Photosynthesis: Plant Cells vs. Solar Cells

Photosynthesis: Plant cells vs.

Solar Cells Chevon Allen 01/23/2010 SCI-115 Professor Garcia Photosynthesis and the semiconductor-based solar cell are very similar process with different ways of reaching the same goal. In photosynthesis, plant cells harness the solar energy of the sun with carbon dioxide to transform water molecules into hydrogen, oxygen, and electrons. Just like photosynthesis, Semi conductor based solar cells harness the solar energy of the sun for the same purposes. Solar cells use a semiconductor material like Silicon (Si) to harvest the energy through; much like a plant uses its Chlorophyll to harness its energy. 2. ) Another similarity that can be shared between the two systems would be the way the energy is produced.

The light reactions of photosynthesis can be compared to the production of electricity by solar cells. This process is called photovoltaics. The electrons in the solar cell capture light energy and are boosted to a high energy level where they are accepted by the wire making up the electrical circuit. The electrons then do work, such as to run an electric motor. Then the electrons lost by the solar cell must be replenished. This is done by completing the electrical circuit.

In photosynthesis the electrons lost by the pigments involved are replaced by splitting water. (1. ) Although they have similar purposes for harvesting energy they are very different as well. Plants are less efficient at capturing the energy in sunlight than solar cells mostly because they have too much evolutionary baggage. Plants have to power a living thing, whereas solar cells only have to send electricity down a wire. This is a big difference because if photosynthesis makes a mistake, it makes toxic byproducts that kill the organism.

Photosynthesis has to be conservative to avoid killing the organisms it powers. Scientific Daily 2011). Another difference is during photosynthesis plant cells derive their energy directly from the sun while solar cells use panels. Majority of plants use the full intensity of sunlight but divert some of it to protect itself from damage. However, photovoltaics (solar cells) use the secondary material to gain that photo- conversion edge over plants.

Photosynthesis and Thermodynamics are very closely related. Thermodynamics is the branch of science dealing with the laws and theories related to energy in the universe. The first law of thermodynamics states energy can be neither created nor destroyed.In photosynthesis carbon dioxide and water give up electrons to form glucose and oxygen. In relation to solar cells it converts that solar energy into electricity to power a light bulb. The second law of Thermodynamics states that “in all energy exchanges, if no energy enters or leaves the system, the potential energy of the state will always be less than that of the initial state.

” This is true in photosynthesis because when carbon dioxide and water go through the process of becoming glucose and oxygen they lose electrons and the energy they began with is decreased because of the electron transfer. Laws of Thermodynamics, 2010) Throughout this paper we have discussed photosynthesis and the two very similar yet different ways of achieving it. With photosynthesis being one of the main sources of how plant, most bacterial, and small animals and organisms thrive it is comforting to know that we have a backup system to this wonderful process. Solar cells may not be as complex and may utilize more initial energy but Plant cells have the best way of processing photosynthesis. Sources used: 1.

Photovoltaics and Photosynthesis.Retrieved January 23,2012 from http://staff. jccc. net/pdecell/photosyn/solar. html 2. DOE/National Renewable Energy Laboratory (2011, May 12).

Improving photosynthesis? Solar cells beat plants at harvesting sun’s energy, for now. ScienceDaily. Retrieved January 22, 2012, from http://www. sciencedaily. com /releases/2011/05/110512151408.

htm 3. Farabee, M. (2010). LAWS OF THERMODYNAMICS. Retrieved January 23,2012 from http://www.

emc. maricopa. edu/faculty/farabee/biobk/biobookener1. html