In the quest for sustainable and renewable energy sources, geothermal power stands out as a reliable and eco-friendly solution. By tapping into the Earth’s internal heat, geothermal power plants generate electricity with minimal environmental impact, offering a stable alternative to fossil fuels and playing a crucial role in reducing global carbon emissions.
Geothermal energy originates from the Earth’s core, where temperatures can reach up to 5,700°C (10,300°F). This immense heat is a result of residual energy from the planet’s formation and the continuous decay of radioactive isotopes. As heat moves towards the Earth’s surface, it can be harnessed to generate electricity.
Geothermal power plants utilize this heat by drilling wells into geothermal reservoirs to access steam or hot water. This thermal energy is then used to drive turbines connected to electricity generators. Unlike solar or wind energy, geothermal power provides a constant energy output, unaffected by weather conditions, making it a dependable source of baseload power.
Types of Geothermal Power Plants
There are three primary types of geothermal power plants:
- Dry Steam Plants: These are the oldest types of geothermal power plants, directly utilizing geothermal steam to turn turbines.
- Flash Steam Plants: These plants pull deep, high-pressure hot water into lower-pressure tanks, causing the water to rapidly vaporize, or “flash,” into steam to drive turbines.
- Binary Cycle Power Plants: In these plants, geothermal water is used to heat a secondary fluid with a lower boiling point than water. The secondary fluid vaporizes and drives the turbines. This method allows for the utilization of lower temperature resources and is more environmentally friendly, as it prevents the release of geothermal fluids into the environment.
Geothermal energy has been successfully implemented in various parts of the world, contributing significantly to the energy mix of several countries.
Iceland: A prime example of geothermal energy utilization, Iceland sources about 25% of its electricity and 90% of its heating needs from geothermal energy. The Hellisheiði Power Station, located near Reykjavik, is one of the largest geothermal power plants globally, with a capacity of 303 MW of electricity and 400 MW of thermal energy. This facility not only provides power and heating but also contributes to carbon capture initiatives, turning CO₂ emissions into solid minerals through the CarbFix project.
Indonesia: In February 2025, Ormat Technologies, in collaboration with PT Medco Power Indonesia, launched the 35 MW Ijen geothermal power plant in East Java. This facility utilizes Ormat’s proprietary Energy Converter technology to generate low-carbon electricity, contributing to Indonesia’s goal of adding 7.2 GW of geothermal capacity by 2035.
Canada: Geothermal developments in Canada are advancing with DEEP Earth Energy and SLB’s collaboration to create the nation’s first next-generation geothermal project in southeast Saskatchewan. After completing the feasibility phase, the project is set to generate approximately 30 MW of clean, baseload power once the first two phases are completed, marking a major milestone for geothermal energy in Canada.
Geothermal power plants have a relatively low environmental impact compared to fossil fuel-based power generation. They emit minimal greenhouse gases, with life-cycle emissions averaging 45 kg of CO₂ equivalent per megawatt-hour of electricity produced, compared to 1,001 kg for coal-fired power plants. Additionally, geothermal plants have a small land footprint and consume less water than conventional power plants.
Despite its advantages, geothermal energy faces challenges such as high initial capital costs, geographical limitations, and potential environmental concerns like induced seismicity and land subsidence. However, advancements in drilling technologies and enhanced geothermal systems (EGS) are expanding the potential for geothermal energy extraction, making it a more viable option in regions without natural geothermal reservoirs.
Innovations like InnerSpace’s ‘GeoMap Asia’ tool are also aiding in identifying underutilized geothermal resources, promoting their development as reliable and cost-effective energy sources.
Conclusion
Geothermal energy presents a promising path toward a sustainable and low-carbon future. By harnessing the Earth’s internal heat, we can generate reliable and eco-friendly power, contributing significantly to global efforts in combating climate change and reducing dependence on fossil fuels.
