Geothermal energy originates from heat generated by Earth's formation and ongoing radioactive decay, with temperature increasing significantly with depth—a phenomenon known as the geothermal gradient. While the surface remains relatively cool, temperatures rise dramatically underground, creating potential for energy extraction through hot springs, geysers, or deep drilling. High-gradient areas, especially along tectonic plate boundaries like the Ring of Fire, are prime locations for geothermal projects.

Mathematicians and engineers apply specific mathematical methods to explore and optimize geothermal heat for energy production. Lagrangian–Eulerian flow models, named for Joseph Lagrange and Leonhard Euler, characterize fluid movement within geothermal reservoirs, helping understand precipitation, transport, and reservoir behavior critical for extraction efficiency. Stochastic models address system optimization and control under uncertain conditions, while geometric models assist in understanding heat distribution patterns, and they support updating tools like the U.S. Geological Survey's MODFLOW, a three‑dimensional finite‑difference groundwater flow model first published in 1984.

GEOPHIRES v2.0 demonstrates how mathematics integrates technical and economic factors. This open‑source software combines reservoir, wellbore, and surface plant technical models with cost correlations and levelized cost models to estimate capital and operation‑and‑maintenance costs, instantaneous and lifetime energy production, and overall levelized cost of energy for a geothermal plant, enabling developers to assess project viability before major investment.

Once deployed, geothermal plants offer low greenhouse‑gas emissions, negligible fuel costs comparable to wind, and reliable baseload power unlike intermittent sources. However, widespread adoption faces challenges: high initial capital costs for drilling and plant construction, a perception that high‑quality sites are geographically limited, and technical, permitting, and electric‑transmission issues that can inhibit substantial expansion.