Researchers from the University of Arkansas, including J. M. Mangum, L. L. Bonilla, A. Torrente, and P. M. Thibado, have recently published a study on the thermal energy harvesting capabilities of electronic circuits. Their work, appearing in the journal Physical Review E, explores how diodes and capacitors can be used to capture and store energy from temperature differences.
The study is presented in two parts. The first paper, an analytical study, laid the groundwork for the numerical investigations presented in this second paper. The researchers examined two distinct electronic circuits to understand how they can harness thermal energy.
In the first circuit, consisting of a diode and capacitor in series, the researchers found that the capacitor initially charges and then discharges to zero. Importantly, the peak charge on the capacitor increases with temperature, capacitance, and diode quality. This finding suggests that optimizing these parameters could enhance the energy harvesting efficiency of such circuits.
The second circuit is more complex, featuring two current loops with one small capacitor, two storage capacitors, and two diodes wired in opposition. When the diodes are maintained at different temperatures, the researchers observed a steady-state charge accumulation on both storage capacitors. The magnitude of the stored charges was nearly equal, but their signs were opposite. This indicates that the circuit can effectively convert thermal energy into electrical energy, storing it in the capacitors. Notably, when resistors were used in place of diodes, no transient or steady-state charge buildup was observed, highlighting the crucial role of diodes in this energy harvesting process.
The researchers also conducted numerical studies for the time-independent Fokker-Planck equation, which confirmed the steady-state charges observed in the experiments. This theoretical confirmation strengthens the practical applications of their findings.
For the energy sector, these findings could pave the way for more efficient energy harvesting technologies. By leveraging temperature differences, these circuits could potentially capture waste heat from industrial processes or power generation, converting it into usable electrical energy. This could improve overall energy efficiency and reduce waste, contributing to more sustainable energy practices.
This article is based on research available at arXiv.