Photosynthesis & Solar Photovoltaic Technology
What is photosynthesis and how does photosynthesis work? How is process of photosynthesis linked to photovoltaic technologies? How are they the same and how are they different? This paper will delve into those issues and provide answers to the questions.
Photosynthesis is the process in which green plants create their own food thanks to sunlight shining on them. Animals eat other organisms for their nutrient intake, but plants make their food thanks to the fact that they have chlorophyll. Chlorophyll is the pigment that creates the green color in plants and it “â€¦captures the Sun’s energy and uses it to make sugars out of carbon dioxide from the air and water” (Ohio State University, 2008). The sugars are vital to the process because they provide fuel for the roots of the plant, the stems and leaves of the plant, and allow the plant to continue to grow. And once the plant has made adequate food through sunlight to provide a healthy condition for the plant, it releases oxygen into the air, and of course oxygen is what humans and animals need in order to breathe and live.
In the Handbook of Photovoltaic Science and Engineering, the authors point out that photosynthesis takes place in three phases: a) “light harvesting by antenna systems”; b) “conversion of excitonic energy to chemical energy”; and c) “synthesis and export of products” (i.e., oxygen) (Luque, 2011).
Meanwhile, the conversion of sunlight to electricity is a process known as photovoltaic (PV) technology. Basically it is an artificial strategy to repeat what photosynthesis does in the natural world, Luque explains). In the natural world light is converted into chemical energy, and this is achieved because of: a) “proximal location of molecular components”; b) energy received in “excited states”; and c) “time, concerning the rates of competing processes” (Luque). Moreover, in PV technology Sunlight strikes the solar cells and through artificial “bonding strategies” that are “covalent and non-covalent” electricity is produced.
Author Tetsuo Soga explains that “â€¦the physics of organic PV cells is much closer to that other, much older and more sophisticated, example of organic electronics: photosynthesis” (Mapel, et al., 2007, p. 335). In fact photosynthetic plants and bacteria are known to “â€¦utilize organic molecules similar to those used in organic PV”; in other words, the semiconductor PV structures mimic natural world photosynthesis.
How are photosynthesis and photovoltaic technologies alike and how are they different?
(Alike) Photosynthesis and photovoltaics both take the energy from the Sun and convert it into different energy sources. (Different) And yet they operate in vastly different ways and they produce very different kinds of fuels. (Different). Photosynthesis provides stored chemical potential (sugars) for plant growth; Photovoltaic technologies don’t store energy they provide “instantaneous electrical power” which may be stored but in the instant the Sunlight hits the cell there is a production of electricity (Green, 2011, p. 1). (Alike) The hydrogen that is produced through photovoltaic technologies is “â€¦thermodynamically equivalent to the sugar produced by photosynthesis” (Green, p. 1). (Different) Photovoltaic technologies use “fundamental principles combined with advances in materials” and hence photovoltaic technologies complete solar-to-electrical power and “thereby hydrogen production from water electrolysis”; on the other hand photosynthesis “â€¦originated in an environmentâ€¦and provided for early life forms as a means of self-contained energy production” (Green, p. 1). (Alike) Because the distant future of energy production in society will not be oil or coal, but rather it will be solar, both photosynthesis and photovoltaic technologies will be (and are becoming) pivotal to the survival of humans, animals, and plant species as well.
In conclusion, there are clearly differences and similarities between photosynthesis and the photovoltaic technologies now being built and marketed. The future of electrical energy will be solar, and the future of photosynthesis will be the same as the history of photosynthesis has been. So while one system is being fine-tuned (photovoltaics) the other (photosynthesis) has been around since the early stages of the Earth’s development.
Green, Jenny. (2011). Photosynthesis or photovoltaics: Weighing the impact. ASU News
[Now]. Arizona State University. Retrieved October 29, 2012, from https://asunews.asu.edu/20110512_photosynthesis_photovolatics.
Luque, Antonio, and Hegedus, Steven. (2011). Handbook of Photovoltaic Science and Engineering. Hoboken, NJ: John Wiley & Sons.
Mapel, J.K., and Baldo, M.A. (2007). “The Application of Photosynthetic Materials and Architectures to Solar Cells,” in Nanostructured Materials for Solar Energy
Conversion, T. Soga, Ed, Washington, D.C.: Elsevier.
Ohio State University. (2008). How does photosynthesis work? Wonders of Our World.
Retrieved October 29, 2012, from http://www.governorsresidence.ohio.gov.