Geothermal Energy Production
Geothermal energy production provides a highly efficient and stable source of heat and power with limited environmental impact (small footprint and low emissions). Waste heat from energy production provides an opportunity for economic growth in other sectors and most importantly, provides independence and sustainable farming opportunities in remote communities.
- GEO: Earth
- THERMAL: Heat
Production of geothermal energy involves using the heat from the Earth to provide heat and electricity for our use at the surface.
Geothermal heat is created by:
- the radioactive decay of naturally occurring Uranium, Thorium and Potassium in the rocks of the Earth’s crust (83%)
- by conduction of heat from the Earth’s molten core (17%).
There is presently enough heat energy stored in the crust of the Earth to last us almost 10 million years!
Although residential-scale heating is a form of geothermal energy (called geo-exchange), geothermal energy is commonly used at a much larger scale to generate electricity that can power communities or industrial use.
Unlike drilling for petroleum resources (which deplete over time), a properly managed geothermal system can sustain itself indefinitely without the need to drill more wells.
how do we access this heat?
At tectonic plate boundaries, where magma approaches the surface:
- Rift Zones
- Subduction Zones
The Earth has an average geothermal gradient of 25°C per kilometre - which means that the temperature increases 25°C every kilometre we travel into the Earth. Nearer to plate boundaries, the geothermal gradient is much higher (and nearer to the continental interior, the geothermal gradient is much lower). Generally, we aim to drill in areas of high geothermal gradient (so we can access the highest heat at the shallowest depths).
Canada is the only country located on the Pacific Ring of Fire that does not presently use geothermal energy for power production.
It is generally accepted that this is because nationally, we have indulged in our relatively abundant and therefore cheap petroleum resources.
global geothermal energy use:
Geothermal energy is used to generate power in 24 countries worldwide:
Although Canada has not yet developed its geothermal resources for power generation, North American contributes 35% of the global geothermal power production (which totals 12,635 MW).
- The United States are the #1 producers of geothermal energy in the world, yet it only accounts for 0.03% of national electricity production!
- In the Philippines, geothermal energy accounts for 27% of electricity.
- In Kenya, geothermal energy accounts for 51% of electricity!
Direct Heat Use
The Earth's heat can be (and is being) used directly to provide:
- Space heating & cooling
- Industrial drying & processing
- Greenhouse food production
- Soil reclamation
- Snow melting
- Bathing & swimming
Geothermal resources that are >80°C can generate power
- Hot water from depth turns to steam
- Steam drives a turbine to create electricity in a binary or flash power plant.
roadblocks to geothermal energy production
In Canada today, geothermal energy is not used to create electricity. One reason is that there are limited sales markets. Our utilities are distributed by Crown Corporations who must administer power purchase agreements if electricity is to be contributed by private entities.
Also, we have established almost 100 years of policy evolution in the petroleum industry. Provinces with limited petroleum reserves have utilized rivers and streams to access hydroelectric power. It is natural that there would be resistance to change from these well-established systems.
As petroleum reserves are dwindling and we are consuming at a rate that is no longer practically served by our hydroelectric systems, it is difficult to access alternative energy sources within our existing political framework. This results in a prolonged regulatory process and complicated leasing and permitting practices.
It is generally accepted that developing geothermal resources requires a high degree of upfront capital. Given that Kenya is the #1 per capita producer of geothermal energy (whilst being on the lower end of the list of national per capita GDP), we might imply that the upfront capital cost is relative to other available resource options. In Canada, there are financing options available in the petroleum, mining and wind energy industries, which create tax incentives for the investor and do not apply to other industries.
To make changes to our present government policy, people need to understand and advocate for their energy options.
canadian geothermal energy association
CanGEA has created an automatic form that sends a letter on your behalf to your elected officials. The letter advocates for geothermal energy's potential and encourages policy changes that will allow for its development. All you have to do is fill out your name, email address and postal code!