Solar Energy Physics 52. Outline Basics of today’s power generation The Sun Photovoltaic Cell...

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Solar Energy Physics 52

Transcript of Solar Energy Physics 52. Outline Basics of today’s power generation The Sun Photovoltaic Cell...

Page 1: Solar Energy Physics 52. Outline Basics of today’s power generation The Sun Photovoltaic Cell Modules and systems A little economics Conclusion Quiz.

Solar Energy

Physics 52

Page 2: Solar Energy Physics 52. Outline Basics of today’s power generation The Sun Photovoltaic Cell Modules and systems A little economics Conclusion Quiz.

Outline

• Basics of today’s power generation• The Sun• Photovoltaic Cell• Modules and systems• A little economics• Conclusion• Quiz

Page 3: Solar Energy Physics 52. Outline Basics of today’s power generation The Sun Photovoltaic Cell Modules and systems A little economics Conclusion Quiz.

Power Generation

Current energy usage by mankind

7 x 1012 W

Page 4: Solar Energy Physics 52. Outline Basics of today’s power generation The Sun Photovoltaic Cell Modules and systems A little economics Conclusion Quiz.

Renewable and Non-Renewable energy Sources

• Non-Renewable– Oil– Natural Gas– Coal– Nuclear

• Renewable– Hydro-electric– Wind– Bio Fuels– Solar

• Direct heating• Photo-Voltaic

Page 5: Solar Energy Physics 52. Outline Basics of today’s power generation The Sun Photovoltaic Cell Modules and systems A little economics Conclusion Quiz.

Current World Energy Sources

39%

23%

23%

7%7% 1%

Oil

Gas

Coal

Nuclear

Hydro

Other

Other includes wind and solar power

Page 6: Solar Energy Physics 52. Outline Basics of today’s power generation The Sun Photovoltaic Cell Modules and systems A little economics Conclusion Quiz.

The Sun

Page 7: Solar Energy Physics 52. Outline Basics of today’s power generation The Sun Photovoltaic Cell Modules and systems A little economics Conclusion Quiz.

Solar Power

The total power from the sun is about 4 x 1026W

a) How much total power hits the earth?

b) What is the power density (W/m2)at the top of the earth’s atmosphere?

References on Solar energy: 1) Review paper by L. Kazmerski, of National Renewable Energy Laboratory, Golden, CO 2) Fundimentals of Renewable Energy ProcessesBy Also DaRosa (Stanford)

Page 8: Solar Energy Physics 52. Outline Basics of today’s power generation The Sun Photovoltaic Cell Modules and systems A little economics Conclusion Quiz.

Solar Power

a) How much total power hits the earth?

Powere = PSRe2/4D2

Pe= 1.7 x 1017W

Total human energy usage = 7 x 1012W

Page 9: Solar Energy Physics 52. Outline Basics of today’s power generation The Sun Photovoltaic Cell Modules and systems A little economics Conclusion Quiz.

Solar Power

b) What is the solar power density (W/m2)at the top of the earth’s atmosphere?

Power Densitye = PS/4D2

Power Densitye = 1360 W/m2

(Solar Constant)

Page 10: Solar Energy Physics 52. Outline Basics of today’s power generation The Sun Photovoltaic Cell Modules and systems A little economics Conclusion Quiz.

Solar Power

c) What is the solar power density at the surface of the earth?

Step 1: Average over all latitudes, day and night is ¼ solar constant

Step 2: Average attenuation due to clouds and other absorption is about 50%

Average Insolation = 1360W/m2 x ¼ x ½

= 174W/m2

Page 11: Solar Energy Physics 52. Outline Basics of today’s power generation The Sun Photovoltaic Cell Modules and systems A little economics Conclusion Quiz.

Average Insolation

Page 12: Solar Energy Physics 52. Outline Basics of today’s power generation The Sun Photovoltaic Cell Modules and systems A little economics Conclusion Quiz.

Photovoltaic Cells

Page 13: Solar Energy Physics 52. Outline Basics of today’s power generation The Sun Photovoltaic Cell Modules and systems A little economics Conclusion Quiz.

