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Home > In Your Community > New Projects > Transmission System Projects
Transmission System Projects
Hydro One - Hydro-Québec TransÉnergie
Interconnection
What's New
August 29, 2007 - See more project
details and construction photos below.
Increasing Electricity Supply and Reliability for Ontario
Electricity Consumers
Hydro One Networks and Hydro-Québec TransÉnergie
have signed an agreement to proceed with the construction of a 1250 megawatt
(MW) interconnection between their respective transmission systems. The
agreement was announced on November 14, 2006 by Ontario's Minister of
Energy Dwight Duncan and Pierre Corbeil, Quebec's Minister of Natural
Resources and Wildlife. (Read
the announcement - version
française)
Hydro One's $124-million investment to upgrade its interconnection with
Quebec provides Ontario with better access to competitively priced renewable
hydro-electric energy from Quebec, and will improve reliability of supply.
Project Approvals
Hydro One obtained Ontario Environmental Assessment Act approval
in 2000 when the transmission upgrade for an improved interconnection
with Hydro-Québec were first studied. Hydro One's proposed undertaking
is documented in the Hydro One Networks Inc. - Hydro-Québec Environmental
Study Report, 230 kV Interconnection Environmental Study Report, May 2000.
Download the May 2000 ESR and Appendices below:
Hydro One subsequently received Ontario
Energy Board "Leave to Construct" approval in January 2001.
This approval was updated in March 2004 to extend the expiry date of the
leave to construct approval to December 31, 2006. (View
OEB Decision & Order dated March 30, 2004)
Project Details and Construction Schedule
Hydro One will begin construction at the end of November 2006
and expects to have the project completed by the end of 2008.
The project involves:
- Replacing the existing 115 kilovolt (kV) and 230 kV single-circuit
transmission lines on a existing transmission corridor between Hawthorne
Transformer Station (TS) and the Ottawa River, a distance of approximately
20 kilometres, with two double-circuit 230 kV transmission lines.
- Upgrading and reconfiguring existing facilities on Hydro One property
at Hawthorne TS, and at points along the line, including Gamble Junction,
Wilhaven Junction, Cumberland Junction and Borromee Junction.
The map below shows the section of the existing transmission corridor
to be upgraded.
Public Notification of Start of Construction
Following the Minister of Energy's announcement, Hydro One
notified City of Ottawa officials, local MPPs and property owners along
the transmission corridor about its intent to proceed with this project.
In addition, a Public Information Centre (PIC) was held to allow members
of Hydro One's project team to review project details and the construction
schedule with local residents.
Public Information Centre
Thursday, November 23, 2006
5:00 p.m. to 9:00 p.m.
Navan Memorial Community Centre
1295 Colonial Road, Navan
Download notification
delivered to property owners along the transmission corridor (version
française)
Download
PIC newspaper advertisement
(version française)
Download
PIC display panels
(PDF 1.4 MB)
More Project Details
The project involves building two new 230 kilovolt (kV) transmission
lines between Hawthorne Transformer Station (TS), in Ottawa and The Hydro
Québec electrical transmission system using existing rights of
way so that no new property will have to be acquired and construction
disruption can be kept to a minimum.
Hydro One presently operates two transmission lines that run between
Hawthorne TS and the Ottawa River crossing near Masson, Québec.
Each of these transmission lines occupies a separate right-of-way. The
northern line is a single-circuit 115 kV line (H9A). The southern line
is single-circuit 230 kV line (D5A).
This project will remove both lines and replace them with two new lines
using taller double circuit towers. The northern double-circuit line will
carry both the H9A and D5A circuits. The southern double-circuit line
will carry two new 230 kV lines that will increase our ability to import
and export power in and out of Québec by 1250 megawatts (MW).
The advantage of this plan is that it greatly increases the reliability
and security of Ontario's electricity system while causing virtually no
permanent changes in the current land use. It will do this by replacing
the existing towers on a tower-by-tower basis. Where there is a tower
now, there will be a new larger tower when the job is complete. The only
inconvenience and disruption will take place during the relatively short
construction period.
The only exception to the tower-by-tower approach will be in the four
kilometre section of the line that runs between Tenth Line and Cardinal
Creek where steel-pole towers rather than the more common lattice towers
will be used. The length of the spans between steel-pole towers is less
than what is possible between lattice towers. Thus, additional steel-pole
towers will be necessary in this section of the line.
When the project is complete at the end of 2008, the new northern double-circuit
tower line will carry the same amount of electricity as the present H9A
and D5A. H9A will continue to operate at 115 kV and D5A at 230 kV. However,
the new H9A circuit will have insulators that will allow it to be operated
at 230 kV as well. This will allow H9A to be upgraded to 230 kV operation
when extra transmission capacity is needed in the future. This future
increase in capacity will not require additional line construction or
disruption.
The new southern double-circuit line will provide new capacity to import
electricity from Québec and export electricity to Québec.
It represents the Ontario half of a major agreement between Hydro One
and TransÉnergie (Hydro Québec's transmission subsidiary).
