Harnessing geothermal energy in Kazakhstan: Techno-economic assessment of Organic Rankine Cycle application in the Almaty region

This study assesses the feasibility of geothermal electricity generation in Kazakhstan using Organic Rankine Cycle (ORC) systems to exploit low- to medium-temperature geothermal resources. ORC systems efficiently convert heat from moderate-temperature sources into electricity using organic fluids with boiling points lower than that of water. Globally, ORC systems contribute over 3 GW of installed capacity, accounting for 25.1% of geothermal power production. Kazakhstan’s electricity generation rose from 85.3 TWh in 2013 to 98.4 TWh in 2023, with associated CO₂ emissions increasing from 67.4 to 77.0 million tonnes. Despite known geothermal reserves, the country has not yet developed geothermal power capacity. This study identifies the geothermal potential of the Mangystau-Ustyurt and Almaty Artesian basins, with a focus on the Zharkent field. Among the wells evaluated, Well 5539, with a wellhead temperature of 103°C, is estimated to generate 5.467 TWh of electricity annually, accounting for 51.9% of the regional potential. Wells 1-RT and 2-TP also show strong promise, with annual outputs of 2.471 and 2.598 TWh, respectively. Thermal power availability ranges from 5.1 to 8.3 MW, and the combined yearly potential of 10.5 TWh could offset 82.1% of the Almaty region’s electricity deficit and avoid 5.47 million tonnes of CO₂ emissions annually. The methodology includes thermodynamic modelling and well data analysis to estimate geothermal electricity potential. This study represents the first assessment of ORC-based geothermal power in Kazakhstan for low-temperature wells in a specific region.