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Geothermal a viable alternative to nuclear or coal-fired options

Geothermal is defined as: relating to or produced by the heat in the interior of Earth.

Geothermal is defined as: relating to or produced by the heat in the interior of Earth.

Geothermal heating, or ground heat, can be used for the space heating of your home, or as in the case of countries like Philippines, the U.S. and Italy, among others, for generating steam to drive the turbines that make electricity.

Geothermal is not a new concept — it has been around since the first hot spring was used for warming a cold human in 300 BC. It is in only the past few decades that the technology has been made available for the average home owner to make use of it.

I am not going to get too technical here; suffice it to say that the machinery and installation vary considerably depending on the make and design.

The basic theory of a geothermal installation involves a heating medium, usually propylene glycol, being circulated through a system of piping buried in the ground or set into a water well.

The heating medium picks up heat from the ground or water in the well and through the magic of the heat pump, delivers that heat into the home, where it is distributed to keep the family warm.

In reality, though, a heat pump is not a magical device — anyone who has a refrigerator knows that heat can be moved from one area to another to serve our needs and purposes.

A heat pump also has the ability to remove heat from the house and put it back into the ground, enabling summer cooling.

In the off-grid home, a geothermal system for heating is not a valid answer. Yes, the heat generated does replace the gas used by a furnace or boiler, but the extra amount of electrical-producing equipment needed to power the heat pump is not economical.

Extra insulation in the attic and walls on initial construction would be more cost effective than the burying of lines or drilling a well.

If you are connected to the grid, geothermal can be very cost-effective, depending on your location and particulars of home construction.

If your electrical supply is supplemented with a grid-tied photovoltaic array, or wind turbine, then the benefit to the environment and reduction in home operation costs together would be significant.

For green power on a massive scale, geothermal electrical plants rival hydroelectric.

Italy for example has had geothermal production in the Lardarello field since 1913.

Iceland has the natural resources of superheated aquifers that only need to be tapped into.

The type of geothermal system that would be used here would see wells drilled to depths of 4,000 or 6,000 metres that would have water pumped down one well and returned as superheated steam up another.

Geothermal is a viable alternative to nuclear or coal-fired generation stations. Will we see it in Alberta in the next little while? Not likely, but down the road, all options will have to be considered and this is an exceedingly good one.

Lorne Oja is an energy consultant, power engineer and a partner in a company that installs solar panels, wind turbines and energy control products in Central Alberta. He built his first off-grid home in 2003 and is in the planning stage for his second. His column appears every second Friday in the Advocate. Contact him at: lorne@solartechnical.ca