NEW HORIZONS IN SOLAR TECHNOLOGIES

1
NEW HORIZONS IN SOLAR TECHNOLOGIES

• Solar Energy Applications
• EnvS 116
• Asim Zia
• Department of Environmental Studies
• San Jose State University

2
Overview

• Thin film PV technologies Nanosolar
• http//www.nanosolar.com/
• Quantum dot solar concentrators Gallaghar et al.
  2006
• Energy and Nanotechnology

3
Quantum dot solar concentrators (QDSC)

• Buildings account for 20-30 of primary energy
  requirements
• (BI-)PV has high initial costs
• QDSC reduce the amount of PVs needed, thus
  lowering high initial costs

4
Principle of the QDSC
5
Higher Quantum Yield and Efficiency with Quantum
Dot Nanotechnology

• Flourescence Quantum Yield (QY)
• Ratio of the number of photons flourescing to the
  number of photons incident on the material
• Quantum Efficiency (QE)
• If QDs with high QE can be incorporated/designed
  into a suitable transparent media, then QDSC can
  be produced with electrical conversion
  efficiencies in the range of 20-23.

6
Absorption and emission of QDs with reference to
a silicon PV cell
7
Fabricated Mirrored Perspex Mould
8
QDSC with a PV cell
9
QDSC with a PV cell
10
Power output at different insolations
11
QDSC Efficiencies
12
Energy and Nanotechnology Grito 2005

• At 5 to 8 discount rate, PV electricity costs
  4.5 to 5.5 cents/kwH but at 12 to 16 discount
  rate or IRR, the cost goes up 7 to 9 cents/kwH
• Private sector operates at higher discount rate
  in the range of 12 to 16, therefore solar power
  is not attractive for power sector at this stage

13
Energy and Nanotechnology Grito 2005

• NREL model projects PV electricity costs to be
  dropped to a level of 1.5 to 2 cents/kwH in 20 to
  25 years could happen sooner if govt. supports
  RD
• But solar power does not get reflected in the big
  picture of energy projections, neither does solar
  get enough govt. RD funding 70 million annually
  in US compared to 1.5 billion for ethanol
  subsidies. Why?

14
Energy and Nanotechnology Grito 2005

• Policy makers are not correctly educated
• Not a clear understanding about the vast
  insolation potential in US and mexico
• Lack of solar lobbies as compared to coal and
  ethanol
• More funding in nanotechnology research for solar
  power distribution and storage is needed