Moonlight solar panels can now generate electricity even at night

An innovation with a potential to herald a new era in renewable energy, the Stanford University researchers have developed a new technology allowing solar panels to continue generating electricity at night, under moonlight, and even when it rains or overcast

Hyderabad: An innovation with a potential to herald a new era in renewable energy, the Stanford University researchers have developed a new technology allowing solar panels to continue generating electricity at night, under moonlight, and even when it rains or overcast.

Yes, the Stanford University researchers have addressed the perennial problem of solar panels unable to generate electricity at night.

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They (Stanford researchers) have figured out a way to convert the night skies into power supplies by means of radiative cooling. Popularly called as ‘moonlight panels’, this technology employed developed by Stanford researcher Professor Shanhui Fan, utilises radioactive cooling, a natural process where heat moves away from a surface, especially on a clear night when the Earth radiates infrared energy into space. This temperature difference – between an object and the surrounding air, can then be used to produce electricity.

The unique innovation has the promise to transform sustainable energy, particularly for off-grid applications, although the invention is still at a very early stage, researchers said.

How can solar panels generate electricity at night?

Prof Shanhui and his team attached thermoelectric generators to modified commercial solar panels to collect the dissipating heat, yielding small amounts of usable power. The altered panels yield 50 milliwatts per square meter at night.

“While this is much less than the performance of 200 watts per square meter generated by typical solar panels for a day, it is still sufficient for tiny devices such as LEDs and environmental sensors. Although it is very modest energy generation, there is significant potential for improvement,” the lead researcher Shanhui Fan in the Stanford website, said.

Night solar panels: Bridging the gap for access to energy

“The moonlight panel technology can perfectly fit (integrated) into the existing solar panel technology because the components can be retrofitted into existing solar cells. It would be a perfect and affordable step in improving renewable energy reliability,” the researcher said.

This new technology has the potential to minimise the dependence on batteries, which are expensive and polluting, due to mineral extraction. By powering environmental sensors, IOT devices, and other low-power equipment directly without batteries, it could lead to a reduced ecological footprint from battery manufacture and disposal.

Nighttime solar panels would thus bridge the gap during night hours or the shaded periods when sunshine is otherwise unavailable. Consequently, solar energy adoption could improve significantly in areas with limited sunlight, researchers added.