Geothermal Energy

Description:

  • Geothermal energy is heat energy generated and stored in the Earth. Geothermal energy is produced by the radioactive decay of materials within the Earth. Due to the geothermal gradient of the Earths core and surface, a continuous conduction of thermal energy is formed
  • Geothermal energy has been used since the Paleolithic times in the form of hot springs
  • It is now used to generate electricity and district heating, space heating, spas, industrial processes, desalination and agricultural applications

Green Energy:

  • “Free Energy”
    • Geothermal energy is essential a free source of energy for us as it is produced naturally by the Earth
    • It is reliable environmentally friendly, sustainable, and cost-effective
  • Environmentally Friendly
    • Although geothermal energy isn’t as clean as other forms of renewable energy, like solar or wind, it is still much cleaner than the non-renewable alternatives
    • Geothermal wells do release greenhouse gases, but the emissions they produce are much lower than those of other fuel sources like fossil fuels

Canadian Perspective:

  • Location and Costs
    • Canada’s geothermal energy is most abundant in British Colombia, Alberta, and Saskatchewan. Geothermal energy is one of the most affordable forms of electricity generation over its life span, but Canada does not see much geothermal production due to the initial start up costs
    • In British Colombia, there is an abundance of cheap and clean hydropower from long-running generating stations. This is not true for Saskatchewan, as they are looking for new sources of energy to compete against their fossil fuel source
    • Saskatchewan now has plans to construct Canada’s first geothermal plant which is planned to have 5 MW in capacity
  • Struggles
    • Geothermal energy mining is risky as the upfront capital costs are high and approximately 20% of mining excavations are unsuccessful
    • When Ontario decided to implement the feed-in tariff program (FIT) for alternative energy, geothermal was not on the list

Technology Advancement:

  • Geothermal energy has traditionally only been available in select areas around the Earth due its accessibility being limited to areas near tectonic plate boundaries. Recently this has started to change thanks to technological advancements
  • Geothermal Piping Systems
    • Geothermal piping faces issues such as changing elevations, uneven terrain, seismic and thermal movement
    • Standard outdoor piping is connected by welding two pipes together, this is not reasonable for situations in which there is a lot of thermal expansion and contraction of pipes
    • Engineers developed a new grooved mechanical pipe joint which consists of four elements: grooved-end pipe, a gasket, coupling housing, and nuts and bolts
    • The new method consists of the coupling housing encasing the gasket and engages the grooves around the circumference of the pipe to create a leak-tight seal
  • Excess Carbon Dioxide to Electricity
    • Geothermal wells release CO2 which is undesirable, but researchers are considering a way to reuse this excess to their benefit
    • The multifluid design will enable geothermal power plants to store energy away – perhaps hundreds of gigawatt hours – for days or even months, so that it is available when the electricity grid needs it. The underground geothermal formation could store hot, pressurized CO2 and nitrogen, and release the heat to the surface power plant when electricity demand is greatest. The plant could also suspend heat extraction from the subsurface during times of low power demand, or when there is already a surplus of renewable power on the grid.