Geothermal energy is a form of sustainable energy originating from the thermal energy within the Earth's crust.
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Geothermal energy is produced using the Earth's natural heat within its crust. This is typically accomplished by drilling deep into the ground to access hot water or steam reservoirs.
Geothermal energy is widely regarded as a sustainable and environmentally friendly energy source due to its minimal greenhouse gas emissions and comparably small ecological impact in contrast to traditional fossil fuels.
Production of Geothermal Energy
Geothermal energy is generated by harnessing the thermal energy within the Earth's interior via a complex series of steps. Geothermal resources are identified and investigated through geological surveys, temperature readings, and other indicators of geothermal activity.
Following identifying a feasible resource, drilling wells into the Earth's crust is initiated to gain access to the reservoirs of hot water or steam. Subsequently, the hot water or steam is extracted via production wells and conveyed to the surface.
Geothermal power plants utilize the extracted hot water or steam to generate electricity. They are classified into dry steam, flash steam, and binary cycle plants.
Dry steam power plants
Dry steam power plants utilize steam to power turbines for electricity generation.
Flash steam plants
Flash steam plants release high-pressure hot water from a reservoir into a lower-pressure tank, resulting in the water rapidly transforming into steam.
The steam is subsequently utilized to power turbines.
Binary cycle plants
Binary cycle plants use high-temperature water or steam to elevate the temperature of a distinct working fluid with a lower boiling point, such as ammonia or isobutane. The fluid in question undergoes a phase change from liquid to vapor, which subsequently powers turbines that facilitate the production of electrical energy.
Advantages of Geothermal Energy
Geothermal energy presents various benefits as a sustainable energy alternative. The Earth's internal heat is a dependable and constant energy source that is virtually inexhaustible and accessible at all times. This stands in contrast to solar and wind energy, which are contingent upon weather patterns and, therefore, less reliable.
Geothermal power plants exhibit high capacity factors, indicating their ability to sustain operation at a significant proportion of their maximum capacity over an extended period, ensuring a reliable and uninterrupted electricity supply.
Geothermal energy is considered an environmentally sustainable energy source due to its minimal contribution to greenhouse gas emissions. Geothermal energy is distinct from fossil fuels in that it does not involve the combustion of any fuels, mitigating air pollution and avoiding any contribution to climate change.
Geothermal energy exhibits a wide range of potential applications beyond electricity generation. Geothermal heat pumps or district heating systems can provide heating and cooling services for residential, commercial, and industrial applications.
Utilizing geothermal energy yields economic advantages by generating employment opportunities within the geothermal sector, bolstering regional economies, and mitigating reliance on imported fossil fuels. Geothermal resources are frequently situated in geographically isolated or sparsely populated regions, presenting an opportunity for enhanced economic growth and revenue generation via geothermal initiatives.
Geothermal energy is renewable and powerful. Why is most of it untapped?
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Current Limitations in the Usage of Geothermal Energy
Geothermal energy utilization is constrained by various limitations that impede its extensive adoption. A constraint that needs to be considered is the restricted accessibility of geothermal resources based on the site's location.
The feasibility of geothermal energy utilization is contingent upon the existence of subterranean hot water or steam reservoirs, constraining its accessibility in certain geographical locations. The exploration and drilling of geothermal resources pose significant challenges and expenses, necessitating specialized expertise and equipment.
Geothermal energy development is constrained by the considerable initial expenses involved. Developing geothermal energy infrastructure, such as deep wells, power plants, and transmission lines, can require significant capital investment. This may present financial obstacles, particularly for smaller-scale geothermal initiatives or in areas with restricted financial means.
Geothermal energy development may encounter obstacles in the form of regulatory and permitting issues, as it necessitates adherence to environmental regulations, land use policies, and community involvement. Acquiring permits and approvals for geothermal projects can be intricate and lengthy, contributing to project development's overall expenses and duration.
Despite these constraints, geothermal energy is a propitious form of sustainable energy with numerous advantages. The complete utilization of geothermal energy for a sustainable and cleaner future can be achieved through continuous technological advancements, policy support, and increased investment, thereby surmounting the current limitations.
Recent Developments in Geothermal Energy
In recent years, there have been notable advancements and developments in geothermal energy, contributing to its growth and potential as a renewable energy source.
Drilling technology progress, including directional drilling and enhanced geothermal systems (EGS), has broadened the scope of geothermal energy generation to encompass regions with atypical geothermal resources or lower-temperature reservoirs.
