With its wind farm now operational, the Diavik Diamond Mine, located on an island in a subarctic lake called Lac de Gras, is the site of the world's most northern large-scale wind-diesel hybrid power facility. This $31 million project is Rio Tinto's first wind generation facility and the first large-scale wind farm in Canada's Northwest Territories.
The wind farm began delivering power to the mine's grid on 28 September 2012. In 2013, the wind farm reduced the mine's annual diesel fuel requirement by 3.8 million litres and provided 8.5 per cent of the mine's power needs. As well, it will reduce Diavik's seasonal winter road fuel haul by approximately 100 loads. The extreme location of the mine meant a highly innovative design was needed for the turbines, in order to maximize their output in the harsh subarctic climate. With temperatures in the winter as low as -40°C, the blades are all fitted with de-icing technology, and represent a new benchmark for wind power in low temperatures.
The project received capital approval in 2011 and in 2012, all the wind farm components were transported over the winter road - 60 loads were needed including the 33-metre epoxy resin blades (6.5 tonnes each) which were the longest loads ever hauled over the road. Every detail was covered - even customized trailers were required to ensure the turbine components could successfully navigate the winter road's 65 portages.
A key part of the early work was Diavik's renewable energy feasibility study which began in 2007 with the installation of a meteorological tower to collect weather data at the minesite. The three-year study, confirmed Diavik had a strong wind resource.
In 2011, with the study complete, Diavik donated the tower to a local Aboriginal partnership studying the wind resource potential at the old Giant Mine. Located in Yellowknife, Northwest Territories, the Giant gold mine shut down in the 1990s and has long-term environmental challenges. Project partners on this initiative hope that the meteorological tower will demonstrate a viable wind resource and one day lead to a renewable energy source to assist with reclamation of the Giant minesite.
As with the weather tower, Diavik is optimistic that the experience and knowledge gained through the planning, development, construction, and operation of its wind farm will be able to be shared so that other projects can be developed in the future.
Wind farm facts
- Four Enercon E70 generators
- Gearless direct-drive design operating to -40°C
- Total installed and demonstrated capacity: 9.2MW
- 17GWh annual production
- 8 year estimated payback
- Tower hub height: 64m
- Turbine rotor diameter: 71m
- Total turbine height: 100m