What Emerging Technologies Will Make Geothermal Energy Source Safer?
Geothermal energy is thermal energy generated and stored in the Earth. It is a renewable source of energy that utilizes the Earth’s natural heat located just beneath the surface or deeper underground. Geothermal energy is considered a clean, sustainable, and environmentally friendly energy source.
Currently, geothermal energy accounts for only about 0.4% of total electricity generation in the United States. In 2020, the U.S. generated 17 billion kilowatthours of electricity from geothermal sources. While geothermal energy has several advantages as a renewable energy source, there are some safety concerns regarding development and usage of geothermal sites. These include the release of hazardous gases during drilling and fluid extraction, induced seismicity from fracturing underground rock, ground subsidence, and the proper disposal of geothermal wastewater.
Enhanced Drilling Techniques
One way geothermal drilling is becoming safer is through enhanced drilling techniques. Companies are developing advanced drilling fluids that are stable at high temperatures, preventing equipment damage and reducing risk of blowouts (TWI Global). Improved drilling equipment like advanced drill bits and casing materials allow for faster drilling and better integrity of the wellbore wall.
New drilling techniques are also emerging, like directional and horizontal drilling, that allow companies to better navigate around geologic hazards and optimize well placement (Technology Review). Directional drilling enables accessing subsurface heat from multiple angles, reducing the number of wells needed. Overall, these enhanced drilling methods are making geothermal drilling more productive and lowering risks.
Enhanced Reservoir Creation
One of the key technologies for enhancing geothermal energy production is improving reservoir creation through advanced stimulation methods like hydraulic fracturing. New techniques are emerging to increase the permeability and porosity of geothermal reservoirs, allowing for greater fluid flow and heat extraction.
Traditional hydraulic fracturing, adapted from oil and gas drilling, involves high-pressure injection of fluids to fracture the reservoir rock. Research is advancing more targeted and controlled methods, like using proppant-gel mixtures, which prop open micro-fractures without inducing large seismic events (CORDIS, 2020). Scientists are also experimenting with alternative techniques like chemical stimulation, which dissolves minerals to enhance permeability, and thermal stimulation involving heating the reservoir to expand fissures (Jia, 2022).
These cutting-edge stimulation methods allow for customized, optimized reservoir creation for each unique geothermal site. Controlled fracturing enhances subsurface permeability and heat flow, while minimizing seismic risks and environmental impacts. Advanced reservoir engineering techniques will be crucial for scaling up geothermal capacity worldwide.
Advanced Resource Mapping
Advanced resource mapping techniques such as seismic imaging and subsurface mapping are enabling geothermal developers to more accurately locate and characterize geothermal resources. Improved seismic imaging utilizes advanced geophysical tools and analysis methods to create high-resolution 3D maps of subsurface geologic structures. This allows for better identification of potential fracture networks and fluid pathways in hot rock formations.
In addition, better subsurface mapping integrates various data sets such as temperature gradients, rock properties, stress fields, and subsurface fluids to build comprehensive geothermal reservoir models. These enhanced reservoir models provide greater certainty about the estimated size and quality of geothermal resources.
By enabling more precise targeting and assessment of geothermal systems, advanced resource mapping techniques can substantially lower exploration risks and costs. This supports accelerated development of geothermal projects while reducing environmental impacts.
Improved Fluid Extraction
Advances in fluid extraction technology are making geothermal energy source more viable and efficient. New pumps and piping allow for the extraction of geothermal fluids from deeper, hotter reservoirs than previously possible. The higher temperatures and pressures at depth necessitate the use of highly durable, corrosion-resistant materials for these components.
In addition, new methods of steam and brine extraction boost the productivity of geothermal wells. Technologies like downhole pumps and advanced well casing designs prevent phase transitions that lead to scaling and corrosion issues during fluid recovery. Purpose-built steam separators and brine reinjection systems also maximize geothermal fluid utilization for energy generation.
