Volcanic Geothermal Energy : Between an Energy Dream and Technical Realities

Yet, behind this enticing vision lie technical, environmental, and economic challenges. Can volcanic energy truly contribute to the energy transition ?

Raw Power, Yet Underutilized

Magma, the scorching heart of volcanoes, heats rocks and groundwater to extreme temperatures. This thermal energy powers geysers, hot springs, and potentially even power plants.

Some countries have recognized the value of this resource. Iceland, a pioneer in this field, uses geothermal energy to heat over 90% of its homes and generate a significant portion of its electricity. These successes demonstrate that volcanic energy is more than just a scientific curiosity : it is a stable, low-CO2 energy solution compared to fossil fuels.

Nevertheless, this resource remains largely underutilized on a global scale. This is due not only to the complexity of the required infrastructure but also to the rarity of suitable geographical zones. Only certain regions possess the ideal geological conditions for its exploitation.

Consistent Electricity Production

In favorable areas, technological solutions already harness this natural and constant heat. These systems can be divided into three categories, depending on their ability to adapt to different geological and thermal contexts.

• Dry steam : Naturally emitted steam from volcanic soils is captured to drive turbines. Simple and effective, this method is, however, limited to regions where geological conditions produce sufficient steam, such as the geothermal fields of Larderello in Italy.

• Hot water systems : Water heated by volcanic rocks is pumped, converted into high-pressure steam, and then used to generate electricity. This method, widely used in regions such as Indonesia and the Philippines, is particularly suited to geothermal zones with significant aquifer activity.

• Binary cycle : Hot water is used to heat a secondary fluid with a lower boiling point than water. This fluid vaporizes and drives a turbine to produce electricity. Due to its flexibility, this type of installation is expected to dominate future geothermal plants, particularly in regions with moderate temperatures.

Natural, Financial, and Environmental Constraints

While these technologies offer consistent electricity production, unlike wind or solar energy, they still face limitations and must overcome various challenges.

• Geological risks : Active volcanoes are often in unstable regions prone to earthquakes and eruptions. These conditions make securing infrastructure particularly challenging.

• Economic barriers : Initial costs are high. Drilling to access underground heat reservoirs requires sophisticated equipment and significant investments. Added to this are maintenance costs to ensure the longevity of the installations.

• Environmental impacts : While generally clean, volcanic geothermal energy can release harmful gases such as hydrogen sulfide and cause microseism

Local Successes, Limited Global Potential

Some countries leverage their geological conditions to efficiently exploit this resource. Beyond Iceland, Kenya, New Zealand, and Japan also use geothermal energy to varying degrees. In the United States, The Geysers in California is the world’s largest geothermal facility.

However, these examples remain isolated. Exploitable volcanoes are rare, and their geographical distribution limits the global application of this technology. Moreover, the output of geothermal power plants often declines over time, as evidenced by The Geysers.

The Future of Volcanic Energy

The future of volcanic energy may lie in technological innovations. Ultra-deep drilling, which can access hotter layers, opens up new possibilities. Hybrid systems combining geothermal and solar energy or the use of more efficient fluids could enhance its effectiveness. However, these advancements require massive investments and international cooperation. Developing countries, often rich in geothermal potential, frequently lack the resources to fully exploit this energy.

In summary, volcanic energy is far from being a universal solution. In suitable regions, it can become an important pillar of the energy transition. But on a global scale, it can only be one tool among many to address the challenges of climate change.

More information : https://www.creos-net.lu/