Geothermal Energy in Colorado

Paul MorganColorado Geological Survey

for the

Colorado Rural Electric AssociationEnergy Innovations Summit 2013

October 28, 2013, Denver, Colorado

Geothermal: Earth-heatDirect Use – direct use of Earth’s heat as

heatSpas, greenhouse heating, district heating…

Geosource Heat Pumps – Earth is used as thermal mass for heating and/or cooling

Power generation – convert Earth’s heat into another form of energy, usually electricity

Direct Use Under-Developed in Colorado

Americulture: Animas Valley New MexicoMain product: Tilapia fingerlings

Eurofresh: Willcox ArizonaMain product: Gourmet tomatoes & other salad vegetables

The Greenest MW is the MW not generated

Power GenerationAlthough other schemes have been suggested, geothermal power is currently produced by using geothermal heat to vaporize a fluid which drives a turbine which rotates a generator

The simplest system uses dry steam

Dry steam is rare

Binary Power Plant

Most newer systems are binary power plants

Soda Lake II, Nevada, 12 MW

Chena Hot Springs, Alaska, 400 kW Binary Water-Cooled Geothermal Power Plant

Source: Chena Hot Springs Resort

Environmental Benefits of Binary Geothermal Systems

• No emissions:– No NOx, SO2, COx, particulate matter, etc.

• Minimal water use with air-cooled or direct water-cooled plants

• No impact on water quality• Minimal land use:

– Subsidence and seismicity mitigated by reinjection

– Can be made to blend in with surroundings

Geothermal Energy in Colorado

>50°C/km or>2.7°F/100 ft

Colorado Interpretive Geothermal Gradient Map

Concluding Remarks• Three basic flavors of geothermal use:

– Direct-use: Long history in Colorado, but under-developed in terms of full potential

• Heat pumps:– Potential just being recognized: domestic, state,

retail buildings; the no-brainer clean energy solution

• Geothermal power generation:– Colorado’s new frontier – first deep wells will

probably be drilled in 2014

THANK YOU Acknowledgements:

This work benefitted from conversations and corrections from many colleagues in the Colorado Geological Survey, the Division of Water Resources, the Governor’s Energy Office, and Pioneer natural Resources. Matt Sares, Hal Macartney, Francisco Flores and Kevin Rein have been particularly helpful. Partial funding has been received in contracts from the Department of Energy through the Colorado Governor’s Energy Office and the National Geothermal Database System Project through the Arizona Geological Survey.

For Further Information http://geosurvey.state.co.us/

Energy ResourcesGeothermal

Paul Morgan tel: 303 384 2648 e-mail: morgan@mines.edu