RT Journal Article
T1 Measurement of Soil Moisture Using Capacitance Measurements: Development of a Low-Cost Device for Environmental and Very-Low-Enthalpy Geothermal Energy Applications
T2 Medición de la humedad del suelo mediante mediciones de capacitancia: Desarrollo de un dispositivo de bajo coste para aplicaciones medioambientales y de energía geotérmica de muy baja entalpía
A1 Pino Fernández, Joaquín del
A1 Martínez Bohórquez, Miguel Ángel
A1 Andújar Márquez, José Manuel
A1 Roca Prieto, Manuel Jesús
A1 Enrique Gómez, Juan M.
K1 Soil moisture measurement
K1 Very-low-enthalpy geothermal energy (VLEGE)
K1 Capacitive sensor
K1 Gravimetric method
K1 Interdigitated electrodes (IDE)
K1 Capacitive sensors conditioning
AB Measuring soil moisture is crucial for optimizing agricultural irrigation, but also, from an energy efficiency standpoint, for the proper design of very-low-enthalpy geothermal energy (VLEGE) facilities. VLEGE represents a renewable energy resource with great potential for residential and industrial applications, as it can provide heating and cooling with high energy efficiency and minimal environmental impact. Soil moisture plays a decisive role in the thermal performance of VLEGE facilities, where small variations in water content can significantly alter the thermal conductivity of the soil and, consequently, the efficiency of their horizontal heat exchangers. This paper presents a low-cost capacitive soil moisture sensor featuring optimized interdigitated electrodes and a controlled dielectric coating that ensures mechanical and electrical stability in subsurface environments. The novelty of this work lies in the validated integration of optimized IDE design, dielectric protection, embedded capacitance acquisition, and gravimetric calibration into a low-cost soil water content measurement device for environmental, agricultural, and VLEGE applications. The developed system converts capacitance variations into direct estimates of soil water content through an integrated microcontroller-based signal-conditioning stage. The developed device is robust, reliable, and readily reproducible. Furthermore, given its low cost (around €50 if manufactured manually; mass-produced it would be much cheaper) and its excellent sensitivity and precision, it is ideal for setting up continuous monitoring networks, even for domestic applications, both in VLEGE installations and in other application domains, such as agriculture and environmental monitoring, where soil moisture measurement is a crucial parameter. This work contributes to the development of more efficient and accessible solutions for harnessing geothermal energy, particularly in installations where dynamic tracking of soil moisture is essential to ensure stable long-term performance.
PB MDPI
YR 2026
FD 2026
LK https://hdl.handle.net/10272/28276
UL https://hdl.handle.net/10272/28276
LA eng
NO Pino Fernández, J. del, Martínez Bohórquez, M. A., Andújar Márquez, J. M., Prieto, M. J. R., & Gómez, J. M. E. (2026). Measurement of Soil Moisture Using Capacitance Measurements: Development of a Low-Cost Device for Environmental and Very-Low-Enthalpy Geothermal Energy Applications. Electronics, 15(7), 1453. https://doi.org/10.3390/electronics15071453
NO This work has been supported by Project PID2023-148456OB-C41, funded by the Spanish Ministry of Science, Innovation, and Universities, as well as by the resources of the Center for Research in Technology, Energy, and Sustainability (CITES) at the University of Huelva.
DS Repositorio Institucional de la Universidad de Huelva
RD 13 jul 2026