On the Québec side of the border, TransÉnergie is building
a similar transmission line and a back-to-back AC/DC/AC converter that
will allow Hydro One to easily import power from or export power to Québec.
Construction Activities
The existing corridor is wide enough to accommodate the new lines and
no new property rights will have to be acquired. However, every tower
in both existing lines must be replaced with a newly designed larger tower
which will also require a larger re-engineered foundation. Thus, the sequence
of construction activities will be:
Brush clearing: Where necessary, crews remove accumulated brush
from the tower sites and access roads so that construction can begin.
Access road construction: Temporary access roads have been constructed
by laying down heavy-duty cloth called geotextile and covering it with
crushed limestone. The temporary roads will be built to allow all heavy
equipment to be used to mitigate permanent damage to the environment.
The geotextile will prevent the rock from merging with the top soil
and will allow the roads to be removed completely if the property owner
wishes when the project is complete.
Dismantling old towers: The existing towers are being removed
along with the existing conductors. The towers and conductors will be
recycled.
Installing new larger foundations: In some cases the existing
foundations are being removed and replaced or rebuilt to support the new
larger double circuit towers.
New tower construction: The new towers are larger than the one's
they replace and will carry six wires instead of the three wires on
each of the current towers. A complete AC circuit requires three wires
- one for each of the circuit's three phases. The new towers will carry
two circuits or six wires in total.
Stringing the conductor: Once the new towers are in place, new
conductors are strung between them. Modern stringing uses pulleys that
allow large lengths of conductor to be pulled from tower to tower very
efficiently. In some cases, a helicopter is used in this process to keep
activity on the ground to a minimum.
Clamping the conductors in place: Once the conductor has been
strung, line crews visit each tower to remove the pulleys and clamp the
conductors firmly in place at the ends of their insulators.
Access road removal: Once the construction is complete, the access
roads will be removed completely where the property owner requests it
and all their components will be recycled. In a few sensitive areas, road
removal may be postponed until after freeze up so that the work can be
done on frozen ground to minimize environmental disruption.
Environmental restoration: After the project is complete the
whole right of way will be assessed and any necessary environmental
restoration will be carried out such as re-grading, reseeding and other
landscaping measures. In sensitive areas such as the Mer Bleue Bog,
detailed plans are in place to ensure that the bog continues to thrive
after our project in complete.
Photo Gallery
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| Access roads like this one have been built to every
tower location. The crushed limestone placed on geotextile creates
a safe, secure road that can be removed at the end of the project
if desired by the property owner. In areas where the access roads
will encounter water courses involving fishery potential, more expensive
clear stone is used in place of the ordinary crushed limestone. Clear
stone is crushed limestone with the fine particles removed. This prevents
the fine particles from getting into the water and potentially impacting
local aquatic life. |
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Here is an access road built near a tributary of Mud
Creek using clear stone rather than crushed limestone. Note the large
individual stones without the characteristic fine particles found
in ordinary crushed limestone. |
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| The larger new towers require larger foundations. Here
a long cylindrical cage of steel reinforcing bar is lowered into a
large hole that has just been excavated by the auger machine at the
right of the picture. |
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Here workers pour concrete for a new foundation. A reinforcing
bar cage, similar to the one shown in the last picture, is protruding
from the top of the hole. |
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| A large drill is used to drill through the foundations
and into the bedrock below. |
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Grout is then injected into each hole and a long piece
of steel reinforcing bar is slid into the hole and all the way down
into the bedrock. When the grout hardens, these reinforcing bars anchor
the foundation to the bedrock. |
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| Here a tracked vehicle prepares to topple an old tower.
All staff evacuated the tower site and the vehicle toppled it safely
from a distance. |
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Disassembling the toppled tower is easier and faster
than dismantling it from the top down. When the disassembly is complete,
all tower parts are recycled. |
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| In areas where there are poor soil conditions with no
bedrock, much larger platform foundations must be poured. Here heavy
equipment prepares for such a pour. |
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New towers are on the left are complete with their new
conductors. Old towers on the right are to be dismantled. The access
road down the middle of the right of way allows for construction of
both lines and keeps visual disruption to a minimum. |
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| Two additional higher capacity lines out of Hawthorne
TS mean big changes for the station. Here the Hawthorne fences are
being extended to accommodate new station structures. The newly constructed
line entrance structures are visible in the background. |
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Two new 230 kV 3000 Amp breakers on site at Hawthorne
TS. In total, nine will be installed. Four will replace four existing
230 kV 2000A breakers, and five will be added to the station's existing
equipment. |
Back to Top
For More Information
Property owners with whom Hydro One has easement
rights should contact their designated local Hydro One construction contact.
General project inquiries should be directed to:
Carrie-Lynn Ognibene
Community Relations
Hydro One Networks Inc.
483 Bay Street, 8th Floor, South Tower
Toronto, ON M5G 2P5
Tel: 1-877-345-6799 or 416-345-6799
Fax: 416-345-6984
E-mail: community.relations@HydroOne.com
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