Geothermal Exchange Basics

  There are two types of geothermal energy:

  • core geothermal, energy from the earth's core at depths beyond 14,000 feet
  • geothermal exchange, 46% of the sun's radiant energy absorbed into the upper 500 feet

GT solar absorption

  • Core geothermal can be implemented in 8% of the world's landmass, for example:
    • Banff Springs Hotel
    • Miette Hot Springs
    • Old Faithful in Yellowstone Park
    • the whole country of Iceland

 

  • Geothermal Exchange on the other hand can be implemented everywhere on the planet. Geoexchange is a proven technology with the following approximate number of installations:
 population installations
World 6.6 billion 3.5 million
USA 300 million 2 million
Sweden 6 million 200 000
Canada 32 million 100,000
Alberta 3.5 million 200
 
  • In Alberta, geoexchange systems can be installed that totally replace natural gas. Geoexchange has the advantage of being available all-day and year-round. Compared to photovoltaic electric, solar hot water and wind turbines that are intermittent.

 

  • The oldest known installation in Canada is a residence in Burlington, Ontario, installed in 1950.
 
  • A far-north site that I am aware of is installed in a federal highways maintenance shop, 300 miles north of Whitehorse.
 
  • The main components of a geothermal system installation are:
    1. 4-inch wells, drilled 200 to 300 feet deep (other designs including horizontal loops and pond loops can also be utilized).
    2. high-density polyethylene pipe loops, inserted into the wells (down and up in the same hole).
    3. geothermal grout, poured into the void space. The grout is formulated to conduct the heat from the ground to the pipe.
    4. an underground manifold, with a reverse return header system results in one supply and one return pipe coming up in to the mechanical (furnace) room.
    5. a heat pump, a device that looks like a furnace but uses the same technology as a refrigerator, comes in two basic designs (though some models can do both):
      1. those that create hot air
      2. those that create hot water
    6. Hot-air ducts, similar to a natural gas system but the ductwork is 20% larger.
    7. Hydronics piping (optional), in-floor piping that should be spaced closer together than what is usually done with a boiler.

GT heat pump

  • In Alberta, 74% of a residence's energy requirements (heating, cooling, and hot water) can be met through the installation of a geoexchange system. Most of that yearly energy requirement is needed in the winter when sunshine is limited.
 
  • The approximate cost to install the infrastructure to create one watt of energy is as follows:
hydrogen fuel cell $30
photovoltaic electric module (solar panel) $3
wind turbine $5
geothermal $3
solar hot water $2
  • The environmental impact of installing a geoexchange system in a home is equivalent to taking two cars off the road. Green house gas reductions are significant.
 
  • The introduction of geoexchange technology into the Alberta market suffers from the same fate as many other technology introductions. Our best estimates are that over 50% of all installations are being done incorrectly, even some designed by professional engineers. This happens because of:
    1. a lack of education
    2. arrogance by some installers, drillers, and engineers that think they know it all
    3. a lack of building code rules and adequate inspection processes

  • The Alberta Geothermal Energy Association was formed in March 2007 and received its formal incorporation certificate as a non-profit association in September 2007.Since education and the building code both come under provincial jurisdiction, our association feels that solutions to improve the industry are best met through a strong provincial association.
 
  • The feedback we have received from municipal inspectors in Alberta is that they want installations to be designed and installed by individuals who have taken their instruction from provincially certified institutions, e.g. NAIT, SAIT, U of A, U of C, U of L.
 
  • In North America, the main body of knowledge for this technology was developed by academics at Oklahoma State University. Over the last 40 years, many engineering types at OSU have done research and created textbooks for the geothermal exchange technology. Commercialiaztion of that research and development of training programs was accomplished by creating an industry association that is also headquartered at OSU. The long-winded name for this association is the International Ground Source Heat Pump Association (IGSHPA). OSU is really the Mecca for geothermal exchange in North America.
 
  • Our association responded to the educational need by facilitating an agreement between NAIT and OSU. This agreement was signed in November 2007.
  • Installer training including many unique Canadian enhancements is now available at NAIT as a certificate-level course (GEO101).
  • Technologist training is available through a two year, full time program at NAIT called the Alternate Energy Technologist program or through a two year on-line program called the Renewable Energy and Conservation program at Lakeland College.
  • Geoexchange drilling training is available through a two year apprenticeship program at Red Deer College called the Earth Loop Technician program.
  • Advanced training for engineers is available through IGSHPA Canada.  The program is called Certified Geothermal Designer.

 

Follow up link: Geothermal 101

 
 
 

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