Chilly Climes

Chad Gubala envisions a suitcase-sized gadget capable of powering a typical home, fuelled by the one resource the Yukon has no shortage of: the cold. It sounds like science fiction.

Chad Gubala envisions a suitcase-sized gadget capable of powering a typical home, fuelled by the one resource the Yukon has no shortage of: the cold.

It sounds like science fiction. But the technology, in various forms, has existed since 1816.

It’s called a Stirling engine. To run, all it needs is a source of heat and a source of cold.

Today Stirling engines are used to power remote lighthouses and ultra-quiet submarines. Gubula hopes to see them help power Yukon’s telecommunications network, and, one day, people’s homes.

Gubala was appointed last month as director of Yukon College’s applied science arm, the Yukon Cold Climate Innovation Centre.

As such, he straddles the worlds of academe and business. Or, as he jokingly puts it, pride and avarice.

This means that getting a Stirling engine to work in a lab is only part of the puzzle for him. He wants to build something people will use.

Good thing, because Yukon College already has a menagerie of green gadgets that currently sit unused. To wit: solar panels, a wind turbine and a fancy furnace that vapourizes wood-chips.

Gubala already has a potential customer. Northwestel has partnered with the college for the three-year project, and is pitching in $50,000 of the project’s $120,000 annual budget.

The company is interested because it has more than 100 microwave towers scattered across Canada’s North. These stations, which provide the backbone to Yukon’s telecommunications network, are expensive to operate and maintain.

Because they’re off the power grid, the stations are powered by diesel. Because they’re often far from access roads, they must be periodically resupplied by helicopters slinging bladders of fuel.

And those helicopter trips are expensive.

Enter the Stirling engine, named after the Scottish clergyman Robert Stirling who patented the invention in 1816.

Unlike internal-combustion motors, which power our cars, lawnmowers and diesel generators, the Stirling engine is powered by outside temperature differences.

At the heart of a Stirling engine is an enclosed gas chamber. In simplified form, the chamber is heated at one end and cooled at the other, causing gas to alternately expand and contract. The machine is rigged so these gas movements power pistons. Heat is transformed into mechanical energy.

Older Stirling engines depended on temperature differences of several thousand degrees. But Gubala believes today’s technology could produce a Stirling that could squeeze out two to five kilowatts of power from a temperature difference of 100 degrees Celsius.

“It allows us to get more efficiency from using our cold, which is a counter-intuitive concept,” said Gubala.

Because the engine depends on heat as well as cold, a Stirling wouldn’t be able to produce power by itself. But it could offer big energy efficiencies over diesel alone.

For Northwestel’s stations, a Stirling engine could provide fuel savings of 20 per cent, Gubala figures. Doing a quick back-of-the-envelope estimate, “that adds up to a couple million bucks pretty quick,” he said.

Gubala soon hopes to hire a post-graduate researcher to lead the Stirling project over the next three years. The first year will focus on selecting the right model from a dozen different global companies.

To leverage more federal money for the project, Gubala proposes to partner with the University of Alberta and the University of Northern BC.

The finished project could power a lot more than satellite towers. For example, “it’s a beautiful system for people living off the grid in the Yukon,” said Gubala.

“We’re really looking at this having a lot of legs.”

And the gadget’s development in the Yukon should give time to educate suppliers and local mechanics, so that when the engine is ready for use there would be a supply chain waiting for it.

“The last thing we want to come up with is something really cool that nobody can support,” said Gubala.

That would seem to set the Stirling engine apart from Yukon College’s other green gadgets.

Gubala has bigger ambitions than that. He has high hopes the right Stirling engine design could place Yukon in the centre of a high-tech hub of global companies and Outside universities.

“This is how the North is going to develop. That’s how we’re going to shine.”

Contact John Thompson at johnt@yukon-news.com.