The Geysers geothermal field in California is still the largest producer of geothermal energy in the world.
The development of advanced exploration tools and technologies will accelerate the discovery and utilization of the U.S. Geological Survey's estimated 30,000 MWe of undiscovered hydrothermal resources in the Western United States by increasing exploration and confirmation well success rates. More effective exploration methods address a major barrier to increased geothermal energy production by lowering the high upfront risk and cost of project development. Locating undiscovered geothermal resources will support the near-term expansion of renewable energy because once found, hydrothermal resources can be brought online quickly using current technologies.
What are Hydrothermal Resources?
A geothermal resource requires fluid, heat, and permeability to generate electricity. Conventional hydrothermal resources contain all three components naturally. These geothermal systems can occur in widely diverse geologic settings, sometimes without clear surface manifestations of the underlying resource.
The lack of ability to accurately predict temperature and permeability at depth from the surface is a major cause of exploration risk. Additionally, subsurface characterization and imaging are critical for the efficient utilization of all types of geothermal resources, including low temperature and coproduced, permeable sedimentary and enhanced geothermal systems. The Geothermal Technologies Office is also focused on reducing the operations and maintenance (O&M) costs of hydrothermal systems.
Exploration Research and Development Priorities
The Geothermal Technologies Office conducted a technology needs assessment for geothermal exploration technologies in 2011, identifying areas of opportunity where technology advancements could increase geothermal exploratory success and reduce up-front development risks and costs. The Office focuses R&D efforts in these five categories:
- Improved invasive measurement tools and techniques
- Improved next-generation geophysical airborne data
- Improved non-invasive geophysical techniques and improved data collection for interpretation for existing techniques
- Stress/strain data mapping
- Play Fairway Analysis
- Improved geochemical techniques to estimate reservoir temperatures and processes
- High-resolution remote sensing data and reliable automated processing methods
- Multi-disciplinary conceptual models
- 3-D modeling techniques (software)
- Case study examples of geothermal systems in different settings
- Identification of potential surface signals that identify deeper, hidden systems
Exploration Technology Priorities
- Reduce the high level of exploration risk during the early stages of development
- Increase the economic viability of exploration technologies
- Foster useful data for the National Geothermal Data System