PRUTHIRAJ SWAIN12PS21F

Clean Solar Energy DSSC Technology

Outline

Introduction(Present Scenario in India)Background on Solar LightTypes of Solar cellHow a Silicon-Based Solar Cell WorksHow a Dye-Sensitized Cell WorksComparison Summary

Introduction : Energy-starved India is becoming a vibrant market for renewable energy.

This bodes well for a country that has often seen its industrial and economic growth inhibited by a truncated supply of conventional power.

Currently faces energy shortage of 8 % & a peak demand shortage of 11.6 %.

In order to sustain a growth rate of 8 %, it is estimated that the power generation capacity in India would have to increase to 306 GW in the next 10 years which is 1.7 times current levels.

Grid-connected renewable power accounts for as much as 20.2 GW – or 11% – of India's 182.3 GW of installed power capacity.

◦ The majority share (55% or 99.8 GW ) – by coal-based thermal power.

◦ Gas-fired thermal power, (10% or 17.7 GW),

◦ Hydropower (21% or 38.7 GW) and nuclear 2.6% with 4780 MW.

◦ India just had 2.12 megawatts of grid-connected solar generation capacity

Under the 11th Five Year Plan (ended March 2012), Only 52 GW of the 78.6 GW originally envisaged has been added,.

The 10th Plan (2002-07) only saw a meagre 21.2 GW capacity added, against a target of 41.1 GW.

The 12th Plan (2012-17) now aims for a capacity addition of 103.3 GW which includes commensurate transmission and distribution capacities.

Clean energy investments in India reached a record US$10.3bn in 2011, up 52% from the US$6.8bn invested in 2010 .This was the highest growth figure of any significant economy in the world, with the country accounting for 4% of global investments in clean energy. The large growth was driven by a 7-fold increase in funding for grid-connected solar projects.

Solar photovoltaic (PV) power plants totalling over 180 MW were set up in the country and off-grid installations of over 50 MW were completed as well.

What is Solar Energy? Energy produced by the Sun

Conversion of Sunlight into usable energy such as electricity and heat.

◦ Clean(No green house gases),

◦ renewable source of energy,

◦ Decentralization of power

◦ Saving eco-systems and livelihoods.

Harnessed by solar collection

methods such as solar cells & Concentrators

Conversion of Sunlight into usable energy such as electricity and heat.

Photovoltaic (solar) panel

Set of solar panels

Energy from the Sun is Abundant

Solar power systems installed in the areas defined by the darkdisks could meet the world's current Total energy demand

Solar Panel Use Today

Solar panels being tested on WalMart store

Solar panels on Microsoft building

Photovoltaic Solar Cells

Generate electricity directly from sunlight

2 Main types:

– Single-crystal silicon (traditional)

Widespread Expensive to manufacture

– Dye-sensitized (“nano”) Newer, less proven Inexpensive to manufacture Flexible

Silicon Based Solar Cell

Dye Sensitized Solar Cell

PV Technology Classification

1st Generation 2nd Generation

Silicon Crystalline Technology Thin Film Technology

Mono Crystalline PV Cells Amorphous Silicon PV Cells

Multi Crystalline PV Cells Poly Crystalline PV Cells

( Non-Silicon based)-CIS,CdTe

Solar Cells are Converters of Energy

Solar cells are devices that take light energy as input and convert it into electrical energy

A Little Background on Light

Different colours of light have different wavelengths and different energies

Absorption of Light by Atoms

Absorption occurs only when the energy of the light equals the energy of transition of an electron

Single electrontransition in an isolated atom

Absorption of Light by Ionic Compounds

Electrons can jump between “bands”

Incident light with energy >= than the “band gap” energy can be used to excite the electrons

So What Does this Mean for Solar Cells ?

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)

How a Silicon-Based Solar Cell Works

Light with energy greater than the band gap energy of Si is absorbed

Energy is given to an electron in the crystal lattice.The energy excites the electron; it is free to move.A positive “hole" is left in the electron’s place.This separation

of electrons and

holes creates a

voltage and a

current.

Silicon-Based Solar Cell Attributes

Expensive

– Made in high vacuum at high heat

– High manufacturing costs

Need TLC

– Fragile, rigid, thick

Long return on investment

– Takes 4 years to produce energy savings

equivalent to cost of production

How a Dye-Sensitized Cell Works

Light with high enough energy excites electrons in dye

molecules Excited electrons infused into semiconducting TiO2,

transported out of cellPositive “holes” left in dye moleculesSeparation of excited electrons and “holes” creates a

voltage and hence current.

Dye-Sensitized Solar Cells

Relatively inexpensive

– Made in non-vacuum setting mainly at room temperature

– Relatively simple manufacturing process

Need little TLC

– Thin, lightweight, flexible

Short return on investment

– Takes approx 3 months to produce energy savings equivalent to cost of production

Dye-Sensitized and Silicon-based Solar Cells Compared

Traditional

Expensive

– Need TLC

– Long return on investment

Dye-Sensitized

Relatively inexpensive

– Need little TLC

– Short return on investment

SummaryThe DSSC has a number of attractive features.Although its conversion efficiency is less than

the best thin-film cells, in theory its price/performance ratio should be good enough to allow them to compete with fossil fuel electrical generation by achieving grid parity.

North-western University researchers announced a solution to a primary problem of DSSCs, short useful life of the device.. The current efficiency is about half that of silicon cells, but the cells are lightweight and potentially of much lower cost to produce.

Further ReadingKonarka Technologies (Graetzel cells)

http://www.konarkatech.com/

PV Power Resource Site http://www.pvpower.com/

US DOE Photovoltaics http://www.eere.energy.gov/pv/

Key Center for Photovoltaic Engineeringhttp://www.pv.unsw.edu.au/

National Center for Photovoltaicshttp://www.nrel.gov/ncpv/

Thank You!!!(for patient hearing)