As solar cells have become an increasingly popular source of clean energy, it’s common to see them all over the roofs of homes in sunny locals across America. While solar energy certainly has its benefits and solar technology has come a long way, there may be an even bigger change on the horizon.

Most are panels not yet capable at operating at peak efficiency due to technical limits. You have the option to purchase high-efficiency solar panels that operate at a higher efficiency close to the maximum threshold but there is still room for improvement according to the theoretical limit Shockley and Queisser calculated in 1961 for solar energy cells. The Shockley-Queisser limit predicts a max energy efficiency of only 32%. However, new technology, nicknamed “hot solar cells” may shatter decades of theoretically established limits.  

Named one of MIT’s 10 Breakthrough Technologies of 2017, David Dierman, Andrej Lenert, Ivan Celanovic, Evelyn N. Wang, Walkt Chan, and Marin Soljacic are advancing solar cell technology, or the field of thermophotovoltaics, in an incredible way. Thermophotovoltaics or (TPV) is “a method of converting heat to electricity using infrared light as an intermediary.” In other words, it’s the process of converting heat into light, then converting that light into power.

Hot solar cells are being created as a means of improving the efficiency of traditional solar panels. These cells are designed to be used as a top layer for solar panels and can direct certain frequencies of light to the solar panels to make them more efficient.

Current solar panels are made of silicon and only absorb light between violet and red on the color spectrum. Hot solar cells help solve this problem by filtering out and recycling unusable wavelengths of light. They consist of an absorber, emitter, and filter. The absorber uses carbon nanotubes to absorb up to 99.96% of all light and turn it into heat. Once the absorber reaches 1,800 degrees Fahrenheit (roughly the same temperature as lava), the heat is converted back into the light and filtered through a photonic crystal, that has been engineered at a nanoscale to filter light wavelengths.

The filtered light is then emitted by the optical filter, which transmits accepted wavelengths and reflects the rest back into the hot solar cell, in a system referred to as “photon recycling.” This doubles the efficiency of the system because the “recycled light” continues to generate heat and power for the hot solar cell.

Hot solar cells are designed to reduce the number of solar panels necessary to power a home or building by about half. These high-tech covers are so efficient they could potentially double the efficiency of current solar panels, shattering the theoretical Shockley-Queisser Limit. This alone would reduce the needed square footage to generate sufficient energy for a home for example.

If you have solar panels, and perhaps even if you don’t, you’re probably wondering where you can get your hands on some hot solar cells. Unfortunately, they have not entered mass production. The technology is about 10-15 years from entering the market. MIT’s current device is still in the developing stages and only works at 6.8% efficiency, in a vacuum. The MIT team is working to find a way to develop larger panels that could be made more affordable, as the current design is very small and expensive to build.

The good news is that solar is becoming so popular it is predicted to become the cheapest method of creating electricity within the next 15 years—just in time for hot solar cells to hit the market. The other good news is that, despite only having a small prototype, the hot solar cells that have been tested all perform exactly as theoretically anticipated.

Hot solar cells will also make energy storage more efficient as well. It is easier to store energy as heat, rather than as electricity, as less energy is lost. This would potentially allow solar energy to consistently run at full capacity, even in overcast conditions.

Although hot solar cells may not be on the market for the next 10 years, there are sustainable ways to source the energy for your home. Kiwi Energy is proud to offer environmentally conscious energy options for our customers. Kiwi Energy offers different plans so you can pick one that suits your needs. Find a plan that works for you and sign up for Kiwi Energy today.