Solar Panel EfficiencyPresented by Logan Markle, Wesley Patton, and Collin Rhodes

Overview○ History of solar cells○ Current solar cells○ Cell structure and designs○ Organic vs Inorganic cells○ Concentrating Sunlight○ Thermodynamic cycles○ Innovations○ Conclusions

Cool Facts○ 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.

Neat O

!

History of Solar Cells○ 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○ 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 Panelhttp://www.c-changes.com/types-of-solar-panel

Organic vs Inorganic CellsOrganic

○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 LightMirrors: 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/hyperboloid-surface.jpg

Thermodynamic Cycles

○ Steam Rankine systems➢work best for temperatures up to

600°C1

○ 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 o Thinner barriers in

the quantum structure4

o Induction motor5

o Latent thermal energy storage (LTES) integrated concentrated solar power (CSP) plants5

Induction Motor Working Principle Animationhttps://www.youtube.com/watch?v=MnQXnEiIUI8

Conclusions ○ Solar cells now are still inefficient, but

with further research and developments, all of humanity’s energy needs could be met.

○ Current ideas are improving efficiency and accessibility

Sources1. Baker, Erin & Kalowekamo, Joseph. “Estimating the manufacturing cost of purely organic

solar cells.” Sciencedirect.com. 2 February 2009. Web. 30 September 2015.2. Byrnes, Steve. “Why are Solar Panels so Inefficient?” Forbes.com. 4 November 2014. Web.

30 September 2015.3. 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.

4. 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>.

5. 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.

6. Nakano, Yoshiaki. "Ultra-High Efficiency Photovoltaic Cells for Large Scale Solar Power Generation." Ambio 41.S2 (2012): 125-31. Web.

7. 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.

8. 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>.

9. Zhang, Yanmei et. Al. “Comparison of different types of secondary mirrors for solar application.” Sciencedirect.com. February 2014. Web. 30 September 2015.