The world is running out of fuel.
Non-renewable energy sources like fossil fuels will one day run out, and when that happens, the world will need new sources of electricity.
However, a new form of green energy may be on the rise. Geothermal electricity is energy derived from the Earth’s inner heat. Very simply, “geothermal” means ‘earth heat’, says the website of CanGEA, the Canadian Geothermal Energy Association.
“On a large scale, the intensity of this thermal energy increases with depth… [because] the temperature of the Earth increases as we travel closer to its centre,” the website said.
The most common example of natural geothermal energy is through natural hot springs, such as those found in Nordic countries.
This extreme heat can be transformed into electricity using two different methods, the flash steam power plant and the binary cycle power plant. Both methods incorporate pumping extremely hot, high pressure, water from the Earth’s inner layers and processing it through a generator to turn it into steam or vapour.
“The pressure created by this steam is channeled through a turbine, which spins to create electrical power,” CanGEA says.
Because the Earth is constantly warm, geothermal energy is 100 per cent renewable and environmentally friendly. However, it does come at a cost, literally.
“Geothermal energy is by far the most expensive, compared to other forms of green energy,” University of Ottawa professor Jean-Thomas Bernard said.
“For Ontario, geothermal energy costs about 25 cents per kilowatt hour (kw/h). Wind power is about 8-9 cents per kilowatt hour and solar energy is 15-16 cents per kilowatt hour. Right now, the cheapest way to produce power is with natural gas, and it costs 5-6 cents per kilowatt hour.”
Why is it so costly? The drilling process to produce geothermal electricity is highly expensive, and drilling costs increase exponentially with depth.
“To produce electricity, you must drill at least 500 to 1000 m down,” Bernard said. “At this time, that kind of power is just too costly for most consumers.”
The good news is that the future looks bright for geothermal electricity. Currently, drilling technology is advanced enough to harness energy as close to the Earth’s crust as possible, CanGEA’s website said.
Because of the way Earth’s heat is distributed and the shifting of tectonic plates, geothermal electricity production is most feasible for countries that surround the Pacific Ring of Fire. High tectonic plate activity allows for large amounts of heat to rise to the Earth’s surface, which provide perfect conditions for geothermal electricity production. Countries like Japan, the Philippines, Mexico and the United States have started to take advantage of their geothermal resources to produce energy.
Another positive aspect of geothermal electricity is the lack of health problems associated with it; geothermal power is entirely safe and environmentally friendly.
“At this time, I don’t believe there are any health risks with geothermal electricity,” Bernard says.
“But, from an economic perspective, it just isn’t within our range right now. Perhaps in the future.”
