Hydroelectric energy is a renewable energy source dependent upon harnessing the flow of water due to gravity. Canada has abundant water resources and a geography that provides many opportunities to produce low-cost energy.
Hydroelectric energy is the main source of electricity in Canada, representing nearly two-thirds of all electricity produced. Most of this hydroelectricity comes from large projects developed by electric utilities.
Canada is the world leader of hydroelectricity production, followed by the United States and Brazil. In 2002, Canada had an installed generating capacity of 67,121 megawatts (MW). A high electrical energy production rate of 59% was achievable due to the use of large reservoirs.
Hydropower in Yukon
Yukon, with its mountainous terrain and wealth of rivers and lakes, is ideal for hydro-electric generation. From the days of the Klondike gold rush, visionaries have imagined schemes to harness large volumes of water. However, it has been more modest visionaries, driven by the demands of mining, who have built most of our hydro facilities.
Today, because of the Territory's isolation and relatively small electrical production, Yukon is not part of the North American power grid. Instead, Yukon has its own Whitehorse/Aishihik/Faro (WAF) system, which services about half the communities, and the Mayo/Dawson City system which serves Mayo and Dawson City as well as customers between these two communities.
Electrical power generation in Yukon has almost always gone hand-in-hand with mining. The first hydropower plant was built in the Klondike during the gold rush. This facility produced power for the mining operations during the hayday of the Klondike gold rush and is no longer in operation.
During the first half of the 20th century, Whitehorse's electricity was generated by wood and, later, by diesel power plants. In 1948, John Scott and his brother-in-law, John Phelps, started discussing the possibilities for hydroelectric power. In 1950, the #1 Hydro plant began operation on the Fish Lake Road followed by #2 Hydro plant in 1954. Today, the two plants continue to feed power into the Yukon power grid.
Originally built in 1951 at a cost of $500,000, the Mayo storage dam is still in use despite having an anticipated life of just 15 years.
Downstream of the Mayo storage dam, at Wareham Lake, engineers constructed a 32-metre high earthen dam with a concrete spillway. The intake structure fed water to a 2,500-kW power plant turbine through a tunnel to the powerhouse below the dam. The plant was officially commissioned in November 1952. In 1957, a second unit was installed in the powerhouse, bringing the plant’s generating capacity up to 5,150 kW. The plant is capable of producing an average of up to 43 GWh of electrical energy per year. Recently, a transmission line has been constructed from Mayo to Dawson City which allows the Mayo dam’s excess power to displace Dawson City’s diesel generated electricity. This reduces greenhouse gas emissions by up to 16,800 tonnes per year and contributes to a significant savings in diesel fuel.
The Whitehorse Rapids generating facility was built in 1958 at a cost of $7.2 million. It began with two hydro turbines, and in 1969 a third one was added. A fourth turbine was installed in 1985, doubling the capacity of the plant. The current capacity of the Whitehorse Rapids facility is 40 megawatts in summer and approximately 19 Megawatts in the winter when water levels are naturally lower.
In the early 1970s, NCPC began planning for an Aishihik Lake power station to help meet Yukon's increased power needs.
The Aishihik dam includes storage control structures at Aishihik and Canyon lakes and a 5.8 Km canal from Canyon Lake to the intake structure. The water then flows more than a kilometer through an underground shaft and tunnel to the first underground powerhouse north of the 60th parallel. There, water powers two turbines driving a pair of 15-MW generators before exiting through a 1.5 Km underground tunnel into the Aishihik River.
Micro-Hydro in Yukon
Not all hydro projects require major water diversions and dam construction. If water can be drawn from a higher location and piped to a lower hydro turbine, the resulting head — the power of the falling water — can be used to generate power. On a small scale, this kind of system is often referred to as micro-hydro.
For over 20 years, Doug and Cindy Gilday have lived on the Carcross Road, where they have raised three children and not paid a cent to an electrical company. They run electric lights, small appliances and their home and business computers from power they generate in their own backyard.
A small reservoir was dug on a glacial outflow plain uphill from the house. From a screened inflow box, 400 feet of buried PVC pipe brings water to an enclosed cross-flow turbine. The turbine powers a generator that charges a bank of deep-cycle storage batteries. Gilday says that it is a simple, reliable design that the Canadian International Development Agency has used in third world projects. The system reliably produces about 1,200 kWh of power per month, roughly $100 worth at utility prices.
NEW ERA Hydro Corporation generates power from Fraser Lake to supply the Fraser highway camp and Canada Customs. Today, aside from the access road, the only visible disruption at the site is a small shelter that protects a valve between the intake and penstock. At Fraser, a structure houses a Pelton wheel turbine and a 250-kW generator. Construction of the $550,000 facility was self-financed with assistance from the Yukon Energy Alternatives Program. Since it was commissioned in 1990, the plant has been largely trouble-free, running 99.9% of the time for the last 16 years.
The Future of Hydropower in Yukon
Construction of large hydro facilities in Yukon has almost always been driven by new mining developments that promised significant power sales over a long period of time, sometimes bringing improved services for other electrical consumers. The 1998 permanent shutdown of the Faro mine, which had been the single largest power consumer for many years, meant that Yukon had an excess of power. New mines, of a smaller scale than the Faro mine and a commercial heating program, are increasingly reducing this excess. Thus, Yukon Energy is looking for new hydro possibilities along with other renewable forms of power.
Future growth capacity will likely come from smaller, renewable developments. These could include hydro sites near communities and energy transmission corridors in various parts of the territory. In the meantime, Yukon is continuing to generate most of its power from clean, reliable hydro.