Bluefish dam expansion ideas sought
Power corp says one of its two turbines nearing replacement, seeking ideas to generate more power without expanding dam
Shane Magee
Northern News Services
Saturday, May 7, 2016
SOMBA K'E/YELLOWKNIFE
The Northwest Territories Power Corporation issued a request for proposals seeking ideas for the expansion of the Bluefish dam as it comes closer to replacing a power turbine at the facility north of the city.
The Bluefish dam hydro station shows a pipe bringing water down from Bluefish Lake to the two power plants housing power generation turbines. Water flows through the turbines which spin, generating power. One of the turbines, installed in 1942, is nearing the end of its useful lifespan. - photo courtesy of NTPC
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The Crown corporation that last week applied to raise electricity rates in communities across the territory starting in June has issued the RFP seeking a broad look at options at the facility that can provide about 20 per cent of the power to Yellowknife, Ndilo, Dettah and Behchoko. Dams work by having a reservoir of water built up. The pressure of water flowing through the dam turns a turbine that generates power. The two turbines, in separate buildings, have a combined capacity of 7.75 megawatts.
The first turbine was installed in 1942 to power Con Mine and later sold to power corp. in 2003. At the time of purchase, a report included with the RFP states, the generating station would require substantial work or a complete rebuild in the near future.
"The plant is approaching a state where we require a significant capital investment to extend the life of that plant," said power corp. spokesperson Pam Coulter.
She said the company wants to have options to consider before beginning any work, including whether to increase generation capacity to meet future growth in power demand.
"The study is to determine what our options are," she said.
The RFP notes the power corp. expects power demand to grow by 0.36 per cent per year over the next five to 20 years. Last week Coulter said the need for a rate hike was in part because of a decrease in power sales by about two per cent in recent years. She said the decline is not expected to continue long-term.
"So, in this case, when replacing a turbine, we look down the road to ensure it will meet the load requirement of Yellowknife and the North Slave in ?10, 15, 20 years," she wrote in an e-mail.
A previous study by Mitchelmore Engineering Company Ltd., examined options for redeveloping Bluefish recommended an option that would increase generation capacity by 3.44 megawatts but would cost an estimated $35 million.
A refurbishment of the dam completed in 2012 cost $37.4 million. Coulter said the company wouldn't rule out changes to increase reservoir storage capacity.
Last year Yellowknifer reported Bluefish was only generating 13 per cent of its capacity due to low water levels in the region. That in turn led to a greater dependence on diesel fuel to power the city.
The study is also expected to examine the second turbine, which RFP documents state "has shown problems with excess vibrations."
The RFP document also states the study should look at the cost of building an all-weather road to the site which is now accessible by helicopter, winter road, or boat in the summer.
The request for proposals for the expansion study closed May 2. The cost of the study won't be available until a proponent is selected.
