The Hidden Energy Beneath Our Feet: 5 Fascinating Facts About Geothermal

There is a powerful source of clean energy that exists that is not the wind nor the sun. It's the hot molten rocks in the earth's crust, only a few hundred meters beneath our feet.

Geothermal energy, which we see exploding to the surface in the form of geysers and volcanoes, is a source of energy that originates from the decay of radioactive particles in the Earth's core that has melted rocks into magma and formed a long lasting "thermal layer."

Despite not being the most well known renewable energy source, many countries have already started to harness its power. Among them are Iceland, El Salvador, Mexico, Kenya, Costa Rica, Australia, Japan, Indonesia and New Zealand, as well as the west coast of the U.S. and many nations across the Caribbean. It's estimated by the International Energy Agency (IEA) and the U.S. Geological Survey (USGS), that geothermal energy could provide 10% of the world's electricity needs by harnessing just a small fraction of the Earth's geothermal heat.

Here are five interesting facts about geothermal energy that reveal its long history and massive potential.

1. Humans have used geothermal energy for millennia

Long before modern technology, ancient civilizations recognized the benefits of geothermal energy. Hot springs, formed when groundwater is heated by the earth's magma, were used not only for bathing but also for heating homes by cultures all over the world.

Over 10,000 years ago, Paleo-Indians used hot springs as a communal gathering place. In ancient China, hot springs were revered for their therapeutic properties, and were believed to have healing powers that could treat a variety of ailments. The Ancient Romans famously used geothermal water to heat their vast public bathhouses, known as thermae, which were social and communal hubs for relaxation, health, and hygiene.

The modern application of geothermal energy came from a small village in Tuscany, Italy called Larderello in 1904, when an Italian engineer was successful in using the natural steam from the ground below to power ten kilowatts of energy, just enough to power five light bulbs.

Less than a decade later, this original geothermal energy plant is part of a matrix of 30 plants that collectively generate 6 billion KWh of energy which meet more than 30% of the region's energy needs.

Geothermal power plants have long operational lifespans, often lasting over 30 years, making them a truly sustainable energy option.

2. Geothermal plants emit minimal greenhouse gasses

On average, geothermal power plants emit 122 grams of carbon dioxide per kilowatt-hour, which is 73% lower than emissions from natural gas plants and up to 90% lower than coal-fired plants.

Geothermal power plants don't burn fuel, which also reduces the emission of other harmful gasses like sulfur dioxide and nitrogen oxides, making them a truly environmentally friendly alternative to oil, coal and gas.

3. Geothermal energy has been widely used for heating and cooling

Geothermal energy is not only a source of electricity but also a valuable resource for heating and cooling through a system known as geothermal heat pumps, (GHPs). This system utilizes stable underground temperatures, which remain consistent throughout the seasons, allowing it to efficiently exchange heat with the surface environment.

In colder months, GHPs extract heat from the ground and transfer it indoors, providing reliable heating. Conversely, during warmer months, the process is reversed: the heat pump removes heat from the indoor space and releases it into the cooler ground, effectively cooling the building.

This process typically involves a network of pipes that circulate fluid through the ground. By leveraging this geothermal exchange, GHPs can significantly reduce energy consumption-by 25-50%-compared to traditional HVAC systems.

Unlike conventional HVAC systems that rely on combustion or electrical resistance for heating, GHPs use the Earth's natural thermal energy, leading to a significant reduction in greenhouse gas emissions. As the vast majority of the American heating demand comes from fossil fuels, there is room for a potential for a revolution in this market.

4. The U.S. leads the world in geothermal electricity generation

While geothermal only accounts for 0.4% of U.S. electricity currently, America still produces more geothermal power than any other country - nearly 4 gigawatts, enough to power 3 million homes!

The world's largest geothermal field, known as The Geysers, located in California, can produce 1.5 gigawatts via its collection of power plants.

This is just the beginning, as the U.S. government aims to increase geothermal capacity 22-fold by 2050. They are working to rapidly expand the implementation of geothermal power plants and facilities across the country. The Department of Energy has promised to use money allocated for investment in renewable energy to install 28 million GHPs. During the most recent session of Congress, bipartisan legislation known as the Geothermal Energy Optimization (GEO) Act of 2024, aims to expedite the permitting processes and encourage geothermal project leasing on federal lands to accelerate renewable energy production.

5. Is it true geothermal excavation has been connected to earthquakes?

Unfortunately, the development of geothermal energy faces challenges, one of which is the potential for induced seismicity. This phenomenon can occur when water is injected into underground geothermal reservoirs, which may contain either hot water, steam, or a combination of both, to enhance production.

The injection process can increase pressure and alter the geological structure, sometimes leading to minor earthquakes. This risk is particularly relevant in areas where the Earth's crust has existing faults or weaknesses.

Although these earthquakes are generally small in magnitude, they have raised concerns in densely populated areas. However, advancements in technologies and protocols are helping to mitigate these risks, ensuring that geothermal energy remains a safe and viable option for power generation.

In a world hungry for sustainable solutions, geothermal energy is a hot contender! By tapping into the Earth's natural heat, we have the opportunity to revolutionize how we power our lives-reliable, renewable, and right beneath our feet. With innovative technologies and growing enthusiasm worldwide, geothermal energy is not just a future prospect; it's a game changer. So, let's dig deep, embrace this dynamic resource, and ignite a cleaner, brighter energy revolution together!

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