Opportunities for Radiative Cooling
Jeremy Rodriguez
City College
Abstract
On September 12, 2019 an article published in the New York Times described an invention by Dr. Raman from the University of California Los Angeles that was able to power a lightbulb via a phenomenon called radiative cooling. This technology holds many drawbacks in maximum energy production which was 3 orders of magnitude less than a normal solar cell and theoretically is capped at 50 times less energy per square meter. The device does have a lot of promise being a useful addon in many solar cells to produce energy when the sun is down as well as recycling energy expended by other devices such as computers. Since technology can aid in many different places it could become commercially viable and is likely able to lessen the effects of CO2 emissions by saving energy.
The New York Times article published an article on September 12, 2019 called, ‘New Device Harvests Energy in Darkness’ by Rebecca Boyle which discusses a new invention that was able to generate power for a lightbulb in the dark. Scientist and Entrepreneur Aaswath Raman’s invention was powered through a phenomenon called radiative cooling. His company, SkyCooling has already used this effect prior to this for other innovations. The phenomenon itself is simple, through certain materials the heat builds up on one side allowing the other to be cooler. In this transition from hot to cold, which happens as the sun goes down, we can harness some of the thermal energy to power objects without dwindling solar batteries or CO2.
The invention succeeded in powering a light bulb turning on however it has many limitations. The article stated that the energy created was, “about three orders of magnitude lower than what a typical solar panel produces” showing the technology is not able at this current place to replace or compete with solar. The effect also seems to be limited, “ Researchers … calculated that at best only about 4 watts of energy can be extracted from a square meter of cold space. By contrast… the most common type of solar panel generates about 200 watts per square meter in direct sunlight.” From this, it is clear that this new energy may not be the opening to a completely new world. As a power source, it most likely will not reach anything as viable as solar panels. However, Dr. Raman clarifies that “thermoelectric devices could complement solar-powered lights in areas where changing batteries is a challenge, like on street lamps or in remote areas far from electrical grids”. Utilizing this technology to generate energy in specific places can aggregate to a large amount of power generated and support a major downside to solar. These minor roles are a niche for the technology because it could be integrated into space for solar panels rather than compete against them.
This invention and use of our understanding can easily lead to more innovation and new technology. As said, “after the sun sets, solar cells don’t work and winds often die down, even as demand for lighting peaks” Assuming that there is always some fluctuation in heat then there is an opportunity to generate energy. Things like friction, physical contact, and even sound waves generate some amount of heat. Over time there could be ways to gather much more energy from any of these minor sources of energy. One potential use of the technology could be a further deploying them to building walls, computers, and likely other places to recapture heat we emit. Since it’s powered by only heat it is so versatile, it can be used anywhere. This technology brings an opportunity to recycle energy rather than just generate it.
A drawback of the technology is cost. As mentioned in the article, “…thermoelectric devices are less efficient and more expensive than photovoltaic cells..”, this is damaging since it isn’t as versatile if the cost is a major impediment. This issue also seems to be greater since “One challenge will be improving the device’s efficiency without raising its costs”. Even though the power is versatile it is not likely to be used in places that need it most, where costs to build regular solar panels are steep.
The technology promises to be commercially viable and ecologically liberating however major discoveries need to be made for this to happen. Since it could be used virtually anywhere and aid a major drawback of solar panels it can be easily sold as an addon once costs subside. Though not a paradigm shift it offers to expand the use of scientific knowledge via its implementation. There are likely other ways that technology will aid society from lighting rural areas to saving bills for city dwellers. Where else can we implement natural phenomena to generate energy?
References
Boyle, R. (2019, September 12). Transformative? New Device Harvests Energy from Darkness. Retrieved from https://www.nytimes.com/2019/09/12/science/solar-energy-power-electricity.html
