Canadian Consulting Engineer

Feature

Whitehorse Diesel to LNG Conversion – Award of Excellence

Jury Comments: “This is a “first of its kind” project creating a standalone generating station fuelled by liquid natural gas (LNG) to feed into a small hydro grid. The experience gained here can be leveraged for further LNG use across Northern Canada to reduce the reliance on diesel for back-up power, with its associated greenhouse gases. The project also involved the local community and First Nations in the construction.”


Yukon Energy Corporation's LNG plant in Whitehorse.

Yukon Energy Corporation’s LNG plant in Whitehorse.

From the October-November 2016 print issue, p. 59

Delivering reliable power to the residents of the Yukon with its Arctic and subarctic climate is important and challenging. The isolation of Yukon’s hydro-based electrical system from North America’s grid, along with spikes in demand from weather, transmission and hydro generation failures, all add to the challenges.
This project added an 8.8 MW liquid natural gas (LNG) fuelled power generating station, improved the system’s reliability, and reduced both the costs and the environmental impacts of generating power.
The project was also ground breaking for oil and gas regulators in the Yukon: LNG had not previously been stored, nor used as a fuel for electrical power generation, in a greenfield facility of this scale.

Project drivers
In 2012, 99% of the Yukon’s electrical grid drew power from 93 MW of renewable hydroelectric and wind power. That capacity was supplemented with 42 MW of back-up diesel power produced by the Yukon Energy Corporation’s aging thermal generating equipment.
The diesel back-up generators were increasingly viewed as a reliability risk. Therefore, Yukon Energy Corporation, with First Nations support, and a $21 million investment from the Kwanlin Dun Band, decided to build an LNG fueled power generating station, improving reliability, reducing power costs and environmental impacts.
Yukon Energy Corporation assembled a team comprising Allnorth and CAP for project management, and KGS as design consultants. The corporation’s in-house engineering team was also engaged.

Plant features
Constructed adjacent to the Whitehorse Rapids Hydroelectric Dam and Thermal Generating Station, the new plant includes three large LNG storage tanks and a vaporization unit, which converts the liquid to gas and then feeds that gas into the reciprocating engines that drive the generator.
The facilities as commissioned in 2015 include two reciprocating generators (total of 8.8 MW) with allowance for a third generator to bring the total capacity to 13.2 MW. The related infrastructure also includes a fluid (oil/glycol) transfer station, a small electrical substation to receive power from the generating units, and a switchgear module.
Cutting edge LNG power generation modules were used; efficiency tests during operations have surpassed expectations.

Site complexities
Extraordinary vapour dispersion computer modelling efforts were necessary since the site was near a major access road and the Yukon Energy Corporation headquarters. The design also had to conform to the requirements for seismic conditions and account for granular subsoil and high water table conditions on the site.
Through the use of 3D modeling and intense project management, the team was able to coordinate their designs and onsite work and limit the plant’s footprint.

Environmental, social and other benefits
• Substantial annual fuel savings
• Reduction in electrical outages
• Reduction in pollutants
• Noise reduction and improved reliability
• Environmental impact of a LNG spill would have less impact than a similar sized diesel spill.

 

Whitehorse Diesel to LNG Conversion Project, Yukon
Award-winning  firms:  Allnorth Consultants – owner’s project manager  (Janna Gillick, P.Eng., Phil Bell, P.Eng., Ian Rothera, Marg Branchi, John Murray, P.Eng.); KGS Group – design (Hugh Williams P.Eng., Ashley Dent, P.Eng, Helmut Grauman. P.Eng.); CAP Engineering – construction management (Curtis Gamache, Kyle Power, Bob Brown, P.Eng.)
Owner/client: Yukon Energy Corporation (YEC)
Other key players: Intergroup Consultants (feasibility reviews and permitting)