Deep direct-use feasibility study for the Hawthorne Nevada Army Depot and surrounding community

Project lead: Sandia National Laboratories (Dr. Thomas Lowry)

GBCGE project personnel: Dr. Bridget Ayling; Nicholas Hinz

Project collaborators: Navy Geothermal Program Office; Power Engineers

Project duration: 2 years: October 2017 to September 2019.

Total project funding: $560,000

Project goal and accomplishments:  This project aimed to develop a multi-disciplinary, three-tiered analysis approach to assess the geothermal resource and determine the feasibility of implementing a geothermal direct-use facility for the Hawthorne Army Depot (HAD) and the various town and county facilities in Hawthorne, Nevada. The three-tiered analysis approach linked a production side analysis (PSA) and a demand side analysis (DSA) into a whole-system analysis (WSA) to provide an integrated assessment of the resource and the probability of delivering economically viable direct-use energy to the Hawthorne area. In 2019, the conceptual model of one of the blind (hidden) geothermal prospects in the basin was finalized, with two low-temperature resources identified. A deeper resource (~115°C) and a shallower resource (~100°C) are proximal to one another and do not show evidence of mixing, with chemically distinct fluids. A new conceptual model was developed with three probabilistic models that follow a log-normal resource distribution:  P10, P50, and P90.  The P90 model is the most conservative (i.e., a 90 % chance that the proposed model exists in reality, representing the 10th percentile of the cumulative distribution function), the P50 model is the preferred (median) model that is consistent with the available data, and the P10 model is the most optimistic (i.e., a 10 % chance that the proposed model exists, representing the 90th percentile of the cumulative distribution function). Using these models in conjunction with the power density method outlined by Cumming (2016), the deep and shallow systems were estimated to have resource potentials of 7 MWe (P50) and 1.6 MWe (P50), respectively (Ayling and Hinz, 2020). The final results of the project are presented in Lowry et al., 2020.

Geological map showing the location of the three geothermal prospects at Hawthorne, Nevada
Semi-transparent geologic map draped over shaded relief image, and key locations mentioned in the text including the approximate locations of geothermal anomalies informally called prospects A, B and C. Red box corresponds to the map extent of Figures 3, 5, and 12. Faults are represented as dotted black lines. HFZ, Hawthorne fault zone; WRFS, Walker Range-front fault system; WSF, Willow Springs fault. Figure from Ayling and Hinz (2020).

 

Three geological cross sections across the Walker Lake basin, showing the three model scenarios that correspond to P90, P50 and P10 confidence intervals
Cross section B – B’ (south-west to north-east) across prospect A, Hawthorne, Nevada. Interpreted isotherms are in dashed red lines in °C, red arrows indicated interpreted fluid flow directions, and black (solid and dashed) lines represent inferred fault intersections with the cross-section plane. Figure from Ayling and Hinz (2020).

 

Map showing the spatial extents of the shallow and deeper geothermal resources at prospect A at Hawthorne.
P90-50-10 outlines for the deep and shallow resources at Hawthorne prospect A: the deep resource outline was derived from the intersection of the 115 °C isotherm with a 2000 m depth slice, and the shallow resource outline was derived from the intersection of a 90 °C isotherm with a 250 m depth slice. Figure from Ayling and Hinz (2020).

Project publications (listed chronologically):

  • Blake, K., Lowry, T., Lazaro, M., Tiedman, A., Ayling, B. F., Arguello, R., Meade, D. (2017). Hawthorne Army Depot: Update of geothermal exploration and direct use applications, Geothermal Resources Council Transactions, Vol. 41, pp 1031-1041. https://www.geothermal-library.org/index.php?mode=pubs&action=view&record=1033783
  • Sabin, A., Blake, K., Tiedeman, A., Hinz, N., Ayling, B., Lowry, T., Arguello, R., Lazaro, M. (2018). Deep Direct-Use Geothermal: Production Side Analysis from Hawthorne, NV, Geothermal Resources Council Transactions, Vol. 42. https://www.geothermal-library.org/index.php?mode=pubs&action=view&record=1033970
  • Arguello, R., Schwendig, J., Lowry, T., Sabin, A., Blake, K., Lazaro, M., Anderson, S., Ayling, B. F., Tiedeman, A., Hinz, N. H. (2018). Deep Direct-Use Geothermal: Development of a Demand Side Model for the Hawthorne, Nevada Area, Geothermal Resources Council Transactions, Vol.42. https://www.geothermal-library.org/index.php?mode=pubs&action=view&record=1033977
  • Lowry, T.S., Ayling, B., Hinz, N., Sabin, A., Arguello, R., Blake, K., Tiedeman, A., (2020). Deep Direct-Use Geothermal Feasibility Study for Hawthorne NV. Sandia National Lab Technical report SAND2020-3210, https://doi.org/10.2172/1606296
  • Ayling, B.F., and Hinz, N.H., (2020), Developing a conceptual model and power capacity estimates for a low-temperature geothermal prospect with two chemically and thermally distinct reservoir compartments, Hawthorne, Nevada, USA. Geothermics, Vol. 87. https://doi.org/10.1016/j.geothermics.2020.101870
  • Lowry, T., Sabin, A., Ayling, B.F., Hinz, N., Tiedman, A., Arguello, R., Blake, K., (2021). Deep Direct-Use Geothermal: A Probabilistic Systems Analysis Approach for Techno-Economic Analysis. Proceedings, World Geothermal Congress, Reykjavik, Iceland.
  • Ayling, B. F., Hinz, N. H., Blake, K., Sabin, A., Lowry, T., Tiedman, A., (2021). Developing a Conceptual Model of One of Three Geothermal Prospects at Hawthorne, Nevada, USA. Proceedings, World Geothermal Congress, Reykjavik, Iceland.

Previous publications associated with UNR studies at Hawthorne:

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