What Is the History of Geothermal Power?

Looking into geothermal power history often focuses on the global developments in the field starting in the second half of the 20th century. This can make it seem like a recent technology, but the use of geothermal energy goes back a lot farther than most people think.

Humanity has been harnessing geothermal energy for hot water since the Stone Age. The Roman Empire utilized it further for the heating of homes from the 1st century, and by the 14th century, there was infrastructure in place to use geothermal energy for entire districts. The first electricity generated from geothermal power was in 1904. The global spread of this type of power began in 1958.

Geothermal power goes back in time quite far, and some would even argue that it is among the first sources of energy that people used. In the rest of the article, we are going to do a deep dive into these tens of thousands of years of history to learn how we got to geothermal power as we know it today.

Was Geothermal Energy Used Before Electricity?

The overwhelming majority of geothermal power history predates its use for generating electricity, the invention of commercial electricity, and even written history itself. Following the 1992 Symposium on the History of Geothermal Energy, which was held in Mexico City, a team of researchers set out to investigate the role of geothermal power as the ancients would have used it.

Because nothing from prehistory was recorded and the writings from the historical record gave little practical information on geothermal energy due to the writers’ poor understanding of it, the investigation was not straightforward. Nonetheless, by also examining sources that were written from a more esoteric perspective, the researchers could make significant progress in understanding how these ancestors used geothermal energy.

Hot Water

The most basic way to harness geothermal energy is to use hot water from springs. This practice dates back to as early as the Paleolithic, so during these times, the hot water would primarily be used for the direct benefit of the individual involved.

Since most of us are used to hot showers, it should not be surprising to learn that our ancient ancestors preferred bathing in hot water rather than cold rivers and lakes. Although hot springs were not as ubiquitous as ordinary water sources, where they did exist and were discovered, they were favored for this purpose.

The hot springs also provided a way for people to stay warm during winter months or colder nights. A person could submerge themselves in the water for warmth or even just stay close to it to benefit from the heat that it was radiating.

The hot water from these springs provided a source of heat that could be used to cook foods. Although fire was usually preferable, these springs would be convenient for when it was too difficult to light a fire due to a lack of resources or environmental conditions. The springs also provided a convenient way to boil food for times when that was the preferred cooking method.

Finally, many hydrothermal products that were created by geothermal energy and found in the springs were used throughout humanity’s history with these sites as health products.

Industry

Geothermal energy was also very valuable to the ancients for industry. A lot of byproducts of the processes were used in a number of different tasks, including ceramics, glassmaking, textiles, and construction.

Because of the immense amount of energy that is involved in it, geothermal power gave the people of the ancient world an incredible advantage that they would not be able to replicate by simply lighting a fire.

Heating of Buildings

The Romans were known for heating homes and other buildings through the use of hypocausts. These were systems that would transfer hot air through compartments below floors and sometimes through walls as well to heat higher levels. Most hypocausts and all early ones used furnaces to burn fuel to create the heat.

These furnace-powered hypocausts were extremely expensive to maintain. Not only did they need a constant supply of high quantities of fuel in order to keep the furnace going and power enough to heat multiple rooms, but they also required a lot of labor to keep the furnace fed and cleared.

In areas where there were hot springs, however, the Romans would harness this geothermal energy to heat the homes and other buildings of the area. Using geothermal power for the hypocausts instead of furnaces allowed them to operate with almost no material input and very little labor. This improved not only the comfort of the people who lived in those homes, but also their health and quality of life.

The Romans are often remembered for using geothermal energy to power public baths, but fewer people are aware of the extent that they used it in other aspects of their infrastructure, like heating.

Heating Infrastructure

Although the Romans laid the foundations for using geothermal power for heating buildings, the scale of their projects was limited and these systems went out of use as the authority of the Romans receded from those areas. Starting in the 14th century, almost a full millennium after the Western Roman Empire’s fall, the concept was revisited and at an even larger scale.

The commune of Chaudes-Aigues is famous for both the high temperatures and number of its hot water springs. These were known to the Romans, as evidenced by their writings, and were likely utilized during the time of the Roman Empire. In the 14th century, the commune once again began tapping into this source of geothermal energy for the purpose of space heating.

Although it started out small, the heating infrastructure of Chaudes-Aigues was the precursor to all of the similar systems that developed around the globe in the following centuries. The current district heating of the commune is a direct continuation of the original 14th century infrastructure.

When Was Geothermal Energy Used for Electricity?

