Southern Methodist University’s Geothermal Laboratory recently released a map that proves once again how much potential energy is locked beneath America. SMU’s resource map, which took years to develop with funding from Google.org, shows that there are enough technically recoverable resources throughout the U.S. to equal 10 times the amount of coal capacity in place today.
Other maps have shown similar data. Last year, SMU issued a map (also funded by Google) that showed massive geothermal potential under West Virginia, an area not typically seen as suitable for the technology. In 2007, MIT Researcher Jeff Tester analyzed deep “hot rock” resources, showing that the U.S has 100 GW of potential for Enhanced Geothermal Systems [EGS] — an emerging type of plant design in which a developer creates an artificial well by pumping water through deep rocks, rather than using direct steam from hot water reservoirs closer to the surface.
So big deal, right? Another map shows we have tons of resources. Why is this so different from the others?
Well, geothermal exploration can be a very risky business. It’s not uncommon for a developer to spend 3/5ths of capital on the exploration and drilling phase of a project. And if the resources aren’t there, that’s millions of dollars down the…bore hole.
This map and corresponding study gives the geothermal industry another great tool for evaluating resources, particularly in areas on the East Coast where developers haven’t ventured. SMU provides an explanation (and a good video of EGS starring Energy Secretary Steven Chu):
In this newest SMU estimate of resource potential, researchers used additional temperature data and in-depth geological analysis for the resulting heat flow maps to create the updated temperature-at-depth maps from 3.5 kilometers to 9.5 kilometers (11,500 to 31,000 feet).
This update revealed that some conditions in the eastern two-thirds of the U.S. are actually hotter than some areas in the western portion of the country, an area long-recognized for heat-producing tectonic activity. In determining the potential for geothermal production, the new SMU study considers the practical considerations of drilling, and limits the analysis to the heat available in the top 6.5 km (21,500 ft.) of crust for predicting megawatts of available power.
This approach incorporates a newly proposed international standard for estimating geothermal resource potential that considers added practical limitations of development, such as the inaccessibility of large urban areas and national parks. Known as the ‘technical potential’ value, it assumes producers tap only 14 percent of the ‘theoretical potential’ of stored geothermal heat in the U.S., using currently available technology.
In other words, this assessment, which shows we have enough recoverable resources to overtake our coal capacity ten times over, is pretty realistic.
Google.org funded this detailed piece of research as part of its suite of strategic investments in geothermal R&D and project deployment. But even with these resources and the high-profile backing from companies like Google, the pace of development in the geothermal industry will still be moderate.
That’s because developers in the sector are competing with oil and gas companies for drilling rigs and workers. Securing capital for projects from the still-tight financial markets has also been tough for companies. And in next-generation EGS, drilling technologies and power plant designs are still in pre-commercial phase. This isn’t an industry that can deploy projects very rapidly.
Even with some constraints, it’s clear that the Americans are blessed with an enormous amount of technically-exploitable resources under our feet. And no, it’s not coal, oil or natural gas.
Here’s a good video of Enhanced Geothermal Systems (and it beats the heck out of gas fracking):
- Geothermal energy is a core climate solution: Five hot, rockin’ geothermal companies
- Geothermal: “The US Geological Survey estimates the US could generate 150,000 megawatts.”
- Heat Pumps: The ‘other’ geothermal