By Dave Coper, Edmonton Journal, February 17, 2010
Tiny nuclear reactors originally designed to power mini-submarines could eventually replace wind power in a local firm's plans for storing energy as compressed gas in pipelines across North America.
Dave McConnell, president and CEO of Niskubased Lancaster Wind Systems, said Tuesday the additional details of his project can now be discussed after provisional patent protection was gained in the U.S. late last week.
McConnell said he already has a patented wind turbine that will be going into further trials this summer in southern Alberta.
Instead of generating electricity from a turning propeller shaft, like all other turbines on the market, Lancaster's version resembles a hydraulic pump much like a windmill. A closed system circulates fluid up and down the mast, with the energy being used at the base to compress nitrogen gas in a large cylinder as a means of storage.
But the heart of Lancaster's scheme, which the firm says has attracted millions of dollars from private investors in Canada and the United States, is energy storage with compressed gas, making wind power a constant source of energy instead of one totally dependent on variable winds.
As it is released, the nitrogen turns an electrical generator inside a closed system, which then returns to the pipeline.
McConnell said because of the huge size of the proposed system, which would use existing pipeline routes through Alberta and the U.S., pressure can be added anywhere and removed from any point.
And by using just seven mini-reactors, each with a rated power of three megawatts running compression units spaced every 1,200 kilometres, pressure in the system can be maintained.
"We had always planned to use the micro-reactors in phase two sometime after 2015. But we just got conditional patent approval late last week for our compression technology, so now we can talk about it a bit," McConnell said.
Canadian nuclear builder CANDU is bidding to supply the micro-reactors, which weigh 42 tonnes and are the size of a car. The cost of installing such a unit is estimated to be about $50 million, he said.
One reactor would be in the Chain Lakes-Pincher Creek area, with a second between Montana and Idaho and another one in Arizona. The compressed-nitrogen pipeline could extend through the U.S. Midwest and south to the Gulf Coast.
Bill Kennedy, an engineering consultant to Lancaster and former head of the Alberta Electrical System Operator which manages power in the province, said McConnell's idea is clever.
"The energy in the compressed gas can come on as the grid builds to its daily peaks -- breakfast and dinner times. And the closed nitrogen gas system is analogous to coal or gas-fired plants," he said.
"You release the steam through the turbine, and end up with hot water, which is reintroduced into the system, so you aren't losing the energy in the hot water and you don't have to start with cold water."
In the end, that means the compressed-gas system will act more like a base load generator such as a coal-fired generator, which runs constantly with an even output.
But with wind farms sprouting up all over North America at a rapid rate, Kennedy doesn't expect they'll be replaced by nuclear-powered gas compression.
"I think wind turbines will be a dinosaur in 25 years."
The former oilpatch vet, who spent his life operating and designing hydraulic equipment for offshore drilling, said his system is based on well-known technology, such as pipeline gas compression and hydraulic energy transfer.
This summer, a project named "Two Islands" will be the first field test for his system, when a short pipeline segment will be installed at a development and his windmill will pressurize the gas-filled line, creating electrical energy from the stored pressure.
"I think that will open a few eyes," he said.
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