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A Word From The President
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OFFER AND DEMAND
Canadian geothermal history is mostly one of drilling. This is particularly true in Quebec, where more than 95% of geothermal projects involve vertical boreholes.
The geothermal market is experiencing a sustained high growth rate. There is now an ongoing challenge to keep up with demands. In 2002, offer (installation capacity) was greater than demand (customers eager to choose geothermal technology), this situation is about to be reversed. In fact, it is now around commercial projects that we find the highest increase in demands (proportionally). A joint study produced by Natural Resources Canada and the CGC, published in December 2007 in the CGC's GeoConnexion magazine, notes that requests for heat pumps over 10 tons in capacity have multiplied by a factor of five (5) since 2002!
In Quebec, the institutional market is experiencing the greatest growth, propelled by a governmental will to improve energy effectiveness throughout all their premises. The repercussions of this rise are not entirely positive. The geothermal industry's main challenge, in the medium term, is to structure itself adequately to fulfill this increasing request. Odds are that the industry's bottleneck will come from lacking drilling capacities.
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Latest News |
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Training for Commercial System Designers® is an integral part of the of the Canadian GeoExchange Coalition's (CGC) Global Quality Program for geoexchange systems which also aims for gradual transformation of Canadian geoexchange markets.
This specialized course approaches in a structured manner the design of complex geoexchange systems thus fitting in a tendency aiming at raising standards and practices in geothermal installation systems design. This course is also the prerequisite before applying for CGC commercial geothermal systems accreditation.
CGC training, individual accreditation and residential systems certification are already required to have access to various subsidies from the federal government, energy utilities, banks and several provincial governments in Canada.
Although no Canadian financial assistance program currently requires a CGC accreditation for commercial geoexchange systems design, talks are on-going with several provincial governments, energy distributors and financial institutions so that this course and the CGC accreditation becomes part of the necessary requirements to tender and carry out geoexchange projects for the commercial and institutional buildings market and profit from financial assistance and subsidies.
By:
Denis Tanguay
President and CEO / Président-directeur général
Canadian GeoExchange Coalition / Coalition canadienne de l'énergie géothermique
1030 rue Cherrier, Bureau 501
Montréal (Québec) H2L 1H9
Téléphone/Phone: (514) 807-7559
Télécopieur/Fax: (514) 807-8221
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Geo-Energie Tips and Tricks
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Antifreeze; Which one to choose
Our last publication exposed the pros and cons of various antifreeze families generally used in geothermal systems and presented six different possible impacts on the whole of a project based on the antifreeze chosen.
We will now dig into more technical aspects of antifreeze selection.
Energy savings is the main reason to choose geothermal solutions, i.e. to set up the most powerful geothermal system possible at the lowest possible cost. Obviously, cost and performance are generally two antagonistic principles. It is thus necessary to make judicious compromises to reach our objective: a project which is both effective and profitable.
That being said, which antifreeze should we choose? As we mentioned in a prior article, the choice of antifreeze is mainly the customer's call, with, of course, the designer's technical support.
1- For the customer, the following elements will be considered:
- Costs (Antifreeze, Filling, Maintenance, Pumping Energy)
- Environmental Impact
- Security
- Impact of the chosen system's piping material (cost)
- Impact on the geothermal system's global energy savings.
2- For the designer, the following elements will be affected
- Low Temperature Viscosity
- Specific Heat
- Toxicity and Flammability (necessary safety devices)
- Availability
- Lifespan and Potential Reactivity
- After use Disposal Method
- Compatibility with piping materials and other hydronic accessories.
- Price
Continued Top-Left
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Geo-Energie Tips and Tricks (continued) |
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(continued)
3- Reasons that influence a customer's preference for one type on antifreeze over another differ from those of the designer in several ways. All selections are good, so long as their reasons are known, pondered and explainable. Several of these reasons are qualitative or economic. We will not dwell on these elements. We will however go into the technicalities of certain reasoning, so as to demystify them.
A) Viscocity:
When the time comes to choose antifreeze, one often hears the viscosity argument as being justifiable proof for the use of alcohols instead of glycols. We will thus use an example to review several fundamental geothermal principles.
1- Contrary to popular belief, it is not to protect the underground geothermal piping from freezing that antifreeze is necessary in the circuit. The presence of antifreeze in a geothermal circuit, besides some rare exceptions, is justified by a single reason: To prevent the liquid coolant from freezing in the heat pump's evaporator-coolant exchanger (cold side heat exchanger).
2- The evaporator is the heat pump's coldest area, capable of reaching, at a molecular level, 10°F below the temperature on the outlet side of the evaporator. For example, if the ground loop is designed to operate at a minimal temperature of 32°F Entering Water Temperature (EWT) of the heat pump, the temperature on the Leaving Water Temperature (LWT) side of the evaporator will be of approximately 26°F. The liquid coolant's coldest foreseen molecular temperature will thus be of 16°F. It is therefore necessary, in this case, to select an antifreeze mixture for a minimal protection of 16°F.
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