Guideline for electricity generation from hot springs (natural energy storage systems): A techno-enviro-economic assessment

The scattered hot springs on the globe are natural thermal energy storages that are available for industrial and recreational advantages. A hot spring is a hydrothermal system that can be used for power generation purposes as well as deep-well geothermal plants. Harnessing energy from hot springs is a practical approach for a future with sustainable power supply. Therefore, there is a demand for a comprehensive study for the estimation of power generation capacity of hot springs based on their mass flow rate and temperature. A techno-enviro-economic study is conducted to estimate the power generation capacity of hot springs as a heat source of the organic Rankine cycle. The organic Rankine cycle plant is modeled and simulated for various temperatures and mass flow rates of hot springs in the present study. The impacts of the temperature and mass flow rate of hot springs on the technical and economic aspects of the power generation plants are investigated. For the hot springs with temperature and discharge mass flow rate from 60 to 90 degrees C and 5 to 50 kg/s, respectively, the power generation capacity alters from 9.3 kW to 303 kW and the levelized energy cost is from 0.02 $/kWh to 0.11 $/kWh. The results indicate that the hot springs with a higher temperature and discharge mass flow rate have a higher thermal efficiency and power generation capacity for the organic Rankine cycle plant while payback period, levelized energy cost, and specific investment cost shrink. The hot springs with higher temperatures and/or larger discharge mass flow rates are financially ideal candidates for initiating the power generation plants.