GEOTHERMAL IN CANADA? 3

[08201950]

is it just a fad or is it practical to use geothermal energy to heat a house in canada?
i understand in toronto, the earth temperature 400' down is about 55 degrees year round.
how much heat can we extract from this relatively cool part of the earth?
what'd happen to the earth if every household starts drilling 400 foot deep holes into the ground?

 

[Wizeman]

Geothermal energy is a very good and stable energy source. The available capacity depends on the type of soil and amount of ground water.

Generally though in southern Canada the ground temperature is 7 to 8?C below 30-40 feet. This means that if you have enough ground water (for an open system) or enough exchange surface (for a closed loop system) you can go ahead with geothermal.

I suggest getting a soil study done by a specialist to make sure it can be done where you are (which I am positive about) and get a consultant to design your system.

The source of geothermal energy is actually the sun which heats the earth and the ground absorbs this energy. In other words, unless the sun burns out in your life time there will always be geothermal energy available.

A quick final note: geothermal is sometimes seen as a fad and although it is true that it's popularity comes and goes (due to fluctuating energy prices) it remains a real way to reduce heating and cooling costs by a factor of 3 or more.

I hope this clears things up for you.

 

[GMcD]

Geoexchange systems with water to water heat pumps as well as traditional water to air heat pumps have been used for over 30 years in Canada. It's all about sizing the loops properly with very good soil conductivity testing and information. Typically the cold climate approach is to size the loops and geoexchange system for a balanced heating and cooling load profile, and if skewed to more heating that cooling, use more geoexchange tube, and use a supplemental boiler for the peak heating load conditions.

Yes, there are some examples where some well meaning folks have created permafrost, and have lost the use of the system until the ground temperatures recovered (years sometimes), usually as a result of undersized geo fields and poor soil conductivity assumptions.

There are other examples where solar water heating panels are used to "charge" the ground temperature for winter heating - keeps the geo field small, but with the additional expense of the solar panels (more tube or solar panels? Do the math for the project)

Another example of geoexchange for a heating dominated climate is the housing project on Okotoks, Alberta, where all the homes are equipped with solar water heating panels which dump excess heat into a set of closely spaced vertical tube loops to heat up a big chunk of earth, then use that heat all winter without having to rely on an actual water to water heat pump. Drake Landing - weblink:

http://www.dlsc.ca/

 

[AbbyNormal]

they are viabke in Sweden as well

Take the "V" out of HVAC and you are left with a HAC(k) job.