Photovoltaic Cell

Page 14: Solar Energy Physics 52. Outline Basics of today’s power generation The Sun Photovoltaic Cell Modules and systems A little economics Conclusion Quiz.

Photovoltaic Cell

• Semiconductor material that absorbs photons with energy greater than the material bandgap

• pn junction with bias allows current to be generated from the electron hole pair that is generated by the absorbed material

• > 95% of todays cells are simple silicon

Page 15: Solar Energy Physics 52. Outline Basics of today’s power generation The Sun Photovoltaic Cell Modules and systems A little economics Conclusion Quiz.

The silicon solar cell, invented in 1955, quickly became the standard for space power.

Solar Cells

Page 16: Solar Energy Physics 52. Outline Basics of today’s power generation The Sun Photovoltaic Cell Modules and systems A little economics Conclusion Quiz.

Solar Power

d) What size (m2) photovoltaic cell would you need to power your house or apartment?

Need to assume something for Photovoltaic efficiency

Page 17: Solar Energy Physics 52. Outline Basics of today’s power generation The Sun Photovoltaic Cell Modules and systems A little economics Conclusion Quiz.

Efficiency of PV Cells

Page 18: Solar Energy Physics 52. Outline Basics of today’s power generation The Sun Photovoltaic Cell Modules and systems A little economics Conclusion Quiz.

Historical Silicon PV Efficiency

Manufacturers Concentrated on Cost Reduction During this Period

Page 19: Solar Energy Physics 52. Outline Basics of today’s power generation The Sun Photovoltaic Cell Modules and systems A little economics Conclusion Quiz.

Photovoltaic Cells

Multi-junction cells now have demonstrated efficiencies approaching 40% and are for sale at rated efficiency of >25%

Multi-junction cells lead to high cost semiconductor devices. Concentrator systems allow dramatic reduction in the amount of active material

Page 20: Solar Energy Physics 52. Outline Basics of today’s power generation The Sun Photovoltaic Cell Modules and systems A little economics Conclusion Quiz.

Concentrating Solar Power

Example of a concentrator system for solar cells comes from SolFocusAllows for a 500x reduction in the amount of PV area needed

Page 21: Solar Energy Physics 52. Outline Basics of today’s power generation The Sun Photovoltaic Cell Modules and systems A little economics Conclusion Quiz.

Solar Power

d) What size (m2) photovoltaic cell would you need to power your house or apartment?

Power Generation = Insolation x PV efficiency

= 200W/m2 x 0.25

=50W/m2

Energy/Day= 50W/m2 x 24 hr =1.2KW-hr/m2

My house uses 1000KW-hr/mo. or 33KW-hr/day

Area = 33KW-hr/day/1.2KW-hr/day m2

Area = 28m2

Page 22: Solar Energy Physics 52. Outline Basics of today’s power generation The Sun Photovoltaic Cell Modules and systems A little economics Conclusion Quiz.

Solar Power

One More Idea

Off Grid: Your power system must store energy for use at night and cloudy days. Leads to expensive battery systems. It must also be robust enough to meet peak demand (Examples: Boats, Satellites, very remote sites)

On Grid: Your power system shares its power with the public or private utility, selling power when generation exceeds demand and buying power when generation is less than demand.

Page 23: Solar Energy Physics 52. Outline Basics of today’s power generation The Sun Photovoltaic Cell Modules and systems A little economics Conclusion Quiz.

Distributed Generation Strategies are Shaping the FutureDistributed Power Generation will be the Future Architecture

1900’s 2000’s

Page 24: Solar Energy Physics 52. Outline Basics of today’s power generation The Sun Photovoltaic Cell Modules and systems A little economics Conclusion Quiz.

Economics and projections

Page 25: Solar Energy Physics 52. Outline Basics of today’s power generation The Sun Photovoltaic Cell Modules and systems A little economics Conclusion Quiz.

