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Geothermal power underused

Our modern world requires a lot of energy, much of which is not apparent. For example, a smart phone requires 0.25 GJ of energy to produce (along with a variety of precious metals, petroleum and an amazing amount of water). Given there are 1.
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Our modern world requires a lot of energy, much of which is not apparent.

For example, a smart phone requires 0.25 GJ of energy to produce (along with a variety of precious metals, petroleum and an amazing amount of water). Given there are 1.9 billion phones produced per year and they typically have a two year lifespan, the annual amount of energy spent on smartphones is comparable to the amount of energy put into building cars.

We don't see this energy because it is imbedded in the production of the product. In the case of a smartphone, charging it might take 4 kW over an entire year, and so we think they are not very energy intensive. But use of a smartphone amounts to just a few per cent of the total embedded energy.

As we go forward, where is all this energy going to come from?

Presently, the vast bulk of the energy we use comes from fossil fuels and biofuels. About 91.4 per cent of the world's energy production involves the generation of large quantities of carbon dioxide.

Of the remaining 8.6 per cent, nuclear power dominates at 4.8 per cent followed by hydro at 2.4 per cent. All of the other energy sources amount to 1.4 per cent.

Switching energy horses - from carbon dioxide producing sources to renewables - is going to take a considerable amount of time, ingenuity and effort. But we do know how to do it if we choose to.

One source of relatively clean, but under-exploited, energy is geothermal. The province of British Columbia has significant geothermal capacity and yet we use very little. Indeed, geothermal energy has essentially been locked out of the Canadian marketplace with the exception of heat pumps for homes and buildings.

But using geothermal energy is not new as it dates back thousands of years. In the city of Bath, England, the Romans took advantage of natural hot springs to not only heat their water, but also provide indoor heating to the local community. Heating rooms by laying warm water piping under floor tiles is very ancient technology.

Various communities over the intervening time have taken advantage of naturally occurring hot water to heat buildings and create spas. In British Columbia, the Rocky Mountains feature several resorts such as Fairmont, Radium, and Liard River which take advantage of natural geothermal activity. However, we don't tend to use these natural sources of heat for district heating projects.

Perhaps more importantly, we don't use our geothermal resources to generate electricity.

The process isn't particularly complicated. It doesn't require leaps of ingenuity or dazzling feats of engineering. Indeed, 30 countries around the world - including the United States - have significant geothermal electrical capacity. The biggest site south of the border are the Geysers in California.

New Zealand gets a significant amount of its electrical energy from geothermal sources, as do the Philippines and Indonesia. All of these countries take advantage of their position on the "ring of fire" surrounding the Pacific plate. B.C. is part of that ring.

To produce electricity, water is pumped into the ground and heated by internal energy to form high pressure, high temperature steam. When the water returns to the surface, the steam can drive a turbine in much the same way it does at a typical gas or coal powered plant. That is really all there is to it - water goes into the ground, gets turned to steam, returns to the surface, drives a turbine and cools to water which can be pumped back into the ground.

In the case of the Geysers in California, for the first 30 years or so of operations, they didn't even need to pump the water back into the ground as there was a natural aquifer from which they could draw their water/steam.

Modern geothermal plants are being designed, though, to add one more layer of complexity. On average, across the surface of the Earth, the crust heats up about 30 degrees for every kilometre of depth. This means if you want to tap geothermal energy in the middle of a tectonic plate, you would need to drill a bore hole six kilometres deep. (Near a plate's edge or in regions such as the Rocky Mountain trench, bore holes don't need to be anywhere near as deep.)

New plants are taking advantage of much cooler water - as low as 57 degrees - by adding a secondary loop in which a low boiling liquid is warmed by the water.

This liquid generates a "steam" or gas which then drives the turbines. In these plants, a bore hole two kilometres in depth is useable. This represents a significant decrease in the cost and risks associated.

We need energy not tied to carbon dioxide production. Geothermal could be used to our advantage. Indeed, the community of Valemount is ideally situated to do just that.