FINAL REPORT - International Joint Commission

ANNEX 2
The power entities at Moses-Saunders conduct peaking and ponding operations to better match demand
for electricity with its production. In this way, clean, inexpensive hydropower can be used to offset other
energy sources. Peaking is the variation of the hourly flow about the daily mean flow so that the total daily
flow is equal to that which would have occurred had the peaking not taken place.
Peaking is conducted when the maximum hourly outflows are 7,930 m3/s (280,000 ft3/s) or less.
The maximum allowed peaking range is 850 m3/s (30,000 ft3/s) above/below the daily average flow.
Synapse looked at the incremental value of peak period generation. The period evaluated was short term
and consistent with the emergence of the competitive markets in New York and Ontario. The company found
an average ratio of peak to non-peak energy value of 1.17 for New York, and 1.26 for Ontario; compared
with Moses, the Saunders values are higher and there is a much greater seasonal variation in the ratio.
Hydro-Québec makes very few peaking adjustments at Beauharnois-Les Cèdres.
Ponding is the storage of water on Lake St. Lawrence during the weekend for release during the week
when power demands may be greater. While the power companies still have the authority to pond, they
have done so less frequently over time and rarely do so now. The companies may not reduce flows more
than 570 m3/s (20,000 ft 3 /s) below the average weekly flow on Saturday and Sunday to store water, and
may not increase flows during the week more than 230 m3/s (8,000 ft 3 /s). If the weekly mean flow is
above 7,700 m3/s (272,000 ft 3 /s), the allowances are decreased linearly up to 7,930 m 3 /s (280,000 ft 3 /s),
at which point no ponding is allowed.
6. Expected Consequences of Changes of Regulation
Because the demand and price for energy is expected to be strong over the next few decades, the importance
and value of St. Lawrence hydropower is almost certain to increase. In that light, the Shared Vision Model
may well underestimate the future value of energy, but almost certainly will not overstate it.
7. Adaptive Behaviours
Energy demand is increasing, and hydropower will remain an important component of the energy supply
in New York, Ontario, and Quebec.
The Hydropower infrastructure on the St. Lawrence is a critical component of the International seaway and
power project, and represents a significant investment. Hydro facilities will continue to utilize available
flows to generate in the most efficient manner possible. Any reduction of generation from these facilities
will likely be replaced from a number of sources (combined cycle gas, coal, renewables, etc.) and originate
either from the competitive market, or from sources chosen by the respective province or state.
If lower outflows are predicted for an extended period of time, the power entities would take the
opportunity to perform maintenance and long-term refurbishment of the generating equipment.
8. Risk Assessment
There is some risk that the value of energy estimated in the shared vision model will underestimate the
value of future production from these plants. Substantial changes to the pattern of water supply
experienced in the twentieth century could reduce the dependable capacity of these facilities, and capacity
benefits are not directly addressed in the Shared Vision Model.
120 Options for Managing Lake Ontario and St. Lawrence River Water Levels and Flows