Colorado's Potential

Seeing as our school is located in Golden, Colorado, it only makes sense that my geothermal energy class is doing a course project on the geothermal potential of the state of Colorado.  We are considering the five most promising areas in the state: the Glenwood Springs area, the Mt. Princeton area, the Denver Basin, an area of southwest Colorado including Pagosa Springs and Durango, and lastly, the Raton Basin.

I received a comment last week which made me think that the public regards geothermal energy as impractical for Colorado.  This is untrue, which leads me to think that the public is just largely uninformed on this matter.  I can relate; I had never really heard of the existence of viable geothermal resources in Colorado until I started taking this class, and really analyzing the potential here.  In fact, Colorado is the second most endowed state in the country when it comes to geothermal resources.  If you have Google Earth, check this U.S. Geothermal Resource Map out.  It'll give you an idea of where the best resources are throughout the country.

Most of us Coloradans have heard of or visited the hot springs pools in Glenwood Springs and Pagosa Springs, These are only two areas which show promise for utilization of hydrothermal waters in Colorado, and actually aren't even the hottest spots despite their popularity (see geothermal gradient map below).

Most of the locations in Colorado aren't hot enough to be considered for electrical generation, but there are plenty of areas that could greatly benefit from direct use (using the resource for greenhouses, aquaculture, and heating buildings), which in the case of space heating could probably completely .

However, there are a few sites where electrical generation could be a viable opportunity.  The hottest spot in Colorado is considered to be the area surrounding Mt. Princeton (outlined in the above map).  Based on geochemical data (dissolved elements in the waters that have been produced thus far), the resource is thought to have a gradient of 100 degrees Celsius per kilometer depth, which is more than enough heat for power generation.  In fact, that kind of gradient is comparable to some of the better geothermal wells in New Zealand which have capacities upwards of 30MW.

Another spot that shows huge potential is an area near the town of Somerset, which is just a small coal mining town near Paonia and Delta.  Only a few holes have been drilled in this area by the coal mine, and to relatively shallow depths, but the heat gradients they recorded were huge (almost as high as in Mt. Princeton).  By extrapolating the data, the Colorado Geologic Society has calculated that the area of the heat anomaly is much larger than near Mt. Princeton though, showing huge promise for future geothermal power generation in the area.  The main problem here is that the anomaly is in a relatively remote area where transfer of power onto the grid would be somewhat difficult.  There is a potential for the coal mine to exploit the reservoir and use the energy to improve the efficiency and "environmental friendliness" of their operation.

The main problem I found when researching the Somerset area, which happens to be a common problem for most of the potential geothermal areas in Colorado is the general lack of data.  There are plenty of shallow drill holes with great data near Somerset, but no deep drill data which is what we really need to assess the potential in the area.  So, like Dr. Simmons said in my interview with him, what Colorado really needs to progress the geothermal energy industry is more R&D, more exploration, and deeper drill holes!