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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, GUJARATkmr.nano@yahoo.com

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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