Silicon Roadmap Cost

1

10

100

1 10 100 1,000 10,000 100,000

Cumulative Production (MW)

Module Price ($/W) ($2002)

Historical

Projected

1980$21.83/W

1990$6.07/W

2000$3.89/W

2010$1.82/W

2013$1.44/W2002 Roadmap

Solar Panel Price Drops by 19% With Each Doubling in Manufacturing Capacity

PV Experience Curve

Rough Rules of Thumb

• Prices halve every decade• Market size increases

ten-fold every decade Silicon Shortage

2006$3.50/W

Page 26: Solar Energy Physics 52. Outline Basics of today’s power generation The Sun Photovoltaic Cell Modules and systems A little economics Conclusion Quiz.

Silicon Roadmap Cost1

10

100

1 10 100 1,000 10,000 100,000

Cumulative Production (MW)

Module Price ($/W) ($2002)

Historical

Projected

1980$21.83/W

1990$6.07/W

2000$3.89/W

2010$1.82/W

2013$1.44/W2002 Roadmap

Incremental Improvements in Silicon Technology will Continue to Drive Solar Panel Price Reduction

Continuous Cost Reduction

Retail Parity

Page 27: Solar Energy Physics 52. Outline Basics of today’s power generation The Sun Photovoltaic Cell Modules and systems A little economics Conclusion Quiz.

Photovoltaic Production

Page 28: Solar Energy Physics 52. Outline Basics of today’s power generation The Sun Photovoltaic Cell Modules and systems A little economics Conclusion Quiz.

Market Growth

0

500

1,000

1,500

2,000

2,500

1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008

Industry Shipments (MW)

On-Grid Utility

On-Grid Commercial

On-Grid Residential

Indoor

Consumer Power

Remote Habitation

Remote Industrial

Source: Strategies Unlimited

Page 29: Solar Energy Physics 52. Outline Basics of today’s power generation The Sun Photovoltaic Cell Modules and systems A little economics Conclusion Quiz.

Walldürn, Germany – 8.0 kW

Page 30: Solar Energy Physics 52. Outline Basics of today’s power generation The Sun Photovoltaic Cell Modules and systems A little economics Conclusion Quiz.

Osaka, Japan – 5 kW

Page 31: Solar Energy Physics 52. Outline Basics of today’s power generation The Sun Photovoltaic Cell Modules and systems A little economics Conclusion Quiz.

Microsoft Silicon Valley Campus

Page 32: Solar Energy Physics 52. Outline Basics of today’s power generation The Sun Photovoltaic Cell Modules and systems A little economics Conclusion Quiz.

18801860

500

0

1000

1500

1900 1920 1940 1960 1980 2000 2020 2040 2060

Surprise

Geothermal

Solar

Biomass

Wind

Nuclear

Hydro

Gas

Oil &NGL

Coal

Trad. Bio.

Exa

jou

les

Source: Shell, The Evolution of the World’s Energy Systems, 1995

Renewable Energy Drivers:•Climate Change•Fossil Fuel Depletion

Sources of Energy 50 years from now

Page 33: Solar Energy Physics 52. Outline Basics of today’s power generation The Sun Photovoltaic Cell Modules and systems A little economics Conclusion Quiz.

Conclusions

Page 34: Solar Energy Physics 52. Outline Basics of today’s power generation The Sun Photovoltaic Cell Modules and systems A little economics Conclusion Quiz.

Solar power future

• Environmental– With the pressure to reduce greenhouse gasses

people and governments will invest in solar energy to reduce costs and expand deployment

• Political– Strong desire in US to reduce dependence on foreign

sources of energy (oil)

• Economic– Cost of oil and natural gas will continue to increase

lowering the bar for alternative energy to compete economically

Page 35: Solar Energy Physics 52. Outline Basics of today’s power generation The Sun Photovoltaic Cell Modules and systems A little economics Conclusion Quiz.

Venture Capital want into the act

• New Solar Energy companies– Better materials for the cell– More efficient cell production– Less us of silicon material– New mounting techniques

• Over next decade start-up companies will compete with multi-national companies until technology settles down to a pure production cost race