Canadian Geothermal Energy Poised for Takeoff
Geothermal energy is abundant in Canada from coast to coast, particularly in BC and the Yukon; these areas overlie the extremely tectonically active Pacific margin. However, Canada has lagged behind other countries on the Pacific Rim in terms of the development of high temperature geothermal power. The reason for this inactivity can be attributed to a variety of factors, including traditionally low energy prices, especially cheap hydro and natural gas. Nevertheless, since the turn of the millennium, there has been a shift towards increased geothermal power production due to increased gas prices and a commitment to greenhouse gas (GHG) reduction.
In Canada, high-enthalpy hydrothermal resources are specific to BC and the Yukon, while medium-temperature resources are present in BC, Yukon, Alberta and the Northwest Territories; nearly 150 hot-springs of temperatures up to 80°C have been reported. Furthermore, the western Canadian sedimentary basin that stretches from the Rockies in the west to the Canadian Shield, is a large resource of deep-circulating lukewarm to warm waters (reaching 50°C). In fact, it is estimated that the energy value of the extractable geothermal energy from the waters in this basin is more than the total Canadian oil and gas reserves.
Low-grade geothermal heat pump technology is usable from coast to coast and is considered as the fastest growing ‘green energy’ alternative in Canada; the direct use application of low to medium grade geothermal resources may play a critical role in the Canadian commitment to reducing GHG’s. As for the lukewarm waters in the sedimentary basin, one proposed usage is bitumen extraction from oil sands.
In regards to commercially developable high-temperature geothermal resources, they amount to at least 1500 MWe in BC, primarily associated with the Garibaldi Volcanic Belt in the south of the province. The interest in these resources spiked after the 1973 oil crisis, which led to exploration activities and detailed fieldwork in the south-west part of BC where there was already power-line infrastructure in place. Several anomalies were discovered after this period, including Mt. Meager, near pemberton, and Mt. Caley, near Squamish, BC. The former became the focus of the provincial and federal governments, and high enthalpy reservoirs were identified after extensive core drilling. Unfortunately, worked stopped in 1985 due to the financial constraints of B.C. Hydro. The geothermal industry was relatively inactive in the 1990’s, only to be revived at the turn of the Millennium that brought rising energy prices and greater focus on GHG reduction.
The South Meager project was revived in 2000, and 2001 and 2002 drilling activities discovered temperatures of up to 224°C at depths below 600m. Temperature data also suggested the presence of temperatures of 250°C at depths less than 2500m. The geothermal power reserve of South Meager Creek, based on volumetric heat content of the upflow zone, is estimated at 250 MW, with 110 MWe as the most secure part of the resource – this has significant potential for BC’s commercial geothermal development.
The North Meager (or Pebble Creek) reservoir has been the subject of a feasibility study and review of previous drill-hole data. Based on borehole data and geophysics, geochemical, and geological evaluations, the potential for high-capacity commercial development is estimated at 300 to 500 MWe. Plans for deep confirmatory drilling have been proposed for this prospect.
The geothermal heat pump (GHP) industry is growing in Canada at an exponential rate; over 30, 000 heat pumps had been installed in Canadian residences and commercial/institutional outlets by the year 2000, and in 2004, over 3000 new systems were installed. Additionally, the Canadian government’s plan to install GHP systems in many of its buildings across the country is expected to double GHP use over the new few years.
GHP’s generally have higher capital costs than alternative heating and cooling systems, with a payback period of 2 to 10 years. For open-loop schemes, however, the payback period can be as low as 1 year for medium to large-scale systems. Factors that could improve market penetration include incentives such as rebates or low interest loans offered by energy utility companies. As an example of such initiatives, Manitoba Hydro offers an 8.5% Residential Earth Power Loan of up to $15, 000 to cover additional costs of GHP systems. Total GHP energy saving in Canada is estimated at 600 million KWh in terms of space heating and cooling, translating into a reduction of 200, 000 tonnes of GHG emissions.
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Canadian Geothermal Energy Poised for Takeoff
Ghomshei, M.M; K, MacLeod; TL., Sadlier-Brown; J.A., Meech; R.A., Dakin, 2005