Geothermal energy is a renewable energy source! This is because it’s a source with almost an unlimited amount of heat generated by the Earth’s core. It is not a nonrenewable source of energy because it can be re-used without being truly depleted!
Geothermal energy is a renewable energy source because it generates unlimited thermal power from the Earth’s core. Geothermal produces electricity without depletion, so it is not a nonrenewable energy source. The Earth’s core generates an unlimited amount of heat, and even if we were for some reason to have a huge spike in the energy that is harvested, there is still enough that we most likely would never have to fear running out. This is also true because this renewable energy source is also regenerated over time. While in some cases, the rate of regeneration is slower than in others, geothermal energy has proven that it will be around for a long while. Similar to the solar energy that is produced from the sun, geothermal energy is the heat that is produced from the Earth. There is no shortage of this heat, and we have only just begun to scratch the surface on its uses.
During the planet’s formation, Earth generated and maintained a huge amount of heat energy, which is why geothermal gas is a renewable energy source. In addition to this, the decay of radioactive elements within the Earth has also been producing heat. The amount of heat energy that the Earth produces is much more than the amount of energy we use when utilizing geothermal energy. That said, at any specific geothermal field, the temperature of the energy reservoir may be decreased over time as fluids are extracted. Produced fluids can actually be re-integrated to maintain pressures, but this may further cool down the reservoir if not completed properly. Over time, it will be necessary to drill more wells to maintain energy production.
The above-mentioned issues can cause the status of geothermal energy (renewable or non-renewable) to be debatable. In regions such as Iceland and New Zealand, shallow hotspots where the Earth’s molten core comes to the surface are utilized to extract geothermal energy. While these spots may vary, utilizing the heat they produce does not deplete them.
Some geothermal energy is gathered from wells of around 5 km in depth below granite veins. Granite is weakly radioactive, and the rocks soak up a ton of heat, making them very hot. The heat that granite produces can be extracted by putting down two wells, fracturing rock between them, and pumping water down one well to acquire steam from the other. This system depletes the heat source because it is generated over millions of years and does not regenerate as fast as we use it. After the wells have been depleted, the well essentially runs dry, and it would be time to find another heat source. Even though the Earth and Sun will eventually run out of energy (over millions of years), the energy that they produce is considered infinite.
Why is Geothermal Energy Considered a Renewable Resource?
Generally speaking, for an energy source to be considered renewable, three points of criterium should be met.
- Is the source of energy naturally powered by nature?
- Will the source of energy eventually be depleted?
- After extracted and used, does the energy source replenish?
As you can guess, renewable energy should be powered by nature, the source of energy cannot be depleted, and it is replenishable. Applying these three points of criteria, we can indeed establish that geothermal energy is renewable. For instance:
- Is the source of energy [geothermal] provided by nature? Considering it is from the heat generated by the earth, then the answer is yes.
- Will the source of energy [geothermal] eventually run out? No, it will not.
- Is the source of energy [geothermal] naturally replenished by nature? Yes, as we established above, it is naturally replenished.
When the three criteria have been established, you can see that geothermal energy is by all accounts renewable. However, it should be noted that nothing is in black and white as with anything in life. Although geothermal energy is clearly a renewable energy source, several pros and cons should be considered when using geothermal energy.
Just because something is considered renewable does not mean that it is a clear solution to the planet’s energy needs. With our growing population, there is a trend for people to automatically think that one particular energy source will solve all of our energy needs. That is not the case, and there is no telling what the future holds or if this is a viable energy source for years to come.
Real-Life Examples of Geothermal Energy
Some power plants can use hot steam from naturally formed vents in the Earth to power generators that create electricity used to power our civilization. In the vicinity of a lake, coils can be placed at the lake’s bottom to unfreeze the added water in these coils to maintain the appropriate temperature. This water can then be used to heat buildings or greenhouses. As you may have guessed, hot springs provide direct heat applications.
7 Facts About Geothermal Energy
- Studies on energy efficiency have found that geothermal energy is the most environmentally friendly heating and cooling system currently available.
- Geothermal energy is stored within the Earth.
- The word “geothermal” is derived from the Greek words ‘Earth’ (geo) and heat ‘thermos.’
- The technology behind geothermal energy has made leaps and bounds in progress but still only provides for a fraction of the Earth’s electricity generation.
- As of 2014, 24 countries utilize geothermal electricity generation for power, while 70 countries use it for heating and cooling.
- Although it may not have been realized, our civilization has benefited from geothermal energy for thousands of years in the form of hot springs.
- Industrial pumps, space heating, heat pumps, and hot springs are all forms of geothermal energy.
How a Residential Geothermal Heat Pump Uses Renewable Energy
The design of a geothermal heat pump is pretty simple: by using ground loops buried 10 feet or deeper below the frost line, there is access to a steady flow of heat emanating from the Earth. With a mixture of water and anti-freeze inside the loops, heat is absorbed and sent to the heat pump indoors. It can also remove indoor heat and deposit it to the ground; in this process, any heat used can be immediately replaced by the heat from the Earth’s core. Although you will still need electricity to power this heat pump, it is far less than with other types of heating pumps.
Using a geothermal heat pump, you are helping to decrease our dependence on fossil fuels like coal, gas, and oil. Geothermal systems also produce fewer emissions, so it is a great choice for your budget, as well as the Earth.
Where is Renewable Geothermal Energy Available?
Geothermal energy is available from hydrothermal resources or reservoirs of steam or hot water. These are available primarily in the western region of the United States, Alaska, and Hawaii. However, the energy can be tapped into and utilized almost anywhere with geothermal pumps. Further down the road, as the technology advances, we may expect to see other resources for geothermal energy utilized, such as hot, dry rock and magma.
What Are the Environmental Impacts of Using Geothermal Energy?
There are no real environmental disadvantages to using geothermal gas, other than the sludges (production of sold materials) that some plants can produce, which generally require disposal. However, some of these solid byproducts are now being extracted for sale, making the resource even more valuable and a boon to our economy.
There are plenty of advantages to using geothermal energy, and emissions are low. The geothermal flash plants emit only excess steam and vapors. There are no harmful emissions that these plants discharge. Dissolved materials and salts present in geothermal fluids are generally reintroduced into the geothermal reservoir at a depth that is well below groundwater aquifers; this is safe for the environment and replenishes the supply that is found in the reservoir.
What is the Visual Impact of Geothermal Technologies?
There is almost no visual impact of integrating district heating systems and geothermal heating pumps into communities. Geothermal power plants are relatively small and don’t require the storage, transportation, or combustion of fuels that other power plants require. There are little to no visible emissions from these power plants, and what is visible is not harmful to the environment. For these reasons, there is generally no negative visual impact resulting from developing new geothermal power plants, even in scenic regions.
Is it Possible to Deplete Geothermal energy Reservoirs before it is Renewed?
Geothermal energy production has been shown to have long-term sustainability, as demonstrated at the Lardarello field in Italy (1913), the Wairakei field in New Zealand (1958), and the Geysers field in California (1960). These demonstration sites are still up and running and fully producing geothermal energy. For any power plant to be currently producing after that many years shows how sustainable geothermal energy can be, even though pressure and production declines have been apparent at some plants, and operators have begun to reinject water to maintain reservoir pressure.
In Santa Rosa, California, pipes treated wastewater up to The Geysers to be used as reinjection fluid, which prolonged the life of the reservoir while recycling the treated wastewater.
How Much Does Geothermal Energy Cost Per Kilowatt Hour?
For example, at The Geysers, power is sold at $0.03 to $0.035 per kWh. If a power plant that generated electricity from geothermal energy were to be built hypothetically, it would probably need around $0.05 per kWh. Some power plants do charge more during energy-intensive times of the year.
What are the Different Types of Geothermal Power Plants?
There are currently three types of geothermal power plants that use different technologies to convert geothermal energy into electricity. These power plants are dry steam, flash steam, and binary cycle. The type of method used is selected during development and varies depending on the fluid, steam or water, and temperature.