Solar Panel
Efficiency
Presented by Logan Markle,
Wesley Patton, and Collin
Rhodes
Overview
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History of solar cells
Current solar cells
Cell structure and designs
Organic vs Inorganic cells
Concentrating Sunlight
Thermodynamic cycles
Innovations
Conclusions
Cool Facts
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We are able to utilize 85% of the sun’s energy
in theory (but as of now our technology only
allows us to harness about 25%)
The 15% we can’t utilize is dissipated in the
atmosphere.
History of Solar Cells
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1839 – Alexandre Edmond Becquerel observed the
photovoltaic effect through an electrode in a
conductive solution which was exposed to light
1883 – Charles Fritts developed a solar cell using
selenium and a thin layer of gold foil to form a device
that had less than 1% efficiency
1954 – April 25, Bell Labs announced the first practical
silicon solar cell which had 6% efficicency
1985 – 20% efficienct solar cells were created by the
Centre for Photovoltaic Engineering at the University
of New South Wales
Current Solar Cells
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2012 – 3D PV cells with 30% + energy
efficiency (still relatively inefficient)
Takes many panels to produce the power
needed for large populations
Fragile and don’t have long shelf lives
Cell Structure and Design
○Large grain solar
cells8
○Periodic silver
nanowires4
Types of Solar Panel
http://www.c-changes.com/types-of-solar-panel
Organic vs Inorganic Cells
Organic
○ Cheaper to produce
○ Produce less energy than Inorganic cells
○ Degrade quicker than Inorganic cells
○ Cost to produce still too high to be viable
Inorganic
○ More expensive to produce than Organic cells
○ Produces more energy than Organic cells
○ Takes longer to degrade than Organic cells
Concentrating Light
Mirrors: Why are they important?
○ Concentrate sunlight on the
solar cell
○ Allow more power to be
produced
What shape of mirror is best?
○ Answer: Hyperboloidal
http://www.georgehart.com/skewers/hyperboloidsurface.jpg
Thermodynamic Cycles
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Steam Rankine systems
➢ work best for temperatures up to 600°C1
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CO2 recompression Brayton cycles
➢ work better than the Rankine system
between 600°C and 1000°C1
Picture of Steam Rankine System
http://www.azwater.gov/azdwr/waterManagement/documents/TheWaterDemandofPowerGeneration.pdf
CO2 Recompression
Brayton Cycles
http://www.netl.doe.gov/research/coal/energy-systems/turbines/supercritical-co2-power-cycles
Innovations
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Thinner barriers in
the quantum
structure4
Induction motor5
Latent thermal
energy storage
(LTES) integrated
concentrated solar
power (CSP) plants5
Induction Motor Working Principle Animation
https://www.youtube.com/watch?v=MnQXnEiIUI8
Conclusions
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Solar cells now are still inefficient, but with
further research and developments, all of
humanity’s energy needs could be met.
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Current ideas are improving efficiency and
accessibility
Sources
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Baker, Erin & Kalowekamo, Joseph. “Estimating the manufacturing cost of purely organic solar cells.”
Sciencedirect.com. 2 February 2009. Web. 30 September 2015.
Byrnes, Steve. “Why are Solar Panels so Inefficient?” Forbes.com. 4 November 2014. Web. 30
September 2015.
Dunham, Marc T., and Brian D. Iverson. "High-efficiency Thermodynamic Power Cycles for
Concentrated Solar Power Systems." Renewable and Sustainable Energy Reviews 30 (2014): 758-70.
Web.
Hajimirza, Shima, Georges El Hitti, Alex Heltzel, and John Howell. "Specification of Micro-Nanoscale
Radiative Patterns Using Inverse Analysis for Increasing Solar Panel Efficiency." J. Heat Transfer
Journal of Heat Transfer 134.10 (2012): 102702. Specification of Micro-Nanoscale Radiative Patterns
Using Inverse Analysis for Increasing Solar Panel Efficiency. American Society of Mechanical
Engineers. Web. 24 Sept. 2015.
<http://heattransfer.asmedigitalcollection.asme.org/article.aspx?articleid=1484411>.
Mokhtari, B., A. Ameur, L. Mokrani, B. Azoui, and M. F. Benkhoris. "DTC Applied to Optimize Solar Panel
Efficiency." IEEE Xplore. Industrial Electronics, 2009. IECON '09. 35th Annual Conference of IEEE, 3 Nov.
2009. Web. 23 Sept. 2015.
Nakano, Yoshiaki. "Ultra-High Efficiency Photovoltaic Cells for Large Scale Solar Power Generation."
Ambio 41.S2 (2012): 125-31. Web.
Nithyanandam, K., and R. Pitchumani. "Cost and Performance Analysis of Concentrating Solar Power
Systems with Integrated Latent Thermal Energy Storage." Energy 64 (2014): 793-810. Web.
Todorov, Teodor K., Jiang Tang, Santanu Bag, Oki Gunawan, Tayfun Gokmen, Yu Zhu, and David B.
Mitzi. "Beyond 11% Efficiency: Characteristics of State-of-the-Art Cu 2 ZnSn(S,Se) 4 Solar Cells."
Advanced Energy Materials Adv. Energy Mater. 3.1 (2012): 34-38. Beyond 11% Effi Ciency:
Characteristics of State-of-the-Art Cu 2 ZnSn(S,Se) 4 Solar Cells. Advanced Energy Materials. Web. 24
Sept. 2015. <http://onlinelibrary.wiley.com/doi/10.1002/aenm.201200348/pdf>.
Zhang, Yanmei et. Al. “Comparison of different types of secondary mirrors for solar application.”
Sciencedirect.com. February 2014. Web. 30 September 2015.