Fan Lingling, Li Wei, Jin Weiliang, Orenstein Meir, Fan Shanhui
Opt Express. 2020 Aug 17;28(17):25460-25470. doi: 10.1364/OE.397714.
We present a systematic optimization of nighttime thermoelectric power generation system utilizing radiative cooling. We show that an electrical power density >2 W/m, two orders of magnitude higher than the previously reported experimental result, is achievable using existing technologies. This system combines radiative cooling and thermoelectric power generation and operates at night when solar energy harvesting is unavailable. The thermoelectric power generator (TEG) itself covers less than 1 percent of the system footprint area when achieving this optimal power generation, showing economic feasibility. We study the influence of emissivity spectra, thermal convection, thermoelectric figure of merit and the area ratio between the TEG and the radiative cooler on the power generation performance. We optimize the thermal radiation emitter attached to the cold side and propose practical material implementation. The importance of the optimal emitter is elucidated by the gain of 153% in power density compared to regular blackbody emitters.
我们展示了一种利用辐射冷却的夜间热电发电系统的系统优化方法。我们表明，使用现有技术可实现大于2 W/m的电功率密度，比先前报道的实验结果高两个数量级。该系统将辐射冷却与热电发电相结合，在无法获取太阳能的夜间运行。在实现这种最优发电时，热电发电机（TEG）本身所占系统占地面积不到1%，显示出经济可行性。我们研究了发射率光谱、热对流、热电优值以及TEG与辐射冷却器之间的面积比等对发电性能的影响。我们优化了连接到冷端的热辐射发射器，并提出了实际的材料实施方案。与普通黑体发射器相比，功率密度提高了153%，这阐明了最优发射器的重要性。
