1. Emma ResorSOLAR ENERGY

2. Different kinds of solar
energy
Solar water heating
 Very effective solar
technologies15
 Use heat energy from the sun
to produce hot water15
Solar energy (photovoltaic
energy)
 Popular technology which
converts the sun’s rays into
usable energy through solar
panels11
SOLAR ENERGY BASICS
I
II

3. PHOTOVOLTAIC CELLS: BASICS4
III

4. Account for 90% of PV product sales in 2011
Many forms
Single-crystalline (c-Si) is the most popular
Multicrystalline wafers sawn from ingots
Melt-grown ribbons
Thin hydrogenated amorphous silicon (a-Si:H)
Microcrystalline Si layers grown from gaseous
precursors
 Averages 24% efficiency
Currently researching higher efficiency
crystalline Si
SILICON CELLS16

5.  Ultra-thin layer of phosphorus-doped silicon on top of
a thicker layer of boron-doped silicon.
 P-N junction
 Typical silicon cell produces about 0.5V to 0.6V DC
HOW PV CELLS WORK8
V
IV

6.  Starts with pure semiconductor-grade polysilicon
 Silicon is melted and trace amounts of phosphorous and
boron are added to separate batches of liquid silicon
 It is poured into molds, and an ingot is formed
 Silicon is sliced from blocks
 Subjected to a surface etching process
HOW PV CELLS ARE MADE7
VI

7.  Anti-reflective coating is applied
 Electrical contacts are imprinted on the top
(negative) surface
 An aluminized conductive material is deposited on
the back (positive) surface of each cell
 Each cell is electrically tested and sorted
 Then electrically connected to other cells
HOW PV CELLS ARE MADE7

8. MODULES, PANELS, AND PV ARRAYS3
PV Cells: the
layers of
doped
semiconductor
in a single unit
PV Module:
consists of PV
cell circuits
PV Panel: one
or more PV
modules
PV Array: the
complete
power-
generating
unit

9.  Batteries are sometimes attached to store excess energy
PV SYSTEMS ENERGY STORAGE6
VII

10.  Grid-connected (or utility-interactive)
 Designed to operate in parallel with and interconnected with
electric grid
 PV output can be utilized on-site
 Home can still pull power from the grid
 Stand-Alone
 Designed to operate independent from the electric grid
 Generally designed and sized to supply specific DC/AC
electrical loads
 Simplest S-A is the direct-coupled system
 No electrical storage
 S-A with battery storage
SPECIFIC PV SYSTEMS18

11.  Arrangement of solar panels depends on site
SOLAR PROJECTS12
AngledPanels(inFields)
•Facing south
•Generally has
a 15 to 30
degree angle
SunTrackerPanels
•Follow the
sun’s
progression
•More efficient
Roof-MountedPanels
•Used to
powers
individual
houses
•Angle depends
on roof
XIXVIII

12.  For single-junction cells, energy output is limited by material’s
band gap (threshold frequency/work function)
 Multijunction cells get around this problem
 Higher total conversion efficiency
 Arrangement - different kinds of cells are stacked
 Silicon solar cells become significantly less efficient at higher
temperatures
RESTRICTIONS OF PV CELLS13
What most
solar cells
can absorb
XI

13. 47% converted to heat13
18% of photons pass through the solar cell13
2% is lost from local recombination of newly
created holes and electrons13
Solar Coefficient
Usually it’s negative – meaning that when
temperature rises above 25°C, the solar material
gets less efficient.16
ENERGY LOSS IN PV CELLS

14.  Boosting solar cell conversion efficiencies12
 Lowering the cost of solar cells, modules, and
systems12
 Improving the reliability of PV components and
systems12
 Challenges
 Storing enough energy so that homes do not experience
blackouts12
 Different materials for PV cells are being explored12
 Looking into Thin-Film PV technology17
PHOTOVOLTAIC CELLS: RESEARCH FOCUS

15.  Gallium Arsenide as
opposed to Silicon
 Pros
 Temperature coefficient is
effectively 09
 Has a lower threshold
frequency13
 Panel Production10
 Cons
 Very new and not fully
tested10
 Gallium Arsenide cells are
expected to dominate solar
industry10
ALTERNATIVE CELL
XII

16. Today, electricity production annually
generates:2
40% of U.S. carbon emissions2
$100 billion in health impacts2
$160 billion in related costs from blackouts and
power outages2
Untold additional costs from air, land, and water
pollution2
UNSUSTAINABLE ENERGY

17. US ENERGY SOURCES - 2013
XIII

18. Aesthetic
 People don’t like the look of solar panels
Safety
Generally safe
Location
Convenience
Permit Process – restrictions
Creating jobs
Personal/emotional effects
SOCIAL ASPECT12

19.  Solar is very expensive
 However, costs of
traditional energy are
rising significantly
whereas solar becomes
less expensive as the
technologies improve
 Federal tax credits/breaks
(30%, but can vary by state)
 Panels pay for themselves
 Time varies by location
ECONOMIC EFFECT1

