Impact of Well Field Exploration on the Life Cycle Analysis of Geothermal Power Production

Abstract

A model has been developed to represent the exploration stage of geothermal well field development and its materials and fuel impacts on the plant cycle component of the overall life cycle analysis of geothermal power production. The model was developed based on industry input and results from the literature. Included in the model are the drilling of core, slim, and temperature gradient holes as well as confirmation wells. The amount of exploration drilling assumed in the model is compared to recent literature results for Nevada. Due to their very minor contribution, life cycle burdens for the application of geoscience methods employed during exploration surveying are not included in the analysis. Attached to confirmation well drilling is a success rate parameter per well drilled. Specific life cycle burdens addressed include cement, steel (casing), diesel fuel, and water consumption. After adding these material and fuels to those for the entire facility (plant and equipment, operating wells, plant to well piping), their impact on plant cycle greenhouse gas emissions per kWh of geothermal electricity output is discussed. Finally, total life cycle greenhouse gas emissions of geothermal electric power are presented and compared to other power generating technologies.