A noteworthy advancement pertains to the escalating utilization of geothermal heat pumps, alternatively referred to as ground source heat pumps, in the context of edifices' heating and cooling.
The aforementioned systems exhibit high efficiency and can furnish heating and cooling remedies for a wide range of buildings, including residential, commercial, and industrial structures. This, in turn, mitigates the dependence on non-renewable energy sources for HVAC systems.
Policy support has been instrumental in the recent advancements made in geothermal energy. The deployment of geothermal projects has been facilitated by implementing regulatory frameworks, financial incentives, and feed-in tariffs by governments and policymakers in different countries. This has resulted in increased investment and research in geothermal energy development.
In addition, the utilization of geothermal energy is progressively penetrating novel markets and applications that extend beyond the production of electricity. These include direct employment for heating and cooling in agriculture, aquaculture, and industrial procedures, broadening its applications and possibilities.
The recent advancements in geothermal energy have been partly attributed to international collaborations and partnerships between countries, which have facilitated knowledge sharing, technology transfer, and joint research and development initiatives. The collaboration on a global scale has expedited the progress of geothermal technologies and their implementation in various geographical areas.
European Plan to Substitute Natural Gas with Geothermal Energy
Europe aims to promote using geothermal energy as a replacement for natural gas.
The European Union (EU) has set ambitious goals to reduce greenhouse gas emissions and transition to renewable energy sources, and geothermal energy is considered a promising option. The EU sees geothermal energy as a viable alternative to natural gas for heating and cooling buildings and industrial processes.
The EU has outlined plans to support geothermal energy development, including funding research and innovation, improving regulatory frameworks, and promoting investment in geothermal projects.
WeHEAT Closed-Cycle Geothermal Heat System
The WeHEAT closed-cycle geothermal methodology employs a binary cycle approach, wherein a secondary working fluid transfers heat from the geothermal reservoir to the power plant. This process circumvents the direct extraction of geothermal fluid.
Utilizing a closed-cycle approach in geothermal power generation results in enhanced efficiency and environmental sustainability. This is achieved by mitigating the hazards associated with brine extraction and reinjection and curtailing the discharge of greenhouse gases.
The technology, developed by MS Energy Solutions, has garnered recognition for its inventive and eco-friendly attributes, having been bestowed with awards in the "Climate & Environment" and "Technology" classifications during the "Highlights of Hungary" event.
Future of Geothermal Energy
Geothermal energy exhibits a promising outlook for the future due to its numerous advantages. It is a sustainable and renewable energy source that accesses the thermal energy stored within the Earth's crust, offering a dependable and uninterrupted supply of environmentally friendly energy.
This renders it a compelling alternative for decreasing greenhouse gas emissions and alleviating climate change. Geothermal energy exhibits minimal greenhouse gas emissions, rendering it ecologically sustainable and harmonious with worldwide decarbonization objectives.
Geothermal energy exhibits versatility and flexibility. The versatility of this technology allows for its utilization in diverse contexts, such as power generation, thermal regulation, and refrigeration, rendering it amenable to a range of domains, including but not limited to residential, commercial, and industrial sectors.
Geothermal energy also provides various socioeconomic advantages. Geothermal power can generate employment opportunities at the regional level, encompassing drilling, construction, and operation of power plants, fostering economic expansion and bolstering energy stability. In addition, it is worth noting that geothermal resources are frequently situated near centers of demand, diminishing the necessity for energy transmission over long distances and heightening energy efficiency.
References and Further Reading
Zayed, M. E., Shboul, B., Yin, H., Zhao, J., & Zayed, A. A. (2023). Recent advances in geothermal energy reservoirs modeling: Challenges and potential of thermo-fluid integrated models for reservoir heat extraction and geothermal energy piles design. Journal of Energy Storage, 62, 106835. https://www.sciencedirect.com/science/article/abs/pii/S2352152X23002323
Xu, Y., Li, Z., Tao, M., Jalilinasrabady, S., Wang, J., Li, G., & Zhong, K. (2023). An investigation into the effect of water injection parameters on the synergetic mining of geothermal energy in mines. Journal of Cleaner Production, 382, 135256. https://www.sciencedirect.com/science/article/abs/pii/S0959652622048302
McClean, A., & Pedersen, O. W. (2023). The role of regulation in geothermal energy in the UK. Energy Policy, 173, 113378. https://www.sciencedirect.com/science/article/pii/S0301421522005973