Ice Storm Da

;Power outageWith over 100 transmission lines paralyzed by the ice, Quebec fell into a massive power outage in the cold Canadian winter. Even though power restoration initiated after the first blackouts, large numbers of Quebecers were in the dark. At the height of the blackout, some 1.4–1.5 million homes and customers, housing three [Statistics Canada, The St. Lawrence River Valley 1998 Ice Storm: Maps and Facts (Ottawa, 1998); and Ontario Hydro, The State of the Power Transmission Network, 1998.] to more than four million people, were in the dark.Cite web|title=Chilling memories of 1998 ice storm that battered Quebec, Ontario, Maritimes|url=http://www.macleans.ca/canada/wire/article.jsp?content=n010322A|publisher=The Canadian Press|accessdate=2008-01-20|date=2008-01-03|first=Sidhartha|last=Banerjee] [Cite web|title=Recollections of 1998's Great Ice Storm still bring shivers|url=http://www.nationalpost.com/news/canada/story.html?id=216041|publisher="National Post" and CanWest News Service|accessdate=2008-01-21|date=2008-01-04|first=Meagan|last=Fitzpatrick] Private companies and other utilities from other parts of Canada and the United States were sent in to help Hydro-Québec undertake this massive restoration task, but these efforts were complicated by the widespread damage of the power grid. [Swiss Reinsurance Company Canada, Inside an Ice Storm (Toronto, 1998).] Blackouts in some areas lasted for 33 days, and 90% of those affected by the blackout had no power for more than seven days. Although power was fully restored to all locations in Quebec by February 8, 1998, it wasn't until mid-March that the power facilities were back in service. By then, much social and economic damage had occurred, such as ruined food and deaths resulting from lack of electric heating.

After the power outage was over, Hydro-Québec made numerous upgrades to its system in order to improve the power grid. Examples include the strengthening of electrical pylons and power poles, and increasing the power supply. This was done to enable the utility to restore power more rapidly in the case of a massive ice striking Quebec again. Hydro-Québec has stated that it is better-prepared to handle an ice storm with the same magnitude as the one of 1998.


The performance of Hydro-Québec TransÉnergie's power grid during 1998 Ice Storm raised questions about the fundamental concept, vulnerability, and reliability of the grid. Critics noted that the power generation facilities were located approximately Convert|1000|km|mi|abbr=on|-2 away from population centres and that there was a lack of local power stations around Montreal, which is served by only six 735 kV feeder lines. [Report on the State of the Power System, submitted to the ministre d'etat des ressources naturelles du Quebec, 21 January 1998.] In addition, the 735 kV transmission system received scorn from the public and the media. The power transmission grid was said to concentrate power transmission on only a few 735 kV lines, such as those that run from James Bay to Montreal. Out of the six 735 feeder lines in Montreal, five of them form a loop called the "ring of power" around the city. When the ring failed on January 7, 1998, roughly 60% of Greater Montreal's power supply was offline. Hydro-Québec's large above-ground transmission and distribution system was considered to be exposed to natural disasters, although the cost of undergrounding the grid was prohibitive.

The technology utilized on Hydro-Québec TransÉnergie grid also came under fire from critics. It is claimed that this technology, used to improve performance, safety, and reliability, made people in Quebec over-dependent on the power grid for their energy needs, since electricity, especially hydroelectric power, makes up over 40% of Quebec's energy supply. This dependence, evidenced by the fact Ontario farmers had more backup generators than farmers in Quebec, can increase the severity of the consequences when the grid fails, as it did in January 1998.


:A. note label|note01|A|^ Two figures are given for the length of the 735 kV system: convert|11422|km|mi|abbr=on|0 and convert|11527|km|mi|abbr=on|0.:B. ^ note label|note01|B|anote label|note01|B|b Estimates on the total number of poles and pylons damaged / destroyed by the ice storm varies.


*Cite book|title=America's Electric Utilities: Past, Present and Future|edition=5|first=Leonard S.|last=Hyman;Specific

External links

* [http://archives.cbc.ca/IDD-1-70-258/disasters_tragedies/ice_storm/ CBC TV archives of the 1998 Ice Storm]
* [http://massroads.com/gallery.php?go=go&word=450kv Pictures of the Quebec–New England line in Massachusetts and New Hampshire]
* [http://gazdemo.ygingras.net/wiki/Pylons Pictures of Quebec's pylons]

Wikimedia Foundation. 2010.

Look at other dictionaries:

  • Hydro-Québec — Type Government owned corporation Industry Electric Utilities Founded …   Wikipedia

  • Quebec - New England Transmission — The Quebec New England Transmission is a long distance HVDC line between Radisson, Quebec, and Sandy Pond in Ayer, Massachusetts. In contrast to most other HVDC facilities, it is equipped with multiple static inverter stations.Originally, the… …   Wikipedia

  • Hydro-Quebec — Hydro Québec Logo de Hydro Québec Création 14 avril 1944 Dates clés …   Wikipédia en Français

  • Hydro-québec — Logo de Hydro Québec Création 14 avril 1944 Dates clés …   Wikipédia en Français

  • Hydro Québec — Logo de Hydro Québec Création 14 avril 1944 Dates clés …   Wikipédia en Français

  • Hydro-Québec — Création 14 avril 1944 Dates clés 1963 : nationalisation de 11 compagnies d électricité ; …   Wikipédia en Français

  • Hydro One — Inc. Type Crown Corporation Industry Electricity delivery Predecessor Ontario Hydro …   Wikipedia

  • Quebec — This article is about the Canadian province. For the province s capital city, see Quebec City. For other uses, see Quebec (disambiguation). Coordinates …   Wikipedia

  • Transmission tower — A delta pylon carrying a 400kV power line towards Madrid. A transmission tower (colloquially termed an electricity pylon in the United Kingdom and parts of Europe, an ironman in Australia, and a hydro tower in parts of Canada) is a tall structure …   Wikipedia

  • Transmission électrique — Ligne à haute tension Pour les articles homonymes, voir Haute tension. Lignes à haute tension. Une ligne à haute tension est le composant principal des r …   Wikipédia en Français

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.