New Knowledge of Science and Technology: Deep Space Low Temperature Power Generation
One obvious shortcoming of solar power is that it is completely powerless at night. For the first time, an international research group has used temperature differences between deep space and the Earth to generate electricity. Researchers believe this approach could be a useful complement to solar power technology at night.
Shanhui Fan, one of the authors of the study, said, "The vast space is a kind of thermal power resource. In photoelectric physics, there is a wonderful symmetry between the two methods of harvesting energy from incoming and outgoing radiation.
This means that, contrary to solar power, the process of heat leaving can also generate electricity. This study is the first experiment to prove that the theory is feasible, but the efficiency is still too low.
"The electricity we can generate in this experiment is far below the theoretical upper limit." Masashi Ono, another author of the study, said. Their equipment generates about 64 nanowatts of electricity per square metre at night against the infinite depth of the sky.
Researchers believe that in theory the device should generate 4 watts of electricity per square metre, enough to power night-running equipment. By contrast, solar panels now generate 100 to 200 watts of electricity per square metre. The study was recently published in the Applied Physics Letters.