nano based technology for renewable energy generation
TRANSCRIPT
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“NANO BASED TECHNOLOGY FOR RENEWABLE ENERGY GENERATION”
MR. ANIL KUMAR M.PHIL./PH.D. NANOSCIENCE, (2012-13)
CENTRE FOR NANOSCIENCE, CUG, SEC-30, GANDHINAGAR, [email protected]
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Introduction of Renewable Energy
Solar Electric Power Plants
What is a Photovoltaic Cell
How PV Cells Work
Dye-Sensitized and Silicon-based Solar
Cells Compared
Dye-Sensitized Solar Cells
So What Does this Mean for Solar Cells
Absorption of Light by Ionic
Compounds
Absorption of Light by Atoms
But Not All Energy is Converted
Application of Energy
Natural Forming sources of Energy,
Application and effects
Renewable sources of Energy,
Application and effects
Contents
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Nanotechnologies have significant potential to assist economies
in meeting their energy efficiency goals, enabling adoption of
new approaches, techniques and materials with a wide range of
applications, from efficient usage of traditional energy sources
to development and implementation of new generation
technologies based on renewable sources.
The nanotechnology impact is especially important for
renewable energy, which together with energy efficiency are
pillars of sustainable energy policy.
Introduction of Renewable Energy
4Sources: http://en.wikipedia.org/wiki/Solar_energ , http://www.fplenergy.com/portfolio/solar/facts.shtml#glance
Concentrated solar collector (parabolic)
Solar Electric Power Plants
• Main types:1. Solar thermal
energy• Has mirrored surface
that reflects sunlight to heat up liquid to make steam to generate electricity
2. Photovoltaic• Uses photovoltaic
cells that absorb direct sunlight
Array of mirrored solar collectors atFPL Energy site in California
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• Is a device of generating electrical power by converting solar radiation into direct current electricity using semiconductors that exhibit the photovoltaic effect.
• Photovoltaic power generation employs solar panels composed of a number of solar cells containing a photovoltaic material.
• Materials presently used for photovoltaics include monocrystalline silicon, polycrystalline silicon, amorphous silicon, cadmium telluride, and copper indium gallium selenide or sulfide….. etc.
How PV Cells Work?1. Photons in sunlight hit the solar panel and are absorbed by semiconducting materials, such as silicon.2. Electrons (negatively charged) are knocked loose from their atoms, allowing them to flow through the material to produce electricity.3. An array of solar cells converts solar energy into a usable amount of direct current (DC) electricity.
What is a Photovoltaic Cell?
6Sources: http://www.imo.uhasselt.be/polytech/images/zonnecel1.jpg, http://www.norfolksolar.co.uk/img/system.gif
• Dye-Sensitized “Nano”
1. Relatively inexpensive
2. Short return on investment
• Traditional “Single-crystal silicon”
1. Expensive
2. Long return on investment
Dye-Sensitized and Silicon-based Solar Cells Compared
7Source: http://www.imo.uhasselt.be/polytech/images/zonnecel1.jpg
• Relatively inexpensive1. Made in non-vacuum setting
mainly at room temperature
2. Relatively simple manufacturing process
• Need little TLC1. Thin, lightweight, flexible
• Short return on investment1. Takes approx 3 months to
produce energy savings equivalent to cost of production
Dye-Sensitized(“nano”) Solar Cells
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• In dye-sensitized solar cells…– Talk about highest
occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO)
• In single-crystal silicon solar cells…– Talk about “conduction
band” (excited states) and “valence band” (ground states)
So What Does this Mean for Solar Cells?
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• Electrons can jump between “bands”
• Incident light with energy ≥ than the “band gap” energy can be used to excite the electrons
Source: Image adapted from http://www.3dchem.com/molecules.asp?ID=135#
Absorption of Light by Ionic Compounds
10Sources: http://members.aol.com/WSRNet/tut/absorbu.htm, http://csep10.phys.utk.edu/astr162/lect/light/absorption.html
Single electron transition in an isolated atom
• Absorption occurs only when the energy of the light equals the energy of transition of an electron
Absorption of Light by Atoms
11Source: http://ebiomedia.com/prod/cyclops/images/image004.jpg
• Like chloroplasts in plants, solar cells can only absorb specific wavelengths of light.
• In both, light that isn’t absorbed is either transmitted through or reflected back.
• Whether a certain wavelength of lights gets absorbed depends on its energy.
Chlorophyll molecules absorb blue and red light, but reflect green light
But Not All Energy is Converted
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Application of Energy
Nanotechnology Approaches for Renewable Energy Generataion
Solar EnergyWind EnergyGeothermal steamBiomass
Natural form for sources of EnergyHydro-CarbonNuclear PowerHydro PowerAlternative Energy
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We know that, our main energy sources for human
activity are fossil and mineral fuels, nuclear and
hydroelectric sources.
They are very harmful to environment because
they cause global warning, ozone layer depletion,
biosphere and geosphere destruction, and
ecological devastation. Around 80 wt% of CO2
emissions in the world are originated by the
energy sector
Changes towards environmental improvements
are becoming more politically acceptable globally,
especially in developed countries. Society is
slowly moving towards seeking more sustainable
production methods, waste minimization, reduced
air pollution from vehicles, distributed energy
generation, conservation of native forests, and
reduction of greenhouse gas emissions.
Flow chart of Energy sources
Natural Forming sources of Energy, Application and effects
Source Figure: Elena Serrano, et al. 2009
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Nanotechnology is generating a lot
of attention these days and
therefore building great
expectations in renewable energy
challenges with nano-sciences in
21th century, the governments, and
industry.
For renewable energy are solar,
hydrogen and new generation
batteries and supercapacitors are
described as the most significant
examples of the contributions of
nanotechnology in the energy
sector.Source Figure: Elena Serrano, et al. 2009
Renewable sources of Energy, Application and effects
Flow chart of Renewable Energy sources
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THANKING YOU FOR A KIND ATTENTION…….
Source Figure : Elena Serrano, et al. 2009