What will be, once completed, the first geothermal power plant in Canada, is now under construction in Saskatchewan, according to recent reports.
The planned pilot plant for the project is set to total just 5 megawatts (MW) in capacity, but the potential is there for the geothermal resource being tapped to provide hundreds of MW of generation capacity, reportedly.
Preparations for the pilot plant’s development began at the leased site in question, roughly 2 hours drive southeast of the city of Regina, late last year. The company behind the project — Deep Earth Energy Corporation — is reportedly still in the process of securing funding for development, it should be noted. The company’s CEO Kirsten Marcia recently noted that, with $4 million already spent on feasibility studies, another $5 million would have to be raised from investors “before she can receive approval for the loans that will finance construction of the plant itself.”
Presuming electricity prices in Saskatchewan (~$0.10/kilowatt-hour) remain somewhat level within the near-future, estimates are that the $40 million project could pay for itself in under 15 years. Notably, the facility would then be expected to remain operational for (at the very least) several decades after the pay-back-period.
Here’s some background via Vice:
The company is taking advantage of existing oil industry data to skip the high cost of exploration, and is using new drilling technology that the company claims is earthquake-safe. It also helps that the Saskatchewan site is in a populated area where the locals are no strangers to energy development, and access roads already exist. If successful, the company’s planned 5 MW pilot plant will produce enough energy to serve around 5,000 homes.
…Typically, a geothermal developer will drill multiple foot-wide holes several kilometers into the ground. These holes bring hot water to ground level where it flashes into steam due to the considerable pressure change, and the steam drives a turbine to generate electricity. But in Saskatchewan, the hot water aquifers are not only deeper, but also not hot enough to flash into steam once the water reaches the surface.
With binary cycle technology, hot water is brought up to the surface and into a heat-exchange chamber where it makes contact with a heat transfer fluid — usually isobutane, which has a low temperature boiling point. As the fluid boils, the resulting isobutane vapour drives a turbine to generate electricity. Once the isobutane vapour condenses, it is pumped back into the heat-exchange chamber to repeat the process again. The hot water, which loses heat after coming into contact with the isobutane, is reinjected into the ground where it quickly picks up the Earth’s heat and is soon ready to be brought to the surface once more.
Interestingly, the facility will be making use of a geothermal resource — a 40,000 square kilometer aquifer with a temperature of around 120° Celsius — that was first discovered by the US oil company Amerada Petroleum back in the 1950s. To put that number in perspective, the aquifer in question is bigger than Vancouver Island — so there seems to be quite a lot of potential there.