Over the last decade, solar panels have taken the world by storm, and their popularity does not appear to be waning anytime soon. In fact, the number of solar systems is expected to exceed 3 million by 2021. Although solar systems are not new, many people are unfamiliar with their technology. You can learn more about how solar panels function here, but one huge question remains: do solar panels work in gloomy weather? What about after dark? Can solar panels be used at night?
Researchers created a device that can generate electricity from heat radiation using technology comparable to night-vision goggles. Following a substantial advancement in thermal capture technology, the sun’s immense energy may soon be harnessed in the dead of night. Solar radiation heats the earth’s crust significantly during daylight hours, but that energy is lost into the coldness of space when the sun goes down.
Researchers at UNSW Sydney’s School of Photovoltaic and Renewable Energy Engineering have successfully tested a system that converts infrared heat into electrical power.
The researchers, who included members of the ARC Centre of Excellence in Exciton Science, employed a power-generation gadget known as a ‘thermo-radiative diode,’ which is similar to the technology seen in night-vision goggles.
We normally think of light emission as using power, but in the mid-infrared, where we are all shining with radiant energy, we have proved that it is feasible to extract electrical power.
Nicholas Ekins-Daukes
“In the late 18th and early 19th centuries, it was recognized that the efficiency of steam engines depended on the temperature difference across the engine, and the subject of thermodynamics was born,” said Exciton Science Associate Investigator Nicholas Ekins-Daukes, the team’s leader.
“The same concepts apply to solar power: the sun serves as the hot source, and a relatively cool solar panel on Earth’s surface serves as the cold absorber. This enables the generation of power. However, when we consider the infrared emission from the Earth into outer space, the Earth is suddenly the relatively warm body, while the wide expanse of space is exceedingly cold. It is also conceivable to create electricity from this temperature differential using the same thermodynamic principles: the emission of infrared light into space.”
Do Solar Panels Produce Energy At Night?
No, technically. Solar panels do not generate electricity at night. To generate power, photovoltaic cells in solar panels require sunlight. But that’s not the main point. Solar panels provide two indirect alternatives for evening energy.
Solar panels work tirelessly all day to generate electricity from the sun. At night, they also support sustainable solar energy options. Through net metering and solar battery storage, you can continue to benefit from their energy production after sunset. So, how do solar panels function at night? These are the two possible indirect routes.
Solar energy is transforming the way we power our lives. Electric grid connection with net metering and solar battery storage both allow your solar energy system to produce electricity when your solar panels are not in use, allowing you to rock around the clock.
Norwegian researcher Rune Strandberg pioneered the theoretical feasibility of such a device, while Stanford University researchers are studying various techniques to capture thermal energy at night. The amount of energy produced by this new test is tiny (approximately equivalent to 0.001% of a solar cell), but the proof of concept is substantial.
“We normally think of light emission as using power, but in the mid-infrared, where we are all shining with radiant energy, we have proved that it is feasible to extract electrical power,” Nicholas explained.
“We don’t yet have the miraculous material that will make the thermoradiative diode a commonplace reality, but we did a proof of principle and are excited to see how much we can improve on this result in the next years.”
The team is now looking forward to the next phase of research, which will involve developing and refining their own devices to harness the power of the night, as well as welcoming possible industrial partners.
