Published on June 30, 2012
A 1 to 70 scale model of the Muskrat Falls generating site, seen here under construction, was built by Northwest Hydraulic Consultants of Edmonton in July 2011. Covering about half a hockey rink, the model — including the North and South dams, powerhouse and spillway — was used for hydraulic testing of the plans for the hydro dam. Over 200 tests were conducted before it was dismantled, according to information provided by Nalcor Energy. — Photo courtesy of Nalcor Energy
Published on June 30, 2012
The Lower Churchill project team tested three models for a generating turbine for the Muskrat Falls hydro facility. The front-end work will improve operations and help avoid costly changes down the road, should the project go ahead, according to Nalcor. — Photo courtesy of Nalcor Energy
About $5 million spent on scale-model dam, turbines
The up-front investment by Nalcor Energy into engineering and design work on the Lower Churchill project has been described as “extensive and appropriate” by leaders of the Crown corporation.
With the project yet to be sanctioned, the reason for the spending to date has been questioned.
The spending has covered an array of items — legal evaluations and financial consultations, for example. Yet it has also been used for “front-end loading,” with engineers conducting in-depth analysis of project components and searching for any potential hiccups that might be encountered with project design, making adjustments as required.
“By taking a front-end loading approach, Nalcor increased the quality and accuracy of the development plans for Muskrat Falls. The company also mitigated many risks that could arise during construction potentially impacting both schedule and cost,” states a response from Nalcor staff to questions on the work.
In a presentation at the annual conference of the Newfoundland and Labrador Oil and Gas Industries Association, held June 12-21 at the St. John’s Convention Centre, Nalcor vice president Gilbert Bennett provided a description of some of the front-end work the project team has done.
Engineers started with detailing Muskrat Falls. They moved to computer models and further defined their plans. Next came the construction of tangible scale models. Nalcor contracted outside the province for the creation of the models.
The Telegram was told there was no capacity for this modeling work in the province.
Northwest Hydraulic Consultants in Edmonton, with a head office in Vancouver, constructed a 1 to 70 scale model of the Muskrat Falls dam site in July 2011. The model required about half a hockey rink worth of space to lay out, according to Nalcor representatives.
Hydraulic testing was conducted using the model. For example, as water was run to the hydro dam, small shots of coloured die were dropped in, allowing engineers to monitor water flows.
Engineers also tested how the design withstood severe environmental conditions, including flooding.
The need for small changes to the design — for the protection of the facility, or to maximize energy production — became evident. Adjustments were made and evaluated using the model.
In addition to the mini version of the site, the project team sought further information on the generating turbine to be used for the hydro facility.
“All it is, is a big fan. A huge fan,” explained Nalcor Energy CEO Ed Martin, during an interview with The Telegram. “The water hits that and turns it like mad and it’s that motion that gets translated in the generators, that turns the generators and that gets translated into the electricity.”
Contracts were awarded in February 2011 for three different scale models of the turbine options, to the three largest turbine manufacturers in North America — Andritz Hydro, Voith Hydro and Alstom Power.
The modeling work, including simulated water flow and making alterations to maximize output, was completed in March 2012.
“The shape and form of that, how the wings are shaped, is very critical to the amount of power you get out of it,” Martin said.
“Certainly, the physical modeling did identify issues that we have incorporated now in our final design,” Bennett told NOIA members.
“Had we not done that work, we would have had to ultimately have made compromises in the engineering design and we would have had a lesser quality product at the end of the day than what we can see at this point in time.”
Bennett said similar comments could be made about separate front-end work on the cable which will cross the Strait of Belle Isle and preliminary work at Gull Island.
Nalcor is spending about $5 million on the generating site modeling and turbine testing in total.