Subsurface electrical power system for wireless device charging and storm-induced telluric current harvesting

Background

In remote monitoring and underground sensing, reliable power delivery is a persistent challenge. IoT devices in agriculture, environmental monitoring, and military applications require power where grid connections are impractical. Conventional power solutions rely on physical cabling or periodic battery replacement, but these approaches incur high installation and maintenance costs, vulnerability to environmental damage, and logistical burdens. Similarly, renewable energy sources such as solar or wind are location and weather dependent, leaving critical sensors without energy during adverse conditions. This gap has driven intense interest in alternative methods of supplying continuous power to distributed, hard-to-reach systems.

Current wireless power transfer methods are limited to short ranges, requiring line-of-sight or precise alignment. Inductive coupling demands proximity, while far-field radiofrequency techniques suffer from low efficiency and regulatory power limits. Energy harvesting from ambient mechanical sources requires continuous motion or flux, which is often unavailable in stable underground or weather-protected settings. Attempts to capture transient telluric or lightning-induced currents yield unpredictable, intermittent outputs and face challenges in electrode placement, low conductivity soils, and circuit losses. As a result, existing solutions struggle to provide scalable, reliable, multi-kilowatt power for remote or buried devices without extensive infrastructure.

Technology

This system combines two complementary underground energy harvesting approaches: through-the-soil (TTS) wireless power transfer and weather-driven telluric current capture. In TTS mode, current is injected between surface and deep electrodes to establish a subsurface electric field that buried sensors extract without physical wiring. In storm mode, transient telluric currents induced by distant lightning create a voltage differential between soils at different depths. Electrodes connect to a rectifier circuit that converts and stores direct current in batteries or capacitors. Key parameters—electrode spacing, soil conductivity, circuit impedance—govern capture efficiency, and modular arrays of electrode pairs can scale to multi-kilowatt yields per storm while powering low-power IoT devices continuously.

By exploiting voltage differentials between soil strata rather than mechanical or electromagnetic coupling, this approach eliminates line-of-sight constraints and weather exposure. Underground installation protects the network from environmental hazards and enables simultaneous powering of multiple sensors across radial distances. Unlike conventional renewables dependent on sun or wind, it directly captures electrical energy during weather events and provides steady baseline power, offering unprecedented resilience and simplicity. Scalability is achieved through borefield integration and electrode arrays, allowing predictable performance based on soil and system impedance models, with field tests confirming reliable multi-day operation and multi-kilowatt potential.

Benefits

• Simplified electrical energy harvesting from soil potential differences without moving parts or mechanical conversion
• Continuous low-level wireless power transmission through soil for buried devices, eliminating the need for physical cables
• Opportunistic high-energy capture of telluric currents during lightning storms, enabling periodic multi-kilowatt yields
• Scalable deployment via electrode arrays and integration with ground-source borefields to boost total energy collected
• Non-line-of-sight, underground installation offering inherent weather resilience and protection from environmental damage
• Simultaneous powering of multiple sensors or devices from a single installation, reducing wiring and maintenance costs
• Validated continuous operation and predictable performance through field tests and soil conductivity modeling
• Broad applicability to remote sensing, agricultural monitoring, military installations, and renewable energy infrastructure

Applications

• Remote IoT sensor power delivery
• Agricultural soil sensor network powering
• Underground pipeline integrity monitoring power
• Forward operating base power supply
• Lightning storm energy harvesting

Additional info

A system uses buried electrode pairs to both inject continuous current through soil for wireless power delivery to underground sensors and to capture lightning-induced telluric potential differences. Surface and deep electrodes connect via rectification circuits to storage elements; receivers tap the soil electric field. Harvest efficiency hinges on electrode separation, soil conductivity, circuit impedance, and array size, enabling scalable multi-device powering and storm-driven multi-kilowatt energy harvesting.