Geothermal energy is the heat that comes from the sub-surface of the earth. It is contained in the rocks and fluids beneath the earth's crust and can be found as far down to the earth's hot molten rock, magma.
Ground source heat pumps and direct use geothermal technologies serve heating and cooling applications, while deep and enhanced geothermal technologies generally take advantage of a much deeper, higher temperature geothermal resource to generate electricity.
Geothermal energy is heat derived within the sub-surface of the earth. Water and/or steam carry the geothermal energy to the Earth's surface. Depending on its characteristics, geothermal energy can be used for heating and cooling purposes or be harnessed to generate clean electricity.
Enhanced geothermal systems, which require energy to drill and pump water into hot rock reservoirs, have life-cycle global warming emission of approximately 0.2 pounds of carbon dioxide equivalent per kilowatt-hour [11].
There are three types of geothermal power plants: dry steam, flash steam, and binary cycle.
Ocean Thermal Energy Conversion (OTEC) is a process that can produce electricity by using the temperature difference between deep cold ocean water and warm tropical surface waters. OTEC plants pump large quantities of deep cold seawater and surface seawater to run a power cycle and produce electricity.
A few steps that can be taken to ensure little or no geothermal pollution are using less electricity, reduce temperature and volume of discharge, storing and reusing heated water, and discharging the wastes in less vulnerable zones.
Geothermal Energy Pros and Cons
| Pros | Cons |
|---|
| Efficient (300- 500% compared to 90% of the best furnaces). | Electricity is still needed to operate heat pumps. |
| Geothermal energy is a renewable resource as long as the Earth exists. | Geothermal energy using wells requires an incredible usage of water. |
Many U.S. communities and individuals benefit environmentally from using geothermal energy. And geothermal energy resources are domestic resources. Keeping the wealth at home translates to more jobs and a more robust economy.
NOx emissions, especially Nitrogen Oxide (NO) – responsible for lung irritation, coughing, smog formation as well as for water quality deterioration. Sulfur Dioxide (SO2) – causing wheezing, chest tightness, respiratory illness as well as various ecosystem damages, especially acid rains.
Geothermal energy is physically reliable because it is consistent, efficient, and can easily accommodate changes in electricity demand.
Hot water near the earth's surface is piped into buildings for heat. A district heating system provides heat for most of the buildings in Reykjavik, Iceland. Industrial applications of geothermal energy include food dehydration (drying), gold mining, and milk pasteurizing.
A Geyser is an example of Geothermal energy. Hot springs, lava, and fumaroles are natural examples of geothermal energy. Geothermal power is currently more common in homes and businesses, using geothermal heat pumps to control the temperature in the building.
What are the Advantages of Using Geothermal?
- Environmentally Friendly. Geothermal energy is more environmentally friendly than conventional fuel sources such as coal and other fossil fuels.
- Renewable.
- Huge Potential.
- Sustainable / Stable.
- Heating and Cooling.
- Reliable.
- No Fuel Required.
- Rapid Evolution.
Geothermal drilling is also one of the main reasons why world doesn't use more geothermal energy. Less expensive drilling, wider area to harness the resource from and reduced capital costs – these are all the solutions on which global geothermal energy industry should build its future progress.
15 Fun Facts: Geothermal Energy
- The largest hot spring in the world is Frying Pan Lake in New Zealand.
- Today, geothermal energy is used in more than 24 countries around the world.
- Geothermal energy produces 0.03% of the emissions that coal produces and .
- Geothermal energy is more than 2,000 years old and is believed to be first used in China.
1. Geothermal HVAC systems are not considered a renewable technology because they use electricity. Fact: Geothermal HVAC systems use only one unit of electricity to move up to five units of cooling or heating from the earth to a building.
Geothermal energy, one of the most promising among renewable energy sources, has proven to be reliable, clean and safe, and therefore, its use for power production, and heating and cooling is increasing. It is a power source that produces electricity and heat with minimal environmental impact [4] .
