| Brief
History of
Transmission Issues
in the Region
Introduction
The
history of the Lamoille Transmission
Upgrade Project dates back three decades.
In
1976, the Vermont Electric Power Company (VELCO), the utility
that builds and operates transmission
lines throughout the state, recommended that four utility
companies serving Lamoille County build an emergency tie to
strengthen the electrical grid network among themselves for
increased reliability. VELCO warned at the time that this
would only be a temporary fix, and that ultimately it would
be necessary to bring in substantially more power into the
region. Analysis at the time concluded that, while the emergency
tie would delay the expenditure on a new 115 kV
transmission line,
such a line would eventually need to be constructed.
Load
Growth
The
emergency tie and other smaller temporary fixes were completed
in the late 1970s. They helped to maintain reliability,
but with continued development and demand on the system, its
inadequacies again became apparent in 1986. At that time the
Public Service Board (PSB), the quasi-judicial authority that
regulates Vermont's utilities, ordered that Lamoille County
utility companies convene to work out a solution to the problem.
Numerous meetings were held among the utility companies serving
the area, but no resolution was reached. The disagreements
centered in large part on how the cost of the improvements
would be divided up among the participating utilities, including
Green Mountain Power, Morrisville Water and Light, Stowe Electric,
and the Hardwick Electric Department.
Green
Mountain Power, VELCO, and Central Vermont Public Service
conducted further studies from 1987-1992. The conclusions
from these studies all showed the need for system upgrades
to maintain the reliability of the system. No action was taken
until 1993 when Morrisville Water and Light filed an application
to rebuild the power line that runs from Johnson to Morrisville.
The Morrisville Water and Light project was completed in 1996
and was the last significant power line upgrade in the county.
Current
Capacity
As
a result of continued load growth, the subtransmission system
that delivers power to utilities in the Lamoille County area
is at its full capacity of 75 megawatts. At this level of
demand, a single
event such as a fallen power line or damage to a key piece
of equipment could cause black outs. The proposed 115 kV line
and associated equipment currently under consideration in
Docket 7032 would increase the capacity of the area's subtransmission
system by approximately 25 megawatts.
Proposed
Build and Costs
In
2003, the Lamoille County utilities asked VELCO to develop
a longer-term solution to the system limitations shortage.
After studying a number of alternatives, VELCO proposed building
a new 115 kV line from Duxbury to Stowe. Stowe Electric is
paying for a large share of the construction costs and the
costs of the approval process. The estimated $20 million costs
for the project will be shared by other utilities in the region.
Note:The
Department of Public Service thanks the Stowe Reporter for
its contribution to this piece.
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