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# Solar Photovoltaics

## Questions from first presentation

1. What are the advantages of thin-film solar cells?
2. What are the differences among the various types of silicon-based cells?
3. How expensive is it to maintain arrays of solar cells?
4. How does the price per installed watt break down? What fraction goes to materials? cell fabrication? module fabrication? installation? inverters?
5. Are any places at market parity without subsidies? How high would a carbon tax have to be for solar PV to be competitive?
6. How do the operational costs of solar PV compare to coal?
7. What are current government programs (domestic and foreign) that subsidize solar PV?
8. Why will it take two decades? Why not focus on smaller, residential uses?
9. Why are modules so expensive?
10. Are there economies of scale for PV arrays that make large installation more efficient or more economical than smaller arrays?
11. How feasible would it be to commercialize the solar cells of highest efficiency? Are there operating concentrated solar PV installations?
12. What is the theoretical efficiency limit for silicon PV? What limits the efficiency of current cells?
13. Silicon is abundant in sand and rocks. Why is it expensive to produce silicon wafers?

### Some further questions

1. How rapidly has the cost per watt of solar photovoltaics declined in recent decades?
2. Are CdTe thin-film cells cheaper to manufacture than silicon cells? Why?
3. What are the prospects for concentrated PV using multijunction cells? Are there conditions where this approach makes more sense?
4. What are dye-sensitized solar cells? The Graetzel cell?
5. Roughly speaking, the cost of solar PV breaks down into three parts: manufacturing the cells, assembling the modules, and installing the panels. There are additional wiring and inverter costs, too. How do these costs compare?
6. How rapidly is the world’s capacity to produce PV growing? China’s? America’s?
7. What is the theoretical limit of PV efficiency? How closely are we likely to approach this limit?

~Peter Saeta 2010 March 10 at 11:29 AM PST

# Preliminary stuff for Solar PVs:

Motivation: Lewis from Caltech noted that in order for solar energy to become economically feasible, substantial improvements to efficiency would have to be made. Such improvements apparently are so great that Muller, within the span of about a paragraph, dismisses, wholesale, the possibility of solar energy supplanting fossil fuels in the next century or so.

Qs:

-- What specific improvements in solar energy will have to be made in order for it to become economically feasible? This question has two components -- both physical and pecuniary limitations must be considered.

-- What improvements have been made recently?

-- What broad physical principles or theories would affect/constrain how solar PV can be made? (Atwood (?) mentioned an "Ergodic limit", for example, that recently one research claimed to have beaten by a factor of 13. What's going on there?)

# Sources for Term Paper (in progress)

1. Materials Availability Expands the Opportunity for Large-Scale Photovoltaics Deployment Cyrus Wadia, A. Paul Alivisatos, Daniel M. Kammen Environmental Science & Technology 2009 43 (6), 2072-2077. 2. Muller, Richard A. Physics for Future Presidents. New York: W.W. Norton and Company, 2008. Print. 3. The Outlook for Crystalline Solar Photovoltaic Technology over the Next Decade

	Dilawar Singh and Philip Jennings, AIP Conf. Proc. 941, 98 (2007), DOI:10.1063/1.2806077


4. United States. USGS. Mineral Commodity Summaries. Print. 5. Kanter, James. "First Solar Claims \$1-a-Watt ‘Industry Milestone’." New York Times [New York] 24 Feb. 2009. Print. 6. S. Taira, Y. Yoshimine, T. Baba, M. Taguchi, H. Kanno, T. Kinoshita, H. Sakata, E. Maruyama, M. Tanaka, Proceedings of the 22nd European Photovoltaic Solar Energy Conference and Exhibition, Milan, Italy, 4, 932 (September 2007). 7. Borenstein, Severin. (2008). The Market Value and Cost of Solar Photovoltaic Electricity Production. UC Berkeley: Center for the Study of Energy Markets. Retrieved from: http://www.escholarship.org/uc/item/3ws6r3j4 8. Break-Even Cost for Residential Photovoltaics in the United States: Key Drivers and Sensitivities

	Paul Denholm, Robert M. Margolis, Sean Ong, and Billy Roberts. National Renewable Energy Laboratory.


9. Ginley, David, Martin A. Green, and Reuben Collins. "Solar Energy Conversion Toward 1 TW."Material Research Society Bulletin 33 (2008). Print. 10. K. Zweibel, J. Mason and V. Fthenakis, Scientific American 298 (1) (2008), p. 64 11. V. Fthenakis, J. Mason and K. Zweibel, Energy Policy 37 (2009), p. 387 12. V.M. Fthenakis, H.C. Kim and E. Alsema, Environmental Sciences and Technology 42 (6) (2008), p. 2168. 13. Smil, Vaclav. Energy in Nature and Society. Cambridge: MIT, 2008. Print. 14. Markoff, John. "Start-Up Sells Solar Panels at Lower-Than-Usual Cost." New York Times [New York] 18 Dec. 2007. Print. 15. Ramchandra Bhandari, Ingo Stadler, Grid parity analysis of solar photovoltaic systems in Germany using experience curves, Solar Energy, Volume 83, Issue 9, September 2009, Pages 1634-1644, ISSN 0038-092X, DOI: 10.1016/j.solener.2009.06.001. (http://www.sciencedirect.com/science/article/B6V50-4WKY7BJ-2/2/401a6845036eca74849f064ea5d64f75) Keywords: Solar photovoltaic; Benefit cost analysis; Breakeven analysis; Grid parity

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