Over the past decade, the solar industry's growth has been truly remarkable, from dropping nearly 70% in cost since 2014 due to soaring demand to unique variations in design. As a result, the market has seen an ongoing surge that can help catapult the world into a future no longer reliant on fossil fuels.
Some models of these impressive configurations can bend, work in conjunction with other forms of alternative energy, and even mimic dragon scales.
Opportunities and Challenges
Solar energy, at its essence, is a somewhat cut and dry concept. It works by collecting the sun's electromagnetic radiation and converting it into usable electricity or transferring it to a battery where it can be stored for future use. This can be typically done in two main ways, with the more familiar photovoltaic solar (PV) panels or concentrating solar-thermal power (CSP) systems.
The more well-known PV panels have become significantly popular over the past decade, leading to a drop in price and a surge in notoriety. This, coupled with the growing research into CSP and the overall benefits that both options present, has given the entirety of the solar industry a generally positive perception.
These benefits include a renewable and finite source of energy, lower greenhouse emissions, flexibility in design, and, more recently, a decrease in cost and streamlining of technology.
On the contrary, solar energy demonstrates challenges, mainly in terms of location limitations due to varying weather patterns and environmental hazards, though still fewer than their counterpart, and one of the main ones, is only being able to generate sunlight during the day.
That latter point, lack of 24/7 energy generation, has held solar energy back from perhaps reaching its full potential.
That said, engineers from Stanford University have recently announced a device that could mitigate this discrepancy by generating electricity at night.
Thinking Outside of the Box
Engineers Sid Assawaworrarit and his team built a traditional solar PV panel and installed a thermoelectric generator. The thermoelectric generator works by generating energy based on the temperature differences between the solar panels and the surrounding air, which, at night, is significant. This phenomenon is a passive cooling method called radiative cooling.
"During the day
, there's a light coming in from the Sun and hitting the solar cell, but during the night, something of a reverse happens."
"There's actually light going out [from the solar panel], and we use that to generate electricity at night. The photons going out into the night sky actually cool down the solar cell," he says.
Assawaworrarit continues to give an example of this event occurring with grass. "Even if the ambient temperature is a few degrees above freezing, the temperature of the [grass] leaf is actually lower. If the grass is a few degrees below the ambient temperature, and the ambient is slightly above freezing, then the grass might actually be below freezing point."
For now, the device is best used on clearer nights so that the clouds don't reflect the infrared back down on earth. With perfect conditions such as this, the engineer's panels can generate "roughly fifty milliwatts for every square meter of solar panel (50 mW/m2)." Still, they hope to improve those numbers in the future with continued research and refinement.
Others on the Horizon
Even though the Stanford engineer’s technology is remarkable, this concept isn't the first of its kind. A similar device was created by Carvey Ehren Maigue, a student at Mapua University in the Philippines.
Maigue's prototype, the AuReus system, was built in his apartment and can generate enough energy to power a few cell phones. Despite being likewise impressive, his concept is slightly different. It includes a thin outer layer of luminescent particles made from fruit and vegetable waste. This extra layer allows the solar panel to capture ultraviolet rays.
Maigue's product can "be directly used as a stand-alone or can be connected in groups to produce a higher output. It can also be easily integrated into existing solar photovoltaic systems since its electrical output is suitable for such systems as well."
Assawaworrarit and Maigue are just a few of the worthwhile examples of ingenuity, perseverance, and intelligence that, when combined, can create a truly unique and beneficial device. Both of their designs can help advance the world of renewables, proving that there is always room to grow and improve.
Since these two aren't the only ones working to improve solar, we can assume that the future of this sector will continue to yield remarkable designs that can only further society's alternative energy technology.