User:Bhathimani

Himani Bhat. Favorite food: chocolate chip cookies (homemade). Favorite TV show: Skam Norway. Favorite activity: taking walks around Duke while listening to music and thinking.

Making solar energy economically viable:

A grand challenge in engineering identified by the National Academy of Engineering is making solar energy more economical. This typically refers to the efficiency of solar panels. Solar panels currently operate at relatively low efficiency. The average silicon solar panel's efficiency maxes out at around 15%.

This lack of efficiency is typically attributed to both the thermodynamic efficiency limit and the Shockley-Queisser limit. The former states that when energy is converted from one form to another, some energy is always lost. This principle prevents solar energy from being 100% efficient. The second relates to the semiconductors used to construct solar panels. The Shockley-Queisser limit states that only the photons with energies greater than or equal to the band gap energy of the semiconductor can be used to generate energy. All of the photons with energies less than this are wasted. This is a major drain on the efficiency of solar panels.

A potential improvement that would increase the economic viability of solar energy has been posed by a team of researchers from the Massachusetts Institute of Technology[1]. This new method takes solar energy in light form, absorbs it and converts it into heat using carbon nanotubes, and then converts the heat back into light using a bonded layer of silicon and silicon dioxide photonic crystals. This form of light has photons with a narrower range of energies, allowing the light to be better optimized by PV cells.

External Links: Making Solar Panels More Efficient, Nancy S. Giges, The American Society of Mechanical Engineers, created 2 April 2014, accessed 11 September 2019 (Grand Challenge)