Managing hydropower reservoir operations is a tricky science. It involves the ability to accurately predict how much water should be saved in
reservoirs so that the utility can continuously produce
energy, especially when electricity prices are high.
Many utilities struggle with this challenge because
it is difficult to produce accurate inflow forecasts.
To make this decision, utility Hydro-Quebec analyzes daily rainfall or snow melt forecasts to determine the amount of potential inflow to its reservoirs. The utility — which generates, transmits and
distributes electricity for the entire province – faces
the challenge head on with the help of geographic
information system (GIS) technology.
With 62 hydroelectric generating plants and 27
large reservoirs, Hydro-Quebec is the largest elec-
tric utility in Canada and one of the world’s largest
hydroelectric producers. The government-owned
utility has been successful in generating large quan-
tities of renewable electricity at competitive prices
due in part to its technological innovation. This in-
novation is evident in how the utility manages its
It takes a 10-person team to validate the data that
will be entered into mathematical models to support decision-making. Every day, Hydro-Quebec’s
in-house meteorologist compares weather forecasts
from Environment Canada, as well as forecasts from
the U.S. and European models, to determine
differences and modify the Environment
Canada forecast model to be used for analysis. At the same time, other staff members
validate other data, including reservoir levels, water flows and power flows.
After the forecast of how much water
will fall into the reservoirs is made, operators then schedule how much energy will
be produced for the next day.
Recognizing the value of
a geographic approach
In 2006, Hydro-Quebec developed home-grown GIS software to assist operators with
their decision-making. However, the system
lacked a real geographic component and
had limited visualization and analysis capabilities. It integrated bitmap images of rain
coming into the reservoirs, but the images
were not associated with their location. As
well, it was difficult to understand the representation because multiple layers of lines
were overlaid on top of one another.
To help improve the accuracy of its forecasts, Hydro-Quebec leveraged ArcGIS
Hydro-Quebec used Esri’s ArcPy tools to
script GIS functionality in the Python programming language to build a program that retrieves weather forecasts by Environment Can-
By Francois Gilbert
Francois Gilbert is a senior
water resources engineer for
Streamlining Operations with Software
By creating a new suite of analytical software, Canadian utility Hydro-Quebec was able to
build a system better suited to managing its dozens of reservoirs while more accurately
balancing water resources and power generation.
Hydro-Quebec’s previous system could only display one layer of data at a time. In this image, a 24-hour
rain forecast is shown using isolines.
Figure 1 — The Old System