Estimating the Geothermal Electricity Generation Potential of Sedimentary Basins Using genGEO (The Generalizable GEOthermal Techno-Economic Simulator)

Abstract

<p><b>Abstract</b></p><p>Sedimentary basins are ubiquitous, naturally porous and permeable, and the geothermal heat in these basins can be extracted with geologic water or CO<sub>2</sub> and used to generate electricity. Despite this, the broad potential that these formations may have for electricity generation is unknown. Here we investigate this potential, which required the creation of the <u>gen</u>eralizable <u>GEO</u>thermal techno-economic simulator (genGEO). genGEO is built with only publicly available data and uses five standalone, but integrated, models that directly simulate all components of geothermal power plants to estimate electricity generation and cost. As a result of this structure, genGEO, or a portion of it, can be applied or extended to study any geothermal power technology. In contrast, the current techno-economic tools for geothermal power plants rely on characterizations of unpublished ASPEN results and are thus not generalizable enough to be applied to sedimentary basin geothermal power plants which use subsurface CO<sub>2</sub>.</p> <p>In this study, we present genGEO as open-source software, validate it with industry data, and compare its estimates to other geothermal techno-economic tools. We then apply genGEO to sedimentary basin geothermal resources and find that using CO<sub>2</sub> as a subsurface heat extraction fluid compared to water decreases the cost of geothermal electricity across most geologic conditions that are representative of sedimentary basins. Using genGEO results and p50 geologic data, we produce supply curves for sedimentary basin geothermal power plants in the U.S., which suggests that there is present-day potential to profitably increase the capacity of geothermal power by ~10% using water as the subsurface heat extraction fluid. More capacity is available at lower cost when CO<sub>2</sub> is used as the subsurface fluid, but realizing this capacity requires geologically storing between ~2 and ~7 MtCO<sub>2</sub>/MW<sub>e</sub>. But developing sedimentary basin resources in the short-term using subsurface water may not eliminate options for CO₂-based power plants in the long-term because the least-cost order of sedimentary basins is not the same for both CO<sub>2</sub> and water. With sufficient geologic CO<sub>2</sub> storage, developing sedimentary basins using CO<sub>2</sub>- and water-based power plants may be able to proceed in parallel.</p>

Thermoeconomic Analysis of Subcritical and Supercritical Isobutane Cycles for Geothermal Power Generation

“…Minor discrepancies can be attributed to the use of different databases for the physical properties of isobutane and different approaches for evaluating pressure drops and heat losses in the piping and heat exchangers. In Nevada (USA), the Tungsten Mountain geothermal power plant [40] uses binary cycle technology with a single Ormat Energy Converter for a nameplate capacity of 37 MW. The geothermal fluid flows from four production wells at a mass flow rate of 4 × 250 kg/s and with a temperature of 142 • C. The average net power output is 24-27 MW, and the parasitic load is 10-15% [40].…”

“…In Nevada (USA), the Tungsten Mountain geothermal power plant [40] uses binary cycle technology with a single Ormat Energy Converter for a nameplate capacity of 37 MW. The geothermal fluid flows from four production wells at a mass flow rate of 4 × 250 kg/s and with a temperature of 142 • C. The average net power output is 24-27 MW, and the parasitic load is 10-15% [40]. The present model puts the maximum net power output at 25.82 MW, obtained with subcritical non-recuperated isobutane and a dry saturated state at the turbine inlet (p 1 = 16.5 bar, T 1 = 90.3 • C).…”

“…The Lazard's annual report [43] estimates the LCOE of geothermal power in the range between 61 and 102 USD/MWh, while Robins et al [45] reports values in the range between 67.5 and 74.0 USD/MWh. The cost data from real geothermal power plants have been found in research articles [40], corporate reports [46,47], and energy news websites [48,49]. Figure 2 shows a comparison between model predictions and the real cost data.…”

Techno-Economic Assessment of Geothermal Resources in the Variscan Basement of the Northern Upper Rhine Graben

“…Compilations of the investment costs of geothermal power plants are provided by various sources (Stefa ´nsson, 2002;Sanyal, 2004;Beckers et al, 2014;Limberger et al, 2014;Schlagermann, 2014;Adams et al, 2021). The cost components described therein are in some cases site-and power plant-specific and therefore not directly applicable for each region.…”

Integrating direct air capture with small modular nuclear reactors: understanding performance, cost, and potential

“…Building upon the development of Climeworks, multiple papers have recently investigated the integration of a solid sorbent DAC with geothermal sources (e.g. [8,13,14]). On the other hand, to the best of our knowledge, only two articles researched the potential synergies between DAC and nuclear fission ( [8,15]).…”