The first use of geothermal energy to produce electricity happened in 1904 in Larderello, Italy. This first test was unimpressive and inefficient compared to how geothermal power had been used in the past, but it was nonetheless a very important proof of concept for how this source of energy could be used to generate electricity.

Adoption of geothermal power plants across the world was initially very slow, but it has been picking up at an exponential rate, and this is likely to continue.

Italy and Humble Beginnings

On July 4, 1904, either four or five lightbulbs, depending on the source, produced light while being powered by a turbine that itself was powered by the steam from the same naturally occurring vents in Larderello that had been known about since Roman times.

On its own, this demonstration could serve little practical purpose, but it did provide a working prototype of a fully geothermally powered turbine that could generate electricity. This technology was developed further over the following seven years, and in 1911, Larderello’s geothermal power plant became fully operational.

Japan and the United States of America did experiment with geothermal power generation on a small scale over the following decades, but Italy remained the only producer of geothermal power on a meaningful scale until 1958.

Global Proliferation

The Wairakei Power Station within the Taupo Volcanic Zone in New Zealand became the first full geothermal power plant outside of Italy when it began operations in 1958.

This kickstarted not only use from other countries, but also interest in technological developments of geothermal power generation. These technologies very notably included ones that allowed the turbines to be able to operate with lower temperature steam, which made geothermal power plants more geographically accessible.

As of 2020, geothermal power is responsible for 1.3% of the world’s total generation of electricity from renewable energy sources. In that year, just under 95,000 GWh of electricity was generated by geothermal power plants.

What Are the Benefits of Geothermal Power?

Geothermal power offers many benefits over other sources of energy. It is touted as clean, renewable, and reliable, but what does this mean in practical terms?

Clean

Geothermal power plants do not release significant quantities of pollutants into the environment. This makes them a good long-term solution to electricity generation since they do not create problems that will be exceedingly difficult to deal with down the line.

Renewable

Geothermal power plants do not need to be manually supplied by fuel from a distant source which is then consumed and needs to be replaced. Although every power plant of that size will need materials and labor to operate, the actual energy source in geothermal plants is already coming from below it and continues to do so whether it is harnessed or not.

Until the very structure of the planet changes in the distant future, there are no concerns for this source of energy running out in any way, therefore making geothermal power fully renewable in all practical terms.

Reliable

The renewability of geothermal power can be considered a sort of long term reliability, but geothermal is also exceptionally reliable in the short term.

Power plants that use fossil fuels are vulnerable to price changes in commodities, infrastructural issues that create problems in logistics, and changing dynamics of markets that operate on a global scale. Geothermal power plants are immune to all of these because they are built over the energy source they use.

Geothermal is also more reliable than other sources of renewable energy. For example, unlike solar power, it still generates electricity when it is overcast or nighttime, and unlike wind power, it continues to work regardless of the weather conditions of the given moment.

What Are the Challenges with Geothermal Power?

Geothermal power is not perfect. Even aside from controversial reports that suggest that noted drops in steam at some sites of electrical generation may mean that the power plants themselves are using up the energy in a way that is depleting it, there are other challenges that are universally accepted.

Expensive

Geothermal power plants are expensive to build. Although they cost less to operate due to there being no need for a constant import of fuel for them, the way the machinery needs to be installed means that there is a very high up-front cost.

In times of energy crisis, even though that should be the ideal opportunity for geothermal power plants to be set up in theory, in practice, the high cost makes it difficult to make the transition in precisely those economic conditions.

Geographically Limited

A region simply wanting to make use of geothermal power is not enough to begin the transition. Generating electricity by harnessing geothermal energy is only possible in a set number of sites where the geology of the planet is suitable for it.

Unlike fossil fuels, which can be imported from anywhere else in the world, the capacity to harness geothermal energy at any given location is down to luck, and if the site is not already lucky, it never will be.

What Is the Future of Geothermal Power?

The future of geothermal power is likely to be a direct continuation of its history. The explosive increase in rate of adoption will probably continue for areas where it is possible, and geothermal’s share of the renewable energy market will increase.

As the technology improves, these types of power plants will also continue to become cheaper and cheaper to build. The more affordable set-up costs will make geothermal power a less daunting alternative to transition to as energy prices rise.

From its humble origins in the stone age to barely more than a century of advancement since it was first used to generate electricity, it is very possible that geothermal power will eventually become one of the most prominent sources of electricity on the planet.

Final Thoughts

Looking at geothermal power history is a journey that stretches very far back and has many milestones. We have learned today about all of the ways in which geothermal energy has been harnessed, from simple use of hot water to fully-fledged power plants, and from this, we get a pretty good picture of where it will go.