Researchers Build Low-Cost System To Revolutionize Energy Production At Night

Researchers at Stanford University have come up with a novel method to generate electricity at night time. The new energy generation process is an off the grid solution that uses existing technology, a combination of thermoelectric power generation system and radiative cooling.

The system aims to make up for the time when solar energy harvesting is not possible, i.e. at night or when the sunlight is limited. It also promises to be an affordable alternative to it, as harnessing solar energy in itself is quite an expensive method.

The research, now published in The Optical Society (OSA) journal Optics Express, focuses on harnessing energy from temperature difference as an alternative. This is called thermoelectric power generation. The devices that can convert temperature difference between two junctions into electrical energy are called thermoelectric power generators.

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With this principle, it is also possible to ¡°convert waste heat from automobiles into usable power," says Lingling Fan, first author of the paper.

How it works

The research demonstrates an enhanced thermoelectric power generation system that can generate 2.2 Watts per square meter through a rooftop device built using existing technologies.

In the study, the researchers optimised each step of thermoelectric power generation to maximize nighttime power generation. For this, they increased the amount of heat flowing into the system so that more energy could be harnessed through the temperature difference. More of this available energy was then harnessed by using new commercially available thermoelectric materials

(Representative Image: Reuters)

The research promises a ¡°practical material implementation¡± during the entire process. For instance, the team used an optimal emitter in place of a regular blackbody emitter and the claimed 153 percent gain in power density justifies the decision.

The research also calculates the optimal area of the thermoelectric power generator for maximum efficiency. It notes that a device covering one square meter of a rooftop could be the best bet for the purpose.

For now, the researchers are also examining the possibilities of using the system during the day. If and when such a design comes up, the practicality of the low-cost and sustainable energy generation system will increase multi-fold.