Together, these improved extraction technologies and techniques allow more energy to be harnessed from geothermal reservoirs in a sustainable, efficient manner. This makes geothermal a more viable renewable baseload energy source.
Enhanced Energy Conversion
Improving the equipment used to convert geothermal heat into electricity can enhance the overall efficiency and output of geothermal power plants.
One area of innovation is in turbine design. New turbine configurations, such as multi-stage turbines and turbines optimized for binary cycle plants, can enable greater energy extraction. Researchers are also exploring using supercritical CO2 or sCO2 turbines, which are very compact and can achieve high conversion efficiencies. These advanced turbine designs can boost the electrical output from a geothermal resource.
Advances are also being made in heat exchanger technology used in geothermal binary power plants. Improved heat exchanger designs allow better transfer of heat from the geothermal fluid to the working fluid, resulting in increased conversion efficiency. Novel heat exchanger configurations and materials are enabling more effective use of lower temperature geothermal resources. For example, printed circuit heat exchangers with very high surface area density can improve heat transfer rates significantly1.
Together, enhanced turbine and heat exchanger designs enable more electrical power to be generated from a given amount of geothermal heat, improving the viability and output potential of geothermal energy projects.
Better Emissions Control
One of the key ways emerging technologies are making geothermal energy safer is through better emissions control. Geothermal plants produce significantly lower emissions compared to fossil fuel plants, but there is still room for improvement. New innovations allow geothermal plants to reduce their air and water pollution even further.
Advances in scrubbing and filtering techniques are enabling plants to capture a higher percentage of contaminants before they are released into the atmosphere or local waterways. This includes improved filtration systems that use membranes and activated carbon to capture microscopic particles. Additionally, new chemical scrubbing processes can remove harmful gases like hydrogen sulfide more efficiently than traditional methods.
Implementing these upgraded emissions control systems allows geothermal plants to reduce their overall environmental footprint. With less air pollution in surrounding communities and cleaner wastewater being discharged, geothermal energy can become even more sustainable. As these technologies continue improving, geothermal plants will be able to operate with minimal emissions, making them one of the cleanest energy sources available.
Advanced Monitoring
Real-time analytics and control systems are critical for improving safety at geothermal plants. Systems like Mitsubishi Power’s DIASYS Plant Control and Monitoring allow operators to monitor all plant processes in real-time and detect issues early. This enables faster responses to abnormal conditions. Additionally, predictive maintenance features can analyze data to forecast problems before they occur.
Installing more sensors throughout plants provides additional monitoring capabilities. For example, proximity sensors on turbines can detect vibrations and other anomalies, as described by Dewesoft’s turbine monitoring system. This data feeds into the central control platform. Unidata’s systems also monitor geothermal stations by gathering telemetry from wellheads and pipelines. Advanced monitoring maximizes uptime and gives early warning of potential safety issues.
Improved Maintenance
Advancements in preventative maintenance are helping to improve the safety and longevity of geothermal systems. New methods for scale and corrosion prevention, such as advanced water treatment and protective coatings, allow geothermal fluid to flow smoothly through the system (Geothermal Maintenance Checklist). Online condition monitoring using sensors provides real-time data on equipment health and performance. This enables technicians to identify issues early and take preventive action before problems escalate (6 Easy Tips to Handle Geothermal System Maintenance). With proactive maintenance guided by technology, geothermal systems can operate safely and efficiently.
Conclusion
In summary, key technologies making geothermal energy safer include enhanced drilling techniques that reduce seismic activity, improved mapping to identify optimal sites, better emissions controls, and advanced monitoring systems. With continued innovation in these areas, geothermal has the potential to play a major role in the renewable energy mix. According to MIT and Yale research, geothermal is well-positioned to complement intermittent sources like solar and wind. By providing constant baseline power, geothermal can enable higher overall adoption of renewables. NREL predicts rapid growth for geothermal, especially hybrid systems co-located with solar or biomass plants. With the right technologies and policies, the future is bright for safer, cleaner geothermal energy.
