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Nanoscience and Energy Lecture 3 Energy and Nanotechnology
| Date post: | 20-Jun-2015 |
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Nanoscience and Energy Lecture 3
Energy and Nanotechnology
Lecture 3. Energy and Nanotechnology Review of Alternate Energy
Sources
Review of Electronic Properties of
Solids:
Free- electron Fermi gas
Energy bands in Solids
Semiconductors and doping
pn junctions
Amorphous semiconductors
0
5
10
15
20
25
30
30 40 50 60 70 80 90 0 10 20
Gb/yr
Year
Middle East
USA
E-Europe/Asia
W-Europe
Rest of World
John A. Woollam, PV talk UNL 2007
World oil discovery rates declined since early 1960s; oil is consumed ~ 4 X greater rate than discovery rate.
Societal Drivers - Fossil Fuel Depletion D.E.Carlson, BP Solar
John A. Woollam, PV talk UNL 2007
Laherrere (2001): world oil production peaks ~ 2010.
Natural gas by ~ 2030.
Societal Drivers - Fossil Fuel Depletion D.E.Carlson, BP Solar
BioMass
• In 2003 — and for the fourth year in a row — biomass was the leading source of renewable energy in the United States, providing 2.9 Quadrillion Btu of energy. Biomass was the source for 47% of all renewable energy or 4% of the total energy produced in the United States). Agriculture and forestry residues, and in particular residues from paper mills, are the most common biomass resources used for generating electricity, and industrial process heat and steam and for a variety of biobased products. These are the organic byproducts of food, fiber, and forest production. In fact, 48% or 1.1 Quad Btu of biomass energy was consumed by the pulp and paper industry, solely using black liquor. Current biomass consumption in the United States is dominated by industrial use, largely derived from wood. Use of liquid transportation fuels such as ethanol and biodiesel, however, currently derived primarily from agricultural crops, is increasing dramatically. In 2003 ethanol produced from corn reached 2.81 billion gallons.
Hydropower
With 80,000 megawatts of generating
capacity, hydropower is the nation's largest renewable electricity source. Working with industry, the Wind and Hydropower Technologies Program pursues R&D to develop more environmentally friendly technologies to maintain the nation's existing hydropower capacity.
6.6.06 - 8.6.06 Clemson Summer School
Dr. Karl Molter / FH Trier / [email protected]
23
Solar irradiation in the USA
Shown is the average radiation received on a horizontal surface across the continental United States in the month of June. Units are in kWh/m2
6.6.06 - 8.6.06 Clemson Summer School
Dr. Karl Molter / FH Trier / [email protected]
24
Solar Irradiation worlwide (kWh/m² a) on horizontal surface
ENERGIA EOLICA
LA CONVERSION DE LA FUERZA DEL VIENTO A ENERGIA ELECTRICA EMPLEANDO AEROGENERADORES
ENERIA EOLICA ES UNA DE LAS MAS BARATAS DE DIFERENTES FORMAS DE ENERGIA RENOVABLE
Wind Energy
• In 2005, the United States installed more new wind energy capacity than any other country in the world. The new capacity, totaling 2,431 megawatts (MW), was worth more than $3 billion in generating equipment, and it brought the total national wind energy capacity to 9,149 MW. That's enough electricity to power 2.3 million average American households. In 2006, an additional 2,454 MW were installed, bringing the Nation's total installed capacity to 11,603 MW.
Centralized Solar Power
Review of Electronic Properties of Solids
Free Electron Fermi Gas
Energy Bands, Semiconductors, Doping
Hydrogen Molecule
6.6.06 - 8.6.06 Clemson Summer School
Dr. Karl Molter / FH Trier / [email protected]
46
energy-states in solids: Band-Pattern
Atom Molecule/Solid
ene
rgy-
stat
es
• • • • • • • •
6.6.06 - 8.6.06 Clemson Summer School
Dr. Karl Molter / FH Trier / [email protected]
47
energy-states in solids: Insulator
electron-energy
conduction-band
valence-band
Fermi- level EF
bandgap EG
(> 5 eV)
Figure 9.12. A valence electron jumping across the energy gap in pure
silicon resulting in the generation of a free electron and hole in the crystal:
(a) energy band model, (b) bond model.
Figure 9.13. Extrinsic n-type silicon doped with P donor atoms. (a) Energy
band diagram and (b) Bond model.
Figure 9.14. Extrinsic p-type silicon doped with B acceptor atoms. (a)
Energy band diagram and (b) Bond model.
6.6.06 - 8.6.06 Clemson Summer School
Dr. Karl Molter / FH Trier / [email protected]
53
energy-states in solids : metal / conductor
electron-energy
conduction-band
Fermi- level EF
6.6.06 - 8.6.06 Clemson Summer School
Dr. Karl Molter / FH Trier / [email protected]
54
energy-states in solids: semiconductor
electron-energy
conduction-band
valence-band
Fermi- level EF
bandgap EG
( 0,5 – 2 eV)
Figure 9.11. (a) Energy levels in an isolated silicon atom and (b) in a
silicon crystal of N atoms, illustrating the formation of energy bands. The
valence band contains 4N states and can accommodate all 4N valence
electrons.
pn Junctions
Amorphous Semiconductors