20. ENERGY COST BY STATE20

21. WEST VIRGINIA: CONSUMPTION20

22. WEST VIRGINIA: PRODUCTION20

23. WEST VIRGINIA: PRICE20

24. MARYLAND: CONSUMPTION20

25. MARYLAND: PRODUCTION20

26. HAWAII: CONSUMPTION20

27. HAWAII: PRODUCTION20

28. HAWAII: PRICE20

29.  http://www.eia.gov/state/maps.cfm?v=Energy%20Infrastruct
ure
WORLD ENERGY20

30. PV electricity contributes 96% to 98% less
greenhouse gases than that generated from
coal19
Uses 86% to 89% less water19
Occupies or transforms over 80% less land19
Presents approximately 95% lower toxicity to
humans19
Panels pay for themselves in terms of energy5
ENVIRONMENTAL IMPACTS OF SOLAR
XIV

31.  1 Bennett, Rachel. "Can I Really Save Money by Putting Solar Panels on My
Roof?" NerdWallets MoneySaving Tips. 21 Aug. 2012. Web. 13 May 2014.
 2 "Bringing Clean Competitive Solar Power to Scale." Rocky Mountain
Institute. 12 May 2014.
 3 "Cells, Modules, and Arrays." Florida Solar Energy Center. Florida Solar
Energy Center. 13 May 2014.
 4 "Current PV Technologies." Florida Solar Energy Center. Florida Solar
Energy Center. 13 May 2014.
 5 Fthenakis, Vasilis. How Long Does It Take for Photovoltaics To Produce
the Energy Used? National Society of Professional Engineers, February
2012. PDF
 6 "How A PV System Works." Florida Solar Energy Center. Florida Solar
Energy Center. 13 May 2014.
 7 "How PV Cells are Made." Florida Solar Energy Center. Florida Solar
Energy Center. 13 May 2014.
 8 "How PV Cells Work." Florida Solar Energy Center. Florida Solar Energy
Center. 13 May 2014.
 9 Kapusta, Rich. "Silicon vs. Gallium Arsenide Which Photovoltaic Material
Performs Best." Tech Briefs. NASA, 1 Jan. 2014. 14 May 2014.
CITATIONS: INFORMATION

32.  10 "PV Technology Overview." GroSolar Tech Talk. MD, Columbia. 21 May
2014.
 11 "Solar Energy Basics." Florida Solar Energy Center. Florida Solar
Energy Center. 13 May 2014.
 12 Resor, Jamie P. "Solar Cells." Interview by Emma B. Resor. 25 May
2014. Lecture.
 13 “The Shockley Queisser Efficiency Limit” Solar Efficiency Limits. 17
May 2014.
 14 "Solar." Energy.gov. U.S. Department of Energy. 12 May 2014.
 15 "Solar Hot Water." Florida Solar Energy Center. Florida Solar Energy
Center. 20 May 2014.
 16 "Silicon Materials and Devices R&D." NREL: Photovoltaics Research.
U.S. Department of Energy. 12 May 2014.
 17 "Thin Film PV." Florida Solar Energy Center. Florida Solar Energy
Center. 13 May 2014.
 18 “Types of PV Systems." Florida Solar Energy Center. Florida Solar
Energy Center. 13 May 2014.
 19 “Why It’s Time for Businesses To Wake Up To The Benefits Of Solar
PV.” Think Renewables. 20 May 2014
 20“Maps.” U.S. Energy Information Administration – EIA. 26 May 2014
CITATIONS: INFORMATION

33.  Ihttp://4.bp.blogspot.com/-Mbd-NoSenro/Uh88dqX-
cDI/AAAAAAAAAgU/DDZN1bNPabs/s1600/IMG_5118.JPG
 IIhttp://www.solartubs.com/storeimages/1373477609stainles
s%20steel%20solar%20water%20heater.jpg
 IIIhttp://www-tc.pbs.org/wgbh/nova/solar/images/insi-01.gif
 IV"PV Technology Overview.”
 Vhttp://www.wecusurveillance.com/files/891125/uploaded/s
olarcell2.jpg
 VI"PV Technology Overview.”
 VIIhttp://www.urbansolar.org.uk/images/batteries.jpg
CITATIONS: PICTURES

34.  VIIIhttp://livingonsolarpower.files.wordpress.com/2013/03/sol
ar-panel-mounting-systems.jpg
 IXhttp://www.comerindustries.com/mediaObject/media/prodo
tti/Energia/Pannello-solare/original/Pannello+solare.jpg
 Xhttp://greentechtown.com/wp-
content/uploads/2012/10/Solar-Panels-2.jpg
 XIHgfig
 XIIhttp://jolisfukyu.tokai-sc.jaea.go.jp/fukyu/mirai-
en/2009/img/honbun/4-8.jpg
 XIII"PV Technology Overview.”
 XIVhttp://thumb9.shutterstock.com/display_pic_with_logo/58
80/5880,1261289947,16/stock-photo-background-concept-
illustration-of-sustainable-energy-power-43141264.jpg
 Graphs from slide 21 on: “Maps.” U.S. Energy Information
Administration – EIA. 26 May 2014
CITATIONS: PICTURES