Abstract
Thermal energy harvesting from natural resources and waste heat is becoming critical due to ever-increasing environmental concerns. However, so far, available thermal energy harvesting technologies have only been able to generate electricity from large temperature gradients. Here, we report a fundamental breakthrough in low-grade thermal energy harvesting and demonstrate a device based on the thermomagnetic effect that uses ambient conditions as the heat sink and operates from a heat source at temperatures as low as 24 °C. This concept can convert temperature gradients as low as 2 °C into electricity while operating near room temperature. The device is found to exhibit a power density (power per unit volume of active material) of 105 μW cm-3 at a temperature difference of 2 °C, which increases to 465 μW cm-3 at a temperature difference of 10 °C. The power density increases by 2.5 times in the presence of wind with a speed of 2.0 m s-1. This advancement in thermal energy harvesting technology will have a transformative effect on renewable energy generation and in reducing global warming.
Original language | English (US) |
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Pages (from-to) | 1008-1018 |
Number of pages | 11 |
Journal | Energy and Environmental Science |
Volume | 12 |
Issue number | 3 |
DOIs | |
State | Published - Mar 2019 |
Externally published | Yes |
Bibliographical note
Publisher Copyright:© 2019 The Royal Society of Chemistry.