Geothermal energy advantages and disadvantages.

Pros and Cons of Geothermal Energy

Geothermal energy, a marvel of our natural world, offers a unique blend of advantages and disadvantages that are worth examining. Here in this article, I am going to take a closer look at some of the major pros and cons of geothermal energy. 

Geothermal energy, derived from the Earth’s core, presents a compelling case as a sustainable and eco-friendly energy source. It is considered to be a key element in future energy supply based on renewable sources. Due to several advantages of geothermal energy this energy source has become one of the most talked about and promising alternative energy sources. I have come across many people wanting to know about the basic geothermal energy facts and its benefits. Therefore, before we dive into the major geothermal energy advantages and disadvantages, let’s start by understanding what geothermal energy is and how does geothermal energy work.

What is Geothermal Energy?

Geothermal energy is defined as, the energy that emanates from the heat in the core of the earth. ‘Geothermal’ literally means ‘Earth’s heat, which is estimated to be 5,500 degrees centigrade at the Earth’s core – about as hot as the surface of the sun. Geothermal energy is a clean, renewable resource, harnessable in regions with favorable geological conditions.

How does geothermal energy work?

The earth’s core which lies almost 4,000 miles beneath its surface is so hot that it boasts molten temperatures. The heat from the earth’s core radiates outwards and heats up the outer layers of rock called the ‘mantle’. When rocks in the Earth’s crust and upper mantle reach extremely high temperatures, they become molten rock, known as ‘Magma’. The temperature of magma usually falls somewhere between 700 and 1300 degrees Celsius. Magma (molten rock) may sometimes come quite close to the surface of the earth transferring heat to groundwater trapped in porous rocks or water flowing along fractured rock surfaces and fault lines.  This interaction beneath the Earth’s surface creates a usable form of geothermal energy.

Some of this super-heated water eventually rises to the Earth’s surface, manifesting as hot springs, geysers, and steam vents. Sometimes the hot water becomes trapped below the surface as a geothermal reservoir. By drilling boreholes into these geothermal reservoirs the hot water and steam are piped up which can then be used directly to heat our homes, generating electricity, and more. Various countries have developed diverse methods to tap into these geothermal energy sources.

The Pros and cons of geothermal energy

While there are many pros of geothermal energy, either directly or indirectly, it also comes with its share of disadvantages.

Below is a short overview of some of the most important pros and cons of geothermal energy. The pros of geothermal energy listed below are based on the utilization of the energy source in two main ways – for generating Electricity and for heating and cooling purposes.

It would be evident from the list of geothermal energy advantages and disadvantages given below, that the advantages of geothermal energy greatly outweigh its disadvantages, especially when compared with fossil fuels.

Pros of geothermal energy 

Eco Friendly

One of the most compelling advantages of geothermal energy is its minimal environmental impact. Unlike fossil fuel alternatives such as coal, oil, and gas, most geothermal systems release only water vapor, with minor emissions of sulfur dioxide, nitrous oxides, and particulates. Geothermal power plants have a negligible carbon footprint, making them nearly 100% emission-free.

However, there are a few polluting aspects of geothermal energy which are mentioned below but they are minor compared to the pollution associated with coal power and fossil fuels.

Renewable Energy source

Another major advantage of geothermal in the list of geothermal energy advantages and disadvantages is that it is a sustainable and renewable energy resource as long as the Earth exists. Now, why is geothermal energy considered a renewable resource?

The Earth is continuously radiating heat out from its core. The constant flow of heat from the earth’s core ensures an inexhaustible and essentially limitless supply of energy for billions of years to come. Once the hot water or steam, trapped below the surface of the earth in the geothermal reservoirs is utilized, it can be reinjected into the ground. This renewable nature sets geothermal energy apart from conventional sources like coal and fossil fuels, which will eventually deplete.

Stable and Predictable supply

Unlike solar and wind power geothermal power is a reliable source of supply as it is available all year long and we can predict the power output of a geothermal plant with remarkable accuracy. Geothermal power plants can operate at near-maximum capacity for 365 days a year, providing a reliable energy supply.

Solar panels can only produce electricity during the day and wind turbines only produce power when there is enough wind. But one of the major advantages of geothermal energy is that it can constantly produce electricity and the energy supply is non-fluctuating. The benefit of constant supply makes geothermal-based power plants excellent for meeting the base-load energy demand.

Direct Usage

Geothermal energy systems are adaptable to many different conditions. Apart from generating electricity, the hot water from geothermal reservoirs can be directly used for heating or cooling homes and businesses efficiently, to grow crops, dehydrate foods, warm fish ponds, melt ice on roads and sidewalks, or for other multiple purposes. The direct use of geothermal energy can be done by the usage of geothermal springs for the purpose of heating, and melting sidewalks during winter. Today geothermal heat pumps are used in about 45 states in the US and around the world, to heat and cool homes, buildings, and businesses.

This direct use of geothermal energy offers flexibility and efficiency and is one of the major advantages in the list of geothermal energy advantages and disadvantages.

Lesser land requirement

Another major pros of geothermal energy is that the land required to build a geothermal facility is much less compared to all the power-generating technologies in use today. A geothermal power plant needs about 1.4 square miles of land to produce one GigaWatt of electrical power while coal facilities require 12 square miles of land and wind farms need 4.6 square miles to yield the same amount of power.

Cost-effective

Electricity generated by geothermal plants is considered to be one of the most cost-effective sources available today. While initial construction costs, including exploration and well drilling, are substantial, ongoing operational costs are remarkably low.  Geothermal power stations do not require fuel for power generation, resulting in energy that is up to 80% cheaper than conventional fossil fuel plants.  This is one of the major pros in the list of pros and cons of geothermal energy. Homeowners typically achieve energy savings of up to 25% to 50% over conventional systems of cooling and heating by using geothermal energy.

Huge potential

The huge potential of geothermal energy is also one of the major pros in the list of geothermal energy pros and cons.

Geothermal energy’s potential is enormous and continues to grow globally. As of January 2016, the global market of geothermal power is at about 13,300 MW of operating capacity spread across 24 countries, and based on current data, the global geothermal industry is expected to reach more than 20,000 MW by next 5 to 7 years. Despite geographical limitations and initial costs, geothermal energy holds substantial promise as a future primary energy source. A recent study by the Geothermal Energy Association (GEA) estimated that just 6.5% of global geothermal energy potential, has been tapped so far.

You may also like to read this related post: Geothermal cooling – how does geothermal cooling work

Cons of geothermal energy

High upfront cost

The biggest disadvantage of geothermal energy in the list of geothermal energy advantages and disadvantages is its high initial costs. Significant expenses are incurred in surveying suitable locations and drilling geothermal resources. Geothermal power plant construction and well drilling currently cost about $2-5 million per MW of electricity generated.

Geothermal energy is currently being harnessed in a small number of countries of the world. The main reason for this is that geothermal power plants are currently economically viable primarily in areas near tectonic plate boundaries. However, the recent technological advances should significantly expand the range of viable geothermal resources in years to come.

Location-specific Source

Another major drawback of geothermal energy production is that you just can’t set up a geothermal power station anywhere you want. It requires specific geological conditions. This energy source is only suitable for regions with hot rocks beneath the Earth’s surface, capable of producing hot water and steam consistently. Rock strength also matters a lot because some rocks are too strong to drill through. These rocks must also occur at reasonable depths to make drilling down to them a feasible option. A suitable location for drilling should be positioned near an area with adequate water availability since geothermal energy extraction demands a substantial water supply.

Possibility of Local Depletion

Although geothermal energy is considered a sustainable and renewable energy source and the geothermal sites are capable of providing heat for many decades, eventually specific locations may get out of steam as a result of low temperature or due to over-hydration which is injected to cool off the rocks, rendering the site incapable of generating sufficient energy. This is one of the major cons of geothermal in the list of pros and cons of geothermal Energy. Extensive initial research is, therefore, needed for selecting the proper site before setting up the geothermal plant  to avoid such local depletion of geothermal resources.

 Environmental Concerns

Another downside of this energy source in the list of geothermal energy pros and cons is that the geothermal plants can release small amounts of greenhouse gases such as hydrogen sulfide and carbon dioxide. Additionally, the water in the underground reservoirs may also contain traces of toxic elements like arsenic, mercury, and selenium, which can potentially impact water sources if the geothermal system is not adequately insulated.

Frequently asked questions

Before I conclude let me also address some of the questions often asked by people related to pros and cons of geothermal energy.

What are the major negative effects of geothermal energy?

Air and water pollution are two leading environmental issues associated with geothermal energy technology. Other concerns are the safe disposal of hazardous waste, land subsidence, and requirement of a large amount of water by geothermal power plants for cooling or other purposes.

What are the main uses of geothermal energy?

Geothermal energy can be used in different ways depending on the resource and technology chosen. 3 main uses of geothermal energy are heating and cooling buildings through geothermal heat pumps, generating electricity through geothermal power plants, and heating structures through its direct-use

Is geothermal energy safe?

Geothermal energy is safe when extracted from the right location and properly used. Geothermal energy, or “earth heat”, can be used as hot springs for warmth and cleansing.

How long can geothermal energy last?

Geothermal heat pumps last significantly longer than conventional equipment. They typically last around 25 years.

You might also like to read this related post: Is Geothermal Energy renewable or nonrenewable?

 Conclusion

Upon careful examination of the pros and cons of geothermal energy described in the post it becomes evident that this energy source offers remarkable advantages over extremely polluting and unsustainable fossil fuels. But it also suffers from a few disadvantages mentioned above, which is why it is not being utilized everywhere to its full capability.

While it may not be feasible everywhere, taking given examples of major countries like the US, Philippines, Indonesia, Mexico, New Zealand, Italy, Iceland, Kenya, and Japan, which have had great success with this source of energy, one can highly recommend putting more focus on harnessing this Earth-friendly resource in a safe and cost